Analytical and Bioanalytical Chemistry - Aktuelle Forschungsartikel
Aktuelle Forschungsartikel: Analytische Chemie
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Hier aufgeführte Forschungsartikel:
Analytical and Bioanalytical Chemistry - Verlag: Springer
ABC ist eine internationale Zeitschrift mit dem Auftrag, exzellente Forschungsarbeiten aus allen Bereichen der analytischen und bioanalytischen Wissenschaft zu veröffentlichen.
Monepantel (MOP) belongs to a new class of anthelmintic drugs known as aminoacetonitrile derivatives. It was approved for
use in veterinary practice in Czech Republic in 2011. So far, biotransformation and transport of MOP in target animals have
been studied insufficiently, although the study of metabolic pathways of anthelmintics is very important for the efficacy
of safety of therapy and evaluation of the risk of drug–drug interactions. The aim of this study was to identify MOP metabolites
and to suggest the metabolic pathways of MOP in sheep. For this purpose, primary culture of ovine hepatocytes was used as
a model in vitro system. After incubation, medium samples and homogenates of hepatocytes were extracted separately using solid-phase
extraction. Analysis was performed using a hybrid quadrupole-time-of-flight analyzer with respect to high mass accuracy measurements
in full scan and tandem mass spectra for the confirmation of an elemental composition. The obtained results revealed S-oxidation
to sulfoxide and sulfone and arene hydroxylation as MOP phase I biotransformations. From phase II metabolites, MOP glucuronides,
sulfates, and acetylcysteine conjugates were found. Based on the obtained results, a scheme of the metabolic pathway of MOP
in sheep has been proposed.
Content Type Journal Article
Category Original Paper
Pages 1-8
DOI 10.1007/s00216-012-6584-4
Authors
Lucie Stuchlíková, Department of Biochemical Sciences, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Robert Jirásko, Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic
Ivan Vok?ál, Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Ji?í Lamka, Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Marcel Špulák, Department of Inorganic and Organic Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Michal Hol?apek, Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic
Barbora Szotáková, Department of Biochemical Sciences, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Hana Bártíková, Department of Biochemical Sciences, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Milan Pour, Department of Inorganic and Organic Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Lenka Skálová, Department of Biochemical Sciences, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Liquid chromatography coupled to multistage mass spectrometry (LC-MSn) is being used increasingly in pharmaceutical research and for quality control in herbal medicines because of its superior
sensitivity and selectivity. In this study, a rapid, high-resolution liquid chromatography-mass spectrometry (LC-MSn) method was developed to separate and identify alkaloids in the root extract of goldenseal, which is one of the 20 most popular
herbal supplements used worldwide. In total, 28 alkaloids were separated and characterized including one novel compound and
21 identified, or tentatively identified, for the first time in goldenseal. The current high-resolution LC-MSn method provides a rapid and definitive means of profiling the composition of goldenseal root and will provide a useful tool
in understanding the bioactivity of this medicinal plant.
Figure Extraction and Orbitrap LC-MSn analysis of Goldenseal root for alkaloid identification
Content Type Journal Article
Category Original Paper
Pages 1-12
DOI 10.1007/s00216-012-6539-9
Authors
Phuong Mai Le, Measurement Science and Standards, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada
Margaret McCooeye, Measurement Science and Standards, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada
Anthony Windust, Measurement Science and Standards, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada
With increasing multidrug resistance coupled to a poor development pipeline, clinicians are exploring antimicrobial combinations
to improve treatment outcomes. In vitro hollow-fiber infection model (HFIM) is employed to simulate human in vivo drug clearance
and investigate pharmacodynamic synergism of antibiotics. Our overarching aim was to optimize the HFIM-based pharmacokinetic
(PK) assay by using rifampicin and polymyxin B as probe drugs. An ultrapressure liquid chromatography tandem mass spectrometry
method was validated for the quantification of rifampicin and polymyxin B components. In vitro profiling studies demonstrated
that the experimental PK profiles of polymyxin B monotherapy were well correlated with the human population PK data while
monotherapy with rifampicin failed to achieve the expected maximum plasma concentration. Chemical stability studies confirmed
polymyxin B was stable in broth at 37 °C up to 12 h while rifampicin was unstable under the same conditions over 12 and 80 h.
The calculated mean clearance of rifampicin due to chemical degradation was 0.098 ml/min accounting for 12.2 % of its clinical
total clearance (CL?=?0.8 ml/min) based on population PK data. Our novel finding reinforces the importance to optimize HFIM-based
PK assay by performing chemical stability study so as to account for potential discrepancy between experimental and population
PK profiles of antimicrobial agents.
The new European regulations (e.g., REACH) require that Natural Complex Substances such as essential oils, absolutes, concretes,
and resinoids are registered. This need implies that the chemical composition of these complex mixtures is characterized as
exhaustively as possible in view of defining their toxicological risk. This study proposes an analysis strategy to be applied
to the chemical characterization of poplar absolute as an example of Natural Complex Substances of vegetable origin. In the
first part, the proposed strategy is described, and the advantages and the limitations related to the combination of conventional
analytical techniques such as gas chromatography (GC) without and with sample derivatization and high-performance liquid chromatography
(HPLC) are critically discussed. In the second part, the qualitative data obtained with GC and HPLC analysis of poplar bud
absolute confirm the sample complexity which mainly consists of phenolic components. Fourteen compounds (i.e., phenolic acids,
phenylpropanoids, and flavonoids) were then chosen as markers representative of the main classes of components characterizing
poplar bud absolute. The marker quantitation carried out by GC-SIM-MS and HPLC-PDA analyses gives similar results confirming
the reliability of both techniques. These results demonstrate that conventional analytical techniques can positively and effectively
contribute to the study of the the composition of Natural Complex Substances, i.e., matrices for which highly effective separation
is necessary, consisting mainly of isomers or homologous components. The combination of GC and HPLC techniques is ever more
necessary for routine quality control when conventional instrumentations are used.
Figure Elucidation of Natural Complex Substances (NCS)
Content Type Journal Article
Category Original Paper
Pages 1-13
DOI 10.1007/s00216-012-6537-y
Authors
Patrizia Rubiolo, Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Via Pietro Giuria 9, Turin, 10125 Italy
Cristina Casetta, Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Via Pietro Giuria 9, Turin, 10125 Italy
Cecilia Cagliero, Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Via Pietro Giuria 9, Turin, 10125 Italy
Hugues Brevard, Robertet SA, Research Division, 37 Avenue Sidi Brahim, 06130 Grasse, France
Barbara Sgorbini, Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Via Pietro Giuria 9, Turin, 10125 Italy
Carlo Bicchi, Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Via Pietro Giuria 9, Turin, 10125 Italy
Recently, clandestine drug lab operators have attempted to bypass controlled substances laws and regulations with “designer”
compounds chemically and pharmacologically similar to controlled substances. For example, “bath salts” have erupted onto the
scene as “legal highs” containing cathinone analogs that have produced severe side effects in users worldwide. These products
have sparked concern among law enforcement agencies, and emergency bans have been placed on the sale of such items. Despite
the increasing number of designer drugs available, there are few comprehensive screening techniques for their detection and
quantification in biological specimens. The liquid chromatography triple quadrupole tandem mass spectrometry (LC-QQQ-MS/MS)
method presented here encompasses over thirty important compounds within the phenethylamine, tryptamine, and piperazine designer
drug classes. Analytes were determined by LC-QQQ-MS/MS in the multiple-reaction monitoring mode after mixed-mode solid-phase
extraction. The bioanalytical method was fully validated according to recommended international guidelines. The assay was
selective for all analytes with acceptable accuracy and precision. Limits of quantification were in the range of 1–10 ng/mL
for each compound with limits of detection near 10 pg/mL. In order to evaluate its applicability in a forensic toxicological
setting, the validated method was used to analyze post-mortem specimens from two cases that were suspected of containing designer
drugs. The method was able to identify and quantify seven of these compounds at concentrations as low as 11 ng/mL. The method
should have wide applicability for rapid screening of important new drugs of abuse at high sensitivity in both post- and ante-mortem
forensic analysis.
Figure LC-MS chromatogram (intensity vs. retention time) of primary MRM transitions for 32 targeted analytes
Content Type Journal Article
Category Original Paper
Pages 1-15
DOI 10.1007/s00216-012-6548-8
Authors
Madeleine J. Swortwood, Department of Chemistry and Biochemistry and International Forensic Research Institute, Florida International University, Miami, FL 33199, USA
Diane M. Boland, Toxicology Laboratory, Miami–Dade Medical Examiner Department, Miami, FL 33136, USA
Anthony P. DeCaprio, Department of Chemistry and Biochemistry and International Forensic Research Institute, Florida International University, Miami, FL 33199, USA
Ambient mass spectrometry has attracted substantial attention in recent years. Among ambient ionization methods, thermal desorption
ionization stands out because of two attributes: (1) simplicity, rendering the technique suitable for in-field applications,
and (2) ability to couple with a variety of gas-phase ionization methods thereby broadening the range of molecules that can
be analyzed with this method. Here, we report on improving the performance of a direct analysis in real time (DART) source
by implementing atmospheric pressure photoionization (APPI) downstream of the desorption region. At identical desorption and
ion sampling conditions, APPI leads to detection of radical molecular ions from non-polar compounds that are absent from the
spectra generated by DART alone. Moreover, a factor of 3–5 improvement in sensitivity is observed using APPI for positive
ions commonly detected by DART and DART-APPI. Using helium and nitrogen as desorption gases, APPI shows identical performance
regardless of desorption gas type. In contrast, a dramatic decrease in sensitivity is observed for DART operated with nitrogen
compared to DART with helium. Comparable performance for DART and DART-APPI are observed in negative ion mode, although both
show a drastic improvement in the absence of the Vapur interface. This interface creates a differentially pumped chamber prior
to inlet of the mass spectrometer and reduces the mass spectrometer gas load when helium is used as desorption gas.
Content Type Journal Article
Category Original Paper
Pages 1-8
DOI 10.1007/s00216-012-6536-z
Authors
Kaveh Jorabchi, Syagen Technology Inc., a subsidiary of Morpho Detection, Inc., 1251 E. Dyer Rd., Santa Ana, CA 92705, USA
Karl Hanold, Syagen Technology Inc., a subsidiary of Morpho Detection, Inc., 1251 E. Dyer Rd., Santa Ana, CA 92705, USA
Jack Syage, Syagen Technology Inc., a subsidiary of Morpho Detection, Inc., 1251 E. Dyer Rd., Santa Ana, CA 92705, USA
A trend is observed in mass spectrometry, in which solid samples without prior dissolution and chromatographic separation
are brought directly into the ion source and are ionized, e.g., by corona discharge (Atmospheric Solids Analysis Probe) or
plasma (Direct Analysis in Real Time). The Direct Inlet Probe-atmospheric-pressure chemical ionization (APCI) ion source presented
here, which was coupled to a high-resolution quadrupole time-of-flight–mass spectrometer, differs from most of the other ion
sources in having temperature-programmed heating of the sample. The resulting possibility to reduce ion suppression and ion-molecule
reactions in the ion source was shown by the separation of two fatty acid methyl esters as a result of their boiling point
difference. Using caffeine as sample, certain source parameters such as the auxiliary gas flow, the drying gas flow, and the
position of the probe tip in the ion source were optimized. The ability to perform quantitative analyses was shown by the
linear concentration response (R2?=?0.9984) observed when analyzing different caffeine concentrations. An extract of a Chinese medicinal herb was used to examine
the reproducibility (relative standard deviations of the most abundant m/z signals were ?8.1 %). It was also possible to distinguish milled samples of Radix Angelicae sinensis and Radix Angelicae gigas from each other and to identify the coumarins they contain without sample preparation. Supplying synthetic air instead of
nitrogen to the ion source makes APCI in the negative mode possible as well; this was proven by the analysis of n-nonyl-?-d-maltoside.
Content Type Journal Article
Category Original Paper
Pages 1-9
DOI 10.1007/s00216-012-6531-4
Authors
Sonja Krieger, Institute for Pure and Applied Mass Spectrometry, University of Wuppertal, Gauss-Str. 20, 42119 Wuppertal, Germany
Alexandra von Trotha, Institute for Pure and Applied Mass Spectrometry, University of Wuppertal, Gauss-Str. 20, 42119 Wuppertal, Germany
Kelvin Sze-Yin Leung, Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Kowloon, HKSAR, China
Oliver J. Schmitz, Institute for Pure and Applied Mass Spectrometry, University of Wuppertal, Gauss-Str. 20, 42119 Wuppertal, Germany
Digestive diseases caused by flagellated bacteria are a huge public health problem worldwide and rapid detection methods are
needed for contaminated environments. In this study, we propose a method to detect patterns associated with pathogens based
on the properties of the innate immune system. Specifically, we use Toll-like receptor 5 (TLR5), a transmembrane protein that
specifically recognizes flagellin (the structural protein of bacterial flagella). TLR5, which was obtained by recombinant
production in insect cells, was immobilized into liposomes to form TLR5-proteoliposomes. Through surface plasmon resonance
(SPR) and competition flow cytometry assays, the sensitivity of proteoliposomes to recognize Escherichia coli and Salmonella typhimurium flagellin was evaluated. In addition, we compared the results obtained by immobilizing anti-flagellin antibodies into liposomes.
The results of the flagellin-affinity tests, expressed as an SPR kinetic rate constant ratio in the equilibrium equation KD?=?kd/ka, showed values of 13.8?×?10?9 and 7.73?×?10?9?M for the TLR5-proteoliposomes and anti-flagellin antibodies, respectively, against S. typhimurium. The anti-flagellin affinity results for E. coli showed KD of 84.1?×?10?8?M for SPR assays and KD of 3.5?×?10?8?M for competitive flow cytometry, which was used as a detection system without the immobilization of proteoliposomes. This
research demonstrates the practical possibility of using proteoliposomes as recognition elements in the generation of systems
for the rapid detection of flagellated bacteria, which could help avoid consumption of contaminated food by humans and thereby
prevent intestinal infections.
Content Type Journal Article
Category Original Paper
Pages 1-15
DOI 10.1007/s00216-012-6523-4
Authors
Y. Olguín, Biotechnology Center, Federico Santa Maria Technical University, Valparaíso, Chile
P. Villalobos, Biotechnology Center, Federico Santa Maria Technical University, Valparaíso, Chile
L. G. Carrascosa, Nanobiosensor and Bioanalytical Applications (nanoB2A), CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Bellaterra, Barcelona, Spain
M. Young, Biotechnology Center, Federico Santa Maria Technical University, Valparaíso, Chile
E. Valdez, Department of Chemistry, Federico Santa Maria Technical University, Valparaíso, Chile
L. Lechuga, Nanobiosensor and Bioanalytical Applications (nanoB2A), CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Bellaterra, Barcelona, Spain
R. Galindo, Department of Civil Engineering, Federico Santa Maria Technical University, Valparaíso, Chile
Epidermal growth factor receptor (EGFR) plays a major role in cell migration and invasion and is considered to be the primary
source of activation of various malignant tumors. To gain insight into how elevated levels of EGFR influence cellular function,
particularly cell motility, we used a quartz crystal microbalance with dissipation monitoring (QCM-D) to examine restructuring
of focal adhesions in MCF-10A cells induced by epidermal growth factor. Engineered cells that overexpress epidermal growth
factor receptor (EGFR) exhibited a very different kinetic profile from wildtype MCF-10A cells that have a lower level of EGFR
with a higher rate for the initial disassembly of focal adhesion and a much lower rate for the later reassembly of focal adhesions.
It is conceivable that these effects exhibited by EGFR-overexpressing cells may promote the initiation and maintenance of
a more favorable adhesion state for cell migration. This study has demonstrated the capability of the dissipation monitoring
function of the QCM-D to quantitatively assess kinetic aspects of cellular processes with a high temporal resolution and sensitivity.
Figure Characterization of the effects of the expression level of epidermal growth factor receptor on the kinetics of the epidermal
growth factor-induced restructuring of focal adhesions with the quartz crystal microbalance with dissipation monitoring.
Content Type Journal Article
Category Short Communication
Pages 1-6
DOI 10.1007/s00216-012-6558-6
Authors
Marcela P. Garcia, Chemistry Department, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA
Ammar Shahid, Chemistry Department, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA
Jennifer Y. Chen, Chemistry Department, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA
Jun Xi, Chemistry Department, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA
This paper describes the characterisation of liposome-type nanoparticles (NPs) dispersed in a beverage matrix. Characterisation
is based on a two-step procedure: first, liposomes are separated on the basis of size in the nanometre range by use of hydrodynamic
chromatography (HDC); second, chemical characterisation is performed by use of MALDI–TOF mass spectrometry (MS). Characterisation
of three types of Coatsome liposome, a commercially available type of empty liposome, was investigated. All three liposome
types, Coatsome A?=?anionic, N?=?neutral, and C?=?cationic, gave single peaks in HDC, reflecting diameters of 153, 187, and
205 nm, respectively. Subsequent MALDI–TOF MS in positive mode furnished major signals at m/z?=?734.5 ([M?+?H]+ adduct) and m/z?=?756.6 ([M?+?Na]+ adduct) of l-(?)-dipalmitoylphosphatidylcholine (DPPC) monomer and dimeric adducts at m/z?=?1468.1 and m/z?=?1490.1, respectively. MALDI–TOF MS in negative mode gave a signal at m/z?=?721.3 ([M???H]? adduct) of l-(?)-dipalmitoylphosphatidylglycerol (DPPG), except for Coatsome C which lacks this phospholipid. After HDC separation of
Coatsome A NPs the major DPPC and DPPG signals can be detected in the expected fractions by use of MALDI–TOF MS in positive
and negative modes, respectively. Validation of the analytical strategy revealed linearity (R2?>?0.99), repeatability (relative standard deviation <10 %), and reproducibility (relative standard deviation between days
<10 %) were good, recovery was 61?±?5 %, and the limit of quantification was 1 mg?mL?1 in this matrix. With 4 mg Coatsome A mL?1 20 out of 20 samples furnished the 734.5 and 756.6 signals typical of DPPC in MALDI–TOF MS characterisation.
Content Type Journal Article
Category Original Paper
Pages 1-9
DOI 10.1007/s00216-012-6530-5
Authors
Johannes P. F. G. Helsper, RIKILT Wageningen UR, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands
Ruud J. B. Peters, RIKILT Wageningen UR, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands
Although in many cases Pb isotopic analysis can be relied on for provenance determination of ancient bronzes, sometimes the
use of “non-traditional” isotopic systems, such as those of Cu and Sn, is required. The work reported on in this paper aimed
at revising the methodology for Cu and Sn isotope ratio measurements in archaeological bronzes via optimization of the analytical
procedures in terms of sample pre-treatment, measurement protocol, precision, and analytical uncertainty. For Cu isotopic
analysis, both Zn and Ni were investigated for their merit as internal standard (IS) relied on for mass bias correction. The
use of Ni as IS seems to be the most robust approach as Ni is less prone to contamination, has a lower abundance in bronzes
and an ionization potential similar to that of Cu, and provides slightly better reproducibility values when applied to NIST
SRM 976 Cu isotopic reference material. The possibility of carrying out direct isotopic analysis without prior Cu isolation
(with AG-MP-1 anion exchange resin) was investigated by analysis of CRM IARM 91D bronze reference material, synthetic solutions,
and archaeological bronzes. Both procedures (Cu isolation/no Cu isolation) provide similar ?65Cu results with similar uncertainty budgets in all cases (±0.02–0.04 per mil in delta units, k?=?2, n?=?4). Direct isotopic analysis of Cu therefore seems feasible, without evidence of spectral interference or matrix-induced
effect on the extent of mass bias. For Sn, a separation protocol relying on TRU-Spec anion exchange resin was optimized, providing
a recovery close to 100 % without on-column fractionation. Cu was recovered quantitatively together with the bronze matrix
with this isolation protocol. Isotopic analysis of this Cu fraction provides ?65Cu results similar to those obtained upon isolation using AG-MP-1 resin. This means that Cu and Sn isotopic analysis of bronze
alloys can therefore be carried out after a single chromatographic separation using TRU-Spec resin. Tin isotopic analysis
was performed relying on Sb as an internal standard used for mass bias correction. The reproducibility over a period of 1 month
(n?=?42) for the mass bias-corrected Sn isotope ratios is in the range of 0.06–0.16 per mil (2 s), for all the ratios monitored.
Content Type Journal Article
Category Original Paper
Pages 1-14
DOI 10.1007/s00216-012-6542-1
Authors
Eleonora Balliana, Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, 9000 Ghent, Belgium
Maite Aramendía, Centro Universitario de la Defensa, Carretera de Huesca s/n, 50090 Zaragoza, Spain
Martin Resano, Department of Analytical Chemistry, University of Zaragoza, Calle Pedro Cerbuna 12, 50009 Zaragoza, Spain
Carlo Barbante, Department of Environmental Sciences, Informatics and Statistics, Ca’ Foscari University of Venice, Calle Larga S. Marta 2137, 30123 Venice, Italy
Frank Vanhaecke, Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, 9000 Ghent, Belgium
Di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) is a promising analogue of the dipyridyl thiosemicarbazone
class currently under development as a potential anti-cancer drug. In fact, this class of agents shows markedly greater anti-tumor
activity and selectivity than the clinically investigated thiosemicarbazone, Triapine®. However, further development of DpC
requires detailed data concerning its metabolism. Therefore, we focused on the identification of principal phase I and II
metabolites of DpC in vitro. DpC was incubated with human liver microsomes/S9 fractions and the samples were analyzed using
ultra-performance liquid chromatography (UPLCTM) with electrospray ionization quadrupole-time-of-flight (Q-TOF) mass spectrometry. An Acquity UPLC BEH C18 column was implemented with 2 mM ammonium acetate and acetonitrile in gradient mode as the mobile phase. The chemical structures
of metabolites were proposed based on the accurate mass measurement of the protonated molecules as well as their main product
ions. Ten phase I and two phase II metabolites were detected and structurally described. The metabolism of DpC occurred via
oxidation of the thiocarbonyl group, hydroxylation and N-demethylation, as well as the combination of these reactions. Conjugates of DpC and the metabolite, M10, with glucuronic acid were also observed as phase II metabolites. Neither sulfate nor glutathione conjugates were detected.
This study provides the first information about the chemical structure of the principal metabolites of DpC, which supports
the development of this promising anti-cancer drug and provides vital data for further pharmacokinetic and in vivo metabolism
studies.
Figure Proposed metabolic pathways of DpC
Content Type Journal Article
Category Original Paper
Pages 1-11
DOI 10.1007/s00216-012-6562-x
Authors
Ján Stariat, Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Petra Kova?íková, Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Radim Ku?era, Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Ji?í Klimeš, Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
Danuta S. Kalinowski, Iron Metabolism and Chelation Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, NSW 2006, Australia
Des R. Richardson, Iron Metabolism and Chelation Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, NSW 2006, Australia
Raimo A. Ketola, Centre for Drug Research, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 Helsinki, Finland
A general method is presented for the identification of radiometabolites in plasma of human and monkey subjects after administration
of positron emission tomography (PET) radioligands. The radiometabolites are first produced in vitro, using liver microsomes,
subsequently separated using fast radio-liquid chromatography (radio-LC), and individually collected and identified by ultra
high-performance liquid chromatography/quadrupole-time of flight-mass spectrometry in MS and MSE mode. Fast radio-LC provided superior resolution compared to conventional radio-LC, resulting in separation of a greater
number of metabolites. The radiometabolites produced in vivo are then compared to and identified based on the in vitro results.
This approach was applied to three PET radioligands, [11C]flumazenil, [18F]FE-PE2I, and [11C]PBR28, resulting in the identification of five, two, and one radiometabolites, respectively. This procedure can easily be
adopted to identify the radiometabolites produced in vivo from a variety of PET radioligands.
Content Type Journal Article
Category Original Paper
Pages 1-8
DOI 10.1007/s00216-012-6541-2
Authors
Nahid Amini, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, 171 76 Sweden
Ryuji Nakao, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, 171 76 Sweden
Magnus Schou, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, 171 76 Sweden
Christer Halldin, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, 171 76 Sweden
New methods for determination of explosive substances as, for example, 2,4,6-trinitrotoluene (TNT), in a rapid way and at
low cost are highly required. An electrochemical platform has been here developed with good characteristics of low dimension,
fast response, low cost, and high selectivity. It is based on a commercially available screen printed cell with graphite ink
working and auxiliary electrodes and a silver ink quasi-reference electrode. The whole cell is covered with a thick layer
of cation exchanging acrylic polymer molecularly imprinted with 2,4,6-trinitrotoluene. The polymeric layer acts at the same
time as electrolytic medium and selective receptor. It has been demonstrated that, in this medium, 2,4,6-trinitrotoluene is
electroactive at graphite electrode, being reduced by a non-reversible reaction. The peak current (differential pulse voltammogram)
is proportional to TNT concentration with limit of detection for TNT around 5?×?10?7?M and linearity range up to 2?×?10?5?M. The selectivity for TNT relative to other reducible compounds as, for example, nitroaromatic derivatives, and to other
possible interfering substances, as negatively charged ions, is good. Measurements can be performed in not de-aerated solution
and in small volumes (20 ?l), so that the proposed platform is very promising for in situ determinations.
Figure Molecularly imprinted polymer for TNT as selective artificial receptor and ionic medium of the electrochemical cell
Content Type Journal Article
Category Original Paper
Pages 1-12
DOI 10.1007/s00216-012-6553-y
Authors
M. Pesavento, Dipartimento di Chimica, Università di Pavia, via Taramelli 12, 27100 Pavia, Italy
G. D’Agostino, Dipartimento di Chimica, Università di Pavia, via Taramelli 12, 27100 Pavia, Italy
G. Alberti, Dipartimento di Chimica, Università di Pavia, via Taramelli 12, 27100 Pavia, Italy
R. Biesuz, Dipartimento di Chimica, Università di Pavia, via Taramelli 12, 27100 Pavia, Italy
D. Merli, Dipartimento di Chimica, Università di Pavia, via Taramelli 12, 27100 Pavia, Italy
Poplar (Populus) and birch (Betula) species are widely distributed throughout the northern hemisphere, where they are foundation species in forest ecosystems
and serve as important sources of pulpwood. The ecology of these species is strongly linked to their foliar chemistry, creating
demand for a rapid, inexpensive method to analyze phytochemistry. Our study demonstrates the feasibility of using near-infrared
reflectance spectroscopy (NIRS) as an inexpensive, high-throughput tool for determining primary (e.g., nitrogen, sugars, starch)
and secondary (e.g., tannins, phenolic glycosides) foliar chemistry of Populus and Betula species, and identifies conditions necessary for obtaining reliable quantitative data. We developed calibrations with high
predictive power (residual predictive deviations???7.4) by relating phytochemical concentrations determined with classical
analytical methods (e.g., spectrophotometric assays, liquid chromatography) to NIR spectra, using modified partial least squares
regression. We determine that NIRS, although less sensitive and precise than classical methods for some compounds, provides
useful predictions in a much faster, less expensive manner than do classical methods.
Graphical abstract Near-infrared reflectance spectroscopy with calibrations based on modified partial least squares regression can provide quantitative
measurements of foliar nitrogen, carbohydrate, tannin, and phenolic glycoside content in poplar and birch
Content Type Journal Article
Category Original Paper
Pages 1-12
DOI 10.1007/s00216-012-6513-6
Authors
Kennedy F. Rubert-Nason, Dept. of Entomology, University of Wisconsin, 237 Russell Labs, 1630 Linden Drive, Madison, WI 53706, USA
Liza M. Holeski, Dept. of Entomology, University of Wisconsin, 237 Russell Labs, 1630 Linden Drive, Madison, WI 53706, USA
John J. Couture, Dept. of Entomology, University of Wisconsin, 237 Russell Labs, 1630 Linden Drive, Madison, WI 53706, USA
Adam Gusse, Dept. of Entomology, University of Wisconsin, 237 Russell Labs, 1630 Linden Drive, Madison, WI 53706, USA
Daniel J. Undersander, Dept. of Agronomy, University of Wisconsin, Madison, WI 53706, USA
Richard L. Lindroth, Dept. of Entomology, University of Wisconsin, 237 Russell Labs, 1630 Linden Drive, Madison, WI 53706, USA
The cyanobacterial neurotoxin ?-N-methylamino-l-alanine (BMAA) is an amino acid that is putatively associated with the pathology of amyotrophic lateral sclerosis/Parkinsonism–dementia
complex (ALS-PDC) disease. It raises serious health risk concerns since cyanobacteria are ubiquitous thus making human exposure
almost inevitable. The identification and quantification of BMAA in cyanobacteria is challenging because it is present only
in trace amounts and occurs alongside structurally similar compounds such as BMAA isomers. This work describes an enhanced
liquid chromatography/tandem mass spectrometry platform that can distinguish BMAA from its isomers ?-amino-N-methyl-alanine, N-(2-aminoethyl) glycine (AEG), and 2,4-diaminobutyric acid, thus ensuring confident identification of BMAA. The method's sensitivity
was improved fourfold by a post-column addition of acetonitrile. The instrument and method limits of detection were shown
to be 4.2 fmol/injection (or 0.5 pg/one column) and 0.1 ?g/g dry weight of cyanobacteria, respectively. The quantification
method uses synthesized deuterated BMAA as an internal standard and exhibits good linearity, accuracy, and precision. Matrix
effects were also investigated, revealing an ion enhancement of around 18 %. A lab-cultured cyanobacterial sample (Leptolyngbya PCC73110) was analyzed and shown to contain about 0.73 ?g/g dry weight BMAA. The isomer AEG, whose chromatographic properties
closely resemble those of BMAA, was also detected. These results highlight the importance of distinguishing BMAA from its
isomers for reliable identification as well as providing a sensitive and accurate quantification method for measuring trace
levels of BMAA in cyanobacterial samples.
Content Type Journal Article
Category Original Paper
Pages 1-10
DOI 10.1007/s00216-012-6550-1
Authors
Liying Jiang, Department of Analytical Chemistry, Stockholm University, 10691 Stockholm, Sweden
Eric Johnston, Department of Organic Chemistry, Stockholm University, 10691 Stockholm, Sweden
K. Magnus Åberg, Department of Analytical Chemistry, Stockholm University, 10691 Stockholm, Sweden
Ulrika Nilsson, Department of Analytical Chemistry, Stockholm University, 10691 Stockholm, Sweden
Leopold L. Ilag, Department of Analytical Chemistry, Stockholm University, 10691 Stockholm, Sweden
The pyrolysis process of pine wood, a promising biofuel feedstock, has been studied with tunable synchrotron vacuum ultraviolet
photoionization mass spectrometry. The mass spectra at different photon energies and temperatures as well as time-dependent
profiles of several selected species during pine wood pyrolysis process were measured. Based on the relative contents of three
lignin subunits, the data indicate that pine wood is typical of softwood. As pyrolysis temperature increased from 300 to 700 °C,
some more details of pyrolysis chemistry were observed, including the decrease of oxygen content in high molecular weight
species, the observation of high molecular weight products from cellulose chain and lignin polymer, and potential pyrolysis
mechanisms for some key species. The formation of polycyclic aromatic hydrocarbons (PAHs) was also observed, as well as three
series of pyrolysis products derived from PAHs with mass difference of 14 amu. The time-dependent profiles show that the earliest
products are formed from lignin, followed by hemicellulose products, and then species from cellulose.
Figure The pyrolysis study of pine wood based on synchrotron vacuum ultraviolet photoionization mass spectrometry.
Content Type Journal Article
Category Original Paper
Pages 1-9
DOI 10.1007/s00216-012-6516-3
Authors
Junjie Weng, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
Liangyuan Jia, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
Shaobo Sun, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
Yu Wang, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
Xiaofeng Tang, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
Zhongyue Zhou, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
Fei Qi, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
Extraction of phosphopeptides from rather complex biological samples has been a tough issue for deep and comprehensive investigation
into phosphoproteomes. In this paper, we present a series of Ti-doped mesoporous silica (Ti-MPS) materials with tunable composition
and controllable morphology for highly efficient enrichment of phosphopeptides. By altering the molar ratio of silicon to
titanium (Si/Ti) in the precursor, the external morphology, Ti content, internal long-rang order, and surface area of Ti-MPS
were all modulated accordingly with certain regularity. Tryptic digests of standard phosphoprotein ?- and ?-casein were employed
to assess the phosphopeptide enrichment capability of Ti-MPS series. At the Si/Ti molar ratio of 8:1, the optimum enrichment
performance with admirable sensitivity and capacity was achieved. The detection limit for ?-casein could reach 10 fmol, and
15 phosphopeptides from the digest of ?-casein were resolved in the spectrum after enrichment, both superior to the behavior
of commercial TiO2 materials. More significantly, for the digest of human placenta mitochondria, 396 phosphopeptides and 298 phosphoproteins
were definitely detected and identified after enrichment with optimized Ti-MPS material, demonstrating its remarkable applicability
for untouched phosphoproteomes. In addition, this research also opened up a universal pathway to construct a composition-tunable
functional material in pursuit of the maximum performance in applications.
Figure From human placenta mitochondria to MS
Content Type Journal Article
Category Original Paper
Pages 1-11
DOI 10.1007/s00216-012-6554-x
Authors
Fuqiang Wang, State Key Laboratory of Reproductive Medicine, Analytical & Testing Center, Nanjing Medical University, Nanjing, 210029 China
Zhonghua Shi, Nanjing Maternity and Child Health Care Hospital, Nanjing, 210029 China
Fan Hu, State Key Laboratory of Reproductive Medicine, Analytical & Testing Center, Nanjing Medical University, Nanjing, 210029 China
Zhengrong Xia, State Key Laboratory of Reproductive Medicine, Analytical & Testing Center, Nanjing Medical University, Nanjing, 210029 China
Ling Wang, State Key Laboratory of Reproductive Medicine, Analytical & Testing Center, Nanjing Medical University, Nanjing, 210029 China
We developed a fluorescent assay to conveniently determine the kinetics of protein sulfation, which is essential for understanding
interface between protein sulfation and protein–protein interactions. Tyrosylprotein sulfotransferase (TPST) catalyzes protein
sulfation using 3?-phosphate 5?-phosphosulfate (PAPS) as sulfuryl group donor. In this report, PAPS was regenerated following
sulfuryl group transfer between adenosine 3?,5?-diphosphate and 4-methylumbelliferyl sulfate catalyzed by phenol sulfotransferase
(PST). The TPST and PST coupled enzyme platform continuously generated fluorescent 4-methylumbelliferone (MU) that was used
to real-time monitor protein sulfation. Using a recombinant N utilization substance protein A fused Drosophila melanogaster tyrosylprotein sulfotransferase, we demonstrated that the activity of TPST determined through MU fluorescence directly correlated
with protein sulfation. Kinetic constants obtained with small P-selectin glycoprotein ligand-1 peptide (PSGL-1 peptide, MW
1541) or its large glutathione S-transferase fusion protein (GST-PSGL-1, MW 27833) exhibited significant variation. This assay can be further developed to
a high-throughput method for the characterization of TPSTs and for the identification and screening of their protein substrates.
Content Type Journal Article
Category Technical Note
Pages 1-5
DOI 10.1007/s00216-012-6540-3
Authors
Bo-Han Chen, Department of Biological Science and Technology, National Chiao Tung University, 75 Po-Ai Street, Hsinchu, 30050, Taiwan
Chen-Chu Wang, Department of Biological Science and Technology, National Chiao Tung University, 75 Po-Ai Street, Hsinchu, 30050, Taiwan
Lu-Yi Lu, Department of Biological Science and Technology, National Chiao Tung University, 75 Po-Ai Street, Hsinchu, 30050, Taiwan
Kuo-Sheng Hung, Department of Neurosurgery, Center of Excellence for Clinical Trial and Research, Taipei Medical University-Wan Fang Medical Center, Taipei, 116 Taiwan
Yuh-Shyong Yang, Department of Biological Science and Technology, National Chiao Tung University, 75 Po-Ai Street, Hsinchu, 30050, Taiwan
The current state of chiral separations by thin-layer chromatography using chiral stationary phases is reviewed. Both stationary
phases essentially constituted by the chiral selector and those obtained by the impregnation of achiral plates with appropriate
chiral selectors are described. Particular attention is paid to commercial and non-commercial cellulose and cellulose-derivative
plates, as well as commercially available Chiralplate™, which are currently the most widely used. Some of the most important
results obtained to date are reported and discussed; the examples provided illustrate the very wide range of structurally
different solutes that can be readily resolved into their enantiomers by planar chromatographic methods. Special attention
is paid to the discussion of the retention and resolution factors that influence chiral discrimination. The quantitative analysis
of enantiomers is also discussed, especially from the point of view of determination of enantiomeric purity.
Content Type Journal Article
Category Review
Pages 1-22
DOI 10.1007/s00216-012-6514-5
Authors
Massimo Del Bubba, Department of Chemistry, Via della Lastruccia 3, 50019 Sesto Fiorentino (Florence), Italy
Leonardo Checchini, Department of Chemistry, Via della Lastruccia 3, 50019 Sesto Fiorentino (Florence), Italy
Luciano Lepri, Department of Chemistry, Via della Lastruccia 3, 50019 Sesto Fiorentino (Florence), Italy
Erratum to: New “hyphenated” CPC-HPLC-DAD-MS strategy for simultaneous isolation, analysis and identification of phytochemicals: application to xanthones from Garcinia mangostana
Content Type Journal Article
Category Erratum
Pages 1-1
DOI 10.1007/s00216-012-6545-y
Authors
Thomas Michel, Institut de Chimie Organique et Analytique, Université d’Orléans–CNRS, UMR CNRS 7311, BP 67059, 45067 Orléans Cedex 2, France
Emilie Destandau, Institut de Chimie Organique et Analytique, Université d’Orléans–CNRS, UMR CNRS 7311, BP 67059, 45067 Orléans Cedex 2, France
Laëtitia Fougère, Institut de Chimie Organique et Analytique, Université d’Orléans–CNRS, UMR CNRS 7311, BP 67059, 45067 Orléans Cedex 2, France
Claire Elfakir, Institut de Chimie Organique et Analytique, Université d’Orléans–CNRS, UMR CNRS 7311, BP 67059, 45067 Orléans Cedex 2, France
This investigation focused on direct comparison of two popular multidimensional liquid–gas chromatography (LC–GC) systems,
the Y-interface (retention gap approach) and the syringe-based interface (programmed temperature vaporizer approach). Such
transfer devices are structurally very different, and could potentially have a substantial effect on the outcome of a specific
application. In this work the application was a topic of much current interest, determination of mineral oil saturated hydrocarbon
(MOSH) contamination of a series of food products (rice, pasta, icing sugar, olive oil); the final results were then compared.
The two LC–GC methods developed were validated for linearity over the calibration range, analyte discrimination, precision,
accuracy, and limits of detection and quantification. No significant differences were found between the two approaches.
Figure Direct comparison between the Y/LC-GC and the PTV/LC-GC results, on two rice samples
Content Type Journal Article
Category Original Paper
Pages 1-8
DOI 10.1007/s00216-012-6535-0
Authors
Giorgia Purcaro, Dipartimento di Scienze degli Alimenti, University of Udine, via Sondrio 2/A, 33100 Udine, Italy
Mariosimone Zoccali, Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università degli Studi di Messina, viale Annunziata, 98168 Messina, Italy
Peter Quinto Tranchida, Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università degli Studi di Messina, viale Annunziata, 98168 Messina, Italy
Laura Barp, Dipartimento di Scienze degli Alimenti, University of Udine, via Sondrio 2/A, 33100 Udine, Italy
Sabrina Moret, Dipartimento di Scienze degli Alimenti, University of Udine, via Sondrio 2/A, 33100 Udine, Italy
Lanfranco Conte, Dipartimento di Scienze degli Alimenti, University of Udine, via Sondrio 2/A, 33100 Udine, Italy
Paola Dugo, Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università degli Studi di Messina, viale Annunziata, 98168 Messina, Italy
Luigi Mondello, Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università degli Studi di Messina, viale Annunziata, 98168 Messina, Italy
In this work, the application of multivariate curve resolution-alternating least squares (MCR-ALS) is proposed for extracting
information from multitechnique fused multivariate data (UV–VIS absorption, fluorescence, and liquid chromatography–mass spectrometry)
gathered during the biosynthesis of violacein pigment. Experimental data sets were pretreated and arranged in a row-wise augmented
data matrix before their chemometric investigation. Five different chemical components were resolved. Kinetic and spectral
information about these components were obtained and their relationship with violacein biosynthesis was established. Three
new chemical compounds with molar masses of 453, 465, and 479 u, until now not reported in the literature, were identified
and proposed as intermediates in the biosynthesis of other indolocarbazoles. The precursor (tryptophan), one intermediate
(deoxyviolacein), and the final product (violacein) of violacein biosynthesis were identified and characterized using the
proposed approach. The chemometric procedure based on the MCR-ALS method has proved to be a powerful tool to investigate violacein
biosynthesis and its application can be easily extended to the study of other bioprocesses.
Content Type Journal Article
Category Original Paper
Pages 1-10
DOI 10.1007/s00216-012-6507-4
Authors
Clecio Dantas, Institute of Chemistry, University of Campinas—UNICAMP, Campinas, P.O. Box 6154, 13084-971 Brazil
Romà Tauler, Department of Environmental Chemistry, IDAEA-CSIC, 08034 Barcelona, Spain
Márcia Miguel Castro Ferreira, Institute of Chemistry, University of Campinas—UNICAMP, Campinas, P.O. Box 6154, 13084-971 Brazil
A fully simultaneous ICP-MS, based on a compact Mattauch–Herzog geometry with a permanent magnet and a large, spatially resolving
semiconductor ion detector covering the complete inorganic relevant mass range from 6Li to 238U in a single measurement, has been used to determine isotope ratios and assess achievable isotope ratio precisions. Measurements
of the 235/238U isotopic ratio, chosen as example for an isotopic system with a disparate isotope ratio, yielded a precision of 0.05 % relative.
To evaluate the expected multi-isotope ratio measurement capabilities of the system used, several isotope ratios spanning
a wide range (6/7Li, 84/86Sr, 87/86Sr, 88/86Sr, 204/207Pb, 206/207Pb and 208/207Pb) were measured simultaneously, using a synthetic multi-element standard as sample. Very satisfying isotope ratio precisions,
between 0.5 and 0.04 % relative, depending on the isotope ratio in question were found during the simultaneous multi-isotope
ratio measurements. Together with a brief description of the system and measurement procedures employed for this technical
note, the results achieved are assessed in view of other existing ICP-MS-based isotope ratio techniques.
Figure Fully simultaneous Mattauch-Herzog geometry MS with a spatially resolving semiconductor ion detector (schematic)
A method based on reverse atom transfer radical polymerization (R-ATRP) and molecular crowding has been used for design and
synthesis of monolithic molecularly imprinted polymers (MIPs) capable of recognizing ibuprofen (IBU). 4-Vinylpyridine (4-VP)
was used as the functional monomer, and ethylene glycol dimethacrylate (EDMA) was the crosslinking monomer. Azobisisobutyronitrile
(AIBN)–CuCl2–N,N,N?,N?,N?-pentamethyldiethylenetriamine (PMDETA) was used as the initiating system. Compared with conventional radical polymerization-based
IBU-MIPs, the imprinting effects of the obtained IBU-MIPs was enhanced, suggesting the merit of combination of reverse ATRP
and molecular crowding. In addition, it was found that the polymerization time of the molecularly imprinted monolithic column,
the amount of template, the degree of crosslinking, and the composition of mobile phase greatly affected retention of the
template and the performance of molecular recognition
.
Figure Schematic representation of molecular imprinting under molecular crowding conditions in the presence of R-ATRP
Content Type Journal Article
Category Original Paper
Pages 1-9
DOI 10.1007/s00216-012-6497-2
Authors
Lu Ban, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics), School of Pharmacy, Tianjin Medical University, Tianjin, 300070 China
Liang Zhao, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics), School of Pharmacy, Tianjin Medical University, Tianjin, 300070 China
Bang-Li Deng, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics), School of Pharmacy, Tianjin Medical University, Tianjin, 300070 China
Yan-Ping Huang, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics), School of Pharmacy, Tianjin Medical University, Tianjin, 300070 China
Zhao-Sheng Liu, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics), School of Pharmacy, Tianjin Medical University, Tianjin, 300070 China
Unregulated growth promoter use in food-producing animals is an issue of concern both from food safety and animal welfare
perspectives. However, the monitoring of such practices is analytically challenging due to the concerted actions of users
to evade detection. Techniques based on the monitoring of biological responses to exogenous administrations have been proposed
as more sensitive methods to identify treated animals. This study has, for the first time, profiled plasma proteome responses
in bovine animals to treatment with nortestosterone decanoate and 17?-oestradiol benzoate, followed by dexamethasone administration.
Two-dimensional fluorescence differential in-gel electrophoresis analysis revealed a series of hepatic and acute-phase proteins
within plasma whose levels were up- or down-regulated within phases of the treatment regime. Surface plasmon resonance (SPR)
immuno-assays were developed to quantify responses of identified protein markers during the experimental treatment study with
a view to developing methods which can be used as screening tools for growth promoter abuse detection. SPR analysis demonstrated
the potential for plasma proteins to be used as indicative measures of growth promoter administrations and concludes that
the sensitivity and robustness of any detection approach based on plasma proteome analysis would benefit from examination
of a range of proteins representative of diverse biological processes rather being reliant on specific individual markers.
Content Type Journal Article
Category Original Paper
Pages 1-9
DOI 10.1007/s00216-012-6534-1
Authors
Terence F. McGrath, Institute of Agri-food and Land Use, School of Biological Sciences, Queen’s University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG Northern Ireland, UK
Jeroen A. van Meeuwen, Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80.175, 3508 TD Utrecht, The Netherlands
Anne-Cécile Massart, Laboratory of Mass Spectometry, CART, GIGA, Institut de Chimie, Bat. B6c, University of Liège, Liege, Belgium
Edwin de Pauw, Laboratory of Mass Spectometry, CART, GIGA, Institut de Chimie, Bat. B6c, University of Liège, Liege, Belgium
Philippe Delahaut, Département Santé, CER Groupe, Rue du Carmel 1, Marloie, 6900 Belgium
Jos Buijs, GE Healthcare Bio-Sciences, Rapsgatan 23, 75184 Uppsala, Sweden
Aldert A. Bergwerff, Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80.175, 3508 TD Utrecht, The Netherlands
Christopher T. Elliott, Institute of Agri-food and Land Use, School of Biological Sciences, Queen’s University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG Northern Ireland, UK
Mark H. Mooney, Institute of Agri-food and Land Use, School of Biological Sciences, Queen’s University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG Northern Ireland, UK
The application of asymmetric-flow field flow fractionation (A4F) for low aspect ratio gold nanorod (GNR) fractionation and
characterization was comprehensively investigated. We report on two novel aspects of this application. The first addresses
the analytical challenge involved in the fractionation of positively charged nanoparticles by A4F, due to the interaction
that exists between the negatively charged native membrane and the analyte. We show that the mobile phase composition is a
critical parameter for controlling fractionation and mitigating the membrane-analyte interaction. A mixture of ammonium nitrate
and cetyl trimethyl ammonium bromide at different molar ratios enables separation of GNRs with high recovery. The second aspect
is the demonstration of shape-based separation of GNRs in A4F normal mode elution (i.e., Brownian mode). We show that the
elution of GNRs is due both to aspect ratio and a steric-entropic contribution for GNRs with the same diameter. This latter
effect can be explained by their orientation vector inside the A4F channel. Our experimental results demonstrate the relevance
of the theory described by Beckett and Giddings for non-spherical fractionation (Beckett and Giddings, J Colloid and Interface Sci 186(1):53–59, 1997). However, it is shown that this theory has its limit in the case of complex GNR mixtures, and that shape (i.e., aspect ratio)
is the principal material parameter controlling elution of GNRs in A4F; the apparent translational diffusion coefficient of
GNRs increases with aspect ratio. Finally, the performance of the methodology developed in this work is evaluated by the fractionation
and characterization of individual components from a mixture of GNR aspect ratios.
Content Type Journal Article
Category Original Paper
Pages 1-12
DOI 10.1007/s00216-012-6547-9
Authors
Julien Gigault, Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8520, Gaithersburg, MD 20899-8520, USA
Tae Joon Cho, Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8520, Gaithersburg, MD 20899-8520, USA
Robert I. MacCuspie, Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8520, Gaithersburg, MD 20899-8520, USA
Vincent A. Hackley, Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8520, Gaithersburg, MD 20899-8520, USA
The study of individual cells with infrared (IR) microspectroscopy often requires living cells to be cultured directly onto
a suitable substrate. The surface effect of the specific substrates on the cell growth—viability and associated biochemistry—as
well as on the IR analysis—spectral interference and optical artifacts—is all too often ignored. Using the IR beamline, MIRIAM
(Diamond Light Source, UK), we show the importance of the substrate used for IR absorption spectroscopy by analyzing two different
cell lines cultured on a range of seven optical substrates in both transmission and reflection modes. First, cell viability
measurements are made to determine the preferable substrates for normal cell growth. Successively, synchrotron radiation IR
microspectroscopy is performed on the two cell lines to determine any genuine biochemically induced changes or optical effect
in the spectra due to the different substrates. Multivariate analysis of spectral data is applied on each cell line to visualize
the spectral changes. The results confirm the advantage of transmission measurements over reflection due to the absence of
a strong optical standing wave artifact which amplifies the absorbance spectrum in the high wavenumber regions with respect
to low wavenumbers in the mid-IR range. The transmission spectra reveal interference from a more subtle but significant optical
artifact related to the reflection losses of the different substrate materials. This means that, for comparative studies of
cell biochemistry by IR microspectroscopy, it is crucial that all samples are measured on the same substrate type.
Figure Cell separation by PCA due to the refractive index of the substrate used, revealing transmission artifact.
Content Type Journal Article
Category Original Paper
Pages 1-14
DOI 10.1007/s00216-012-6521-6
Authors
Katia Wehbe, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
Jacob Filik, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
Mark D. Frogley, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
Gianfelice Cinque, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
The molecular structure of three low-molecular-weight resins used as paint varnishes has been characterized by use of an approach
based on three different mass spectrometric techniques. We investigated the ketone resin MS2A, the aldehyde resin Laropal
A81, and the hydrocarbon resin Regalrez 1094, now commonly used in restoration. To date, the molecular structures of these
resins have not been completely elucidated. To improve current knowledge of the chemical composition of these materials, information
obtained by gas chromatography–mass spectrometry (GC/MS), pyrolysis–gas chromatography–mass spectrometry (Py/GC/MS), and electrospray
ionization mass spectrometry (ESI–Q–ToF) was combined. Analysis, in solution, of the whole polymeric fraction of the resins
by flow-injection ESI–Q–ToF, and of the non-polymeric fraction by GC–MS, enabled us to identify previously unreported features
of the polymer structures. In addition, the Py–GC/MS profiles that we obtained will help to enhance the databases currently
available in the literature. The proposed approach can be extended to other low-molecular-weight resins used as varnishes
in conservation.
Content Type Journal Article
Category Original Paper
Pages 1-19
DOI 10.1007/s00216-012-6502-9
Authors
I. Bonaduce, Department of Chemistry and Industrial Chemistry, University of Pisa, via Risorgimento 35, 56126 Pisa, Italy
M. P. Colombini, Department of Chemistry and Industrial Chemistry, University of Pisa, via Risorgimento 35, 56126 Pisa, Italy
I. Degano, Department of Chemistry and Industrial Chemistry, University of Pisa, via Risorgimento 35, 56126 Pisa, Italy
F. Di Girolamo, Department of Chemistry and Industrial Chemistry, University of Pisa, via Risorgimento 35, 56126 Pisa, Italy
J. La Nasa, Department of Chemistry and Industrial Chemistry, University of Pisa, via Risorgimento 35, 56126 Pisa, Italy
F. Modugno, Department of Chemistry and Industrial Chemistry, University of Pisa, via Risorgimento 35, 56126 Pisa, Italy
S. Orsini, Department of Chemistry and Industrial Chemistry, University of Pisa, via Risorgimento 35, 56126 Pisa, Italy
Caffeine is utilised as a reference for permeation studies in dermatology and cosmetology. The present work aimed to monitor
the permeation of a caffeine solution through the skin. For this purpose, Raman and infrared studies were performed. Raman
microspectroscopy permitted a dynamic follow-up of the caffeine diffusion. In complementary, infrared microimaging provided
information of the caffeine localization in the skin by applying multivariate statistical processing on skin tissue sections.
Herein, we prove the possibility of tracking low concentrations of caffeine through the skin and we highlight some experimental
limitations of vibrational spectroscopies.
Content Type Journal Article
Category Original Paper
Pages 1-8
DOI 10.1007/s00216-012-6512-7
Authors
Sana Tfaili, MéDIAN Unit, CNRS FR3481, Faculty of Pharmacy, University of Reims Champagne-Ardenne (URCA), 51 rue Cognacq Jay, 51096 Reims, France
Cyril Gobinet, MéDIAN Unit, CNRS FR3481, Faculty of Pharmacy, University of Reims Champagne-Ardenne (URCA), 51 rue Cognacq Jay, 51096 Reims, France
Gwendal Josse, Research and Development, Dermo-cosmetics, Pierre Fabre Institute, 31025 Toulouse Cedex 3, France
Jean-François Angiboust, MéDIAN Unit, CNRS FR3481, Faculty of Pharmacy, University of Reims Champagne-Ardenne (URCA), 51 rue Cognacq Jay, 51096 Reims, France
Arlette Baillet, EA 4041 Group Chimie Analytique de Paris Sud, Faculty of Pharmacy, Paris Sud University, 92296 Châtenay Malabry, France
Michel Manfait, MéDIAN Unit, CNRS FR3481, Faculty of Pharmacy, University of Reims Champagne-Ardenne (URCA), 51 rue Cognacq Jay, 51096 Reims, France
Olivier Piot, MéDIAN Unit, CNRS FR3481, Faculty of Pharmacy, University of Reims Champagne-Ardenne (URCA), 51 rue Cognacq Jay, 51096 Reims, France
Letter to the Editor regarding “Simultaneous determination of ?9-tetrahydrocannabinol and 11-nor-9-carboxy-?9-tetrahydrocannabinol in oral fluid using isotope dilution liquid chromatography tandem mass spectrometry”
Content Type Journal Article
Category Letter to the Editor
Pages 1-3
DOI 10.1007/s00216-012-6515-4
Authors
Marie Fabritius, Forensic Toxicology and Chemistry Unit, University Center of Legal Medicine, Rue du Bugnon 21, 1011 Lausanne, Switzerland
Christian Giroud, Forensic Toxicology and Chemistry Unit, University Center of Legal Medicine, Rue du Bugnon 21, 1011 Lausanne, Switzerland
Temozolomide (TMZ) is an antineoplastic alkylating agent with activity against serious and aggressive types of brain tumours.
It has been postulated that TMZ exerts its antitumor activity via its spontaneous degradation at physiological pH. The in
vitro evaluation of the interaction of TMZ and its final metabolites, 5-aminoimidazole-4-carboxamide (AIC) and methyldiazonium
ion, with double-stranded DNA (dsDNA) was studied using differential pulse voltammetry at a glassy carbon electrode. The DNA
damage was electrochemically detected following the changes in the oxidation peaks of guanosine and adenosine residues. The
results obtained revealed the decrease of the dsDNA oxidation peaks with incubation time, showing that TMZ and AIC/methyldiazonium
ion interact with dsDNA causing its condensation. Furthermore, the experiments of the in situ TMZ and AIC/methyldiazonium
ion–dsDNA interaction using the multilayer dsDNA-electrochemical biosensor confirmed the condensation of dsDNA caused by these
species and showed evidence for a specific interaction between the guanosine residues and TMZ metabolites, since free guanine
oxidation peak was detected. The oxidative damage caused to DNA bases by TMZ metabolites was also detected electrochemically
by monitoring the appearance of the 8-oxoguanine/2,8-dyhydroxyadenine oxidation peaks. Nondenaturing agarose gel electrophoresis
of AIC/methyldiazonium ion–dsDNA samples confirmed the occurrence of dsDNA condensation and oxidative damage observed in the
electrochemical results. The importance of the dsDNA-electrochemical biosensor in the in situ evaluation of TMZ–dsDNA interactions
is clearly demonstrated.
Content Type Journal Article
Category Original Paper
Pages 1-8
DOI 10.1007/s00216-012-6546-x
Authors
Ilanna C. Lopes, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal
S. Carlos B. Oliveira, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal
Ana Maria Oliveira-Brett, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal
The application of LC/MS-TOF method combined with stable isotope dilution assay was studied for determination of thiamine,
riboflavin, nicotinamide, nicotinic acid, pantothenic acid, pyridoxal, and pyridoxine in food. Nutritional yeast powder was
used as a model food matrix. Acid extraction was compared with various enzymatic treatments in ammonium formate buffer to
find a suitable method for the conversion of more complex vitamers into the same forms as the used isotope-labeled internal
standards. The enzyme preparations ?-amylase, takadiastase, ?-glucosidase, and acid phosphatase were all able to liberate
thiamine and riboflavin. The diastatic enzyme preparations ?-amylase and takadiastase also expressed proteolytic side activities
resulting in the formation of small peptides which interfered with the mass spectra of thiamine and riboflavin. Liberation
of nicotinamide and pantothenic acid from NAD+ and CoA, respectively, could not be achieved with any of the studied enzyme preparations. Hydrochloric acid extraction at
121 °C for 30 min was found to be destructive to pantothenic acid, but increased the liberation of pyridoxal.
Figure Comparison of different extraction methods for B complex vitamins determination in nutritional yeast
Content Type Journal Article
Category Original Paper
Pages 1-10
DOI 10.1007/s00216-012-6538-x
Authors
Kristel Hälvin, Department of Food Processing, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia
Toomas Paalme, Department of Food Processing, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia
Ildar Nisamedtinov, Department of Food Processing, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia
Mitochondrial fatty acid oxidation (FAO) disorders are caused by defects in one of the FAO enzymes that regulates cellular
uptake of fatty acids and free carnitine. An in vitro probe acylcarnitine (IVP) assay using cultured cells and tandem mass
spectrometry is a tool to diagnose enzyme defects linked to most FAO disorders. Extracellular acylcarnitine (AC) profiling
detects carnitine palmitoyltransferase-2, carnitine acylcarnitine translocase, and other FAO deficiencies. However, the diagnosis
of primary carnitine deficiency (PCD) or carnitine palmitoyltransferase-1 (CPT1) deficiency using the conventional IVP assay
has been hampered by the presence of a large amount of free carnitine (C0), a key molecule deregulated by these deficiencies.
In the present study, we developed a novel IVP assay for the diagnosis of PCD and CPT1 deficiency by analyzing intracellular
ACs. When exogenous C0 was reduced, intracellular C0 and total AC in these deficiencies showed specific profiles clearly distinguishable
from other FAO disorders and control cells. Also, the ratio of intracellular to extracellular C0 levels showed a significant
difference in cells with these deficiencies compared with control. Hence, intracellular AC profiling using the IVP assay under
reduced C0 conditions is a useful method for diagnosing PCD or CPT1 deficiency.
Content Type Journal Article
Category Original Paper
Pages 1-7
DOI 10.1007/s00216-012-6532-3
Authors
Jamiyan Purevsuren, Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya, Izumo, Shimane 693-8501, Japan
Hironori Kobayashi, Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya, Izumo, Shimane 693-8501, Japan
Yuki Hasegawa, Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya, Izumo, Shimane 693-8501, Japan
Kenji Yamada, Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya, Izumo, Shimane 693-8501, Japan
Tomoo Takahashi, Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya, Izumo, Shimane 693-8501, Japan
Masaki Takayanagi, Division of Metabolism, Chiba Children’s Hospital, Chiba, 266-0007 Japan
Toshiyuki Fukao, Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Gifu, 501-1194 Japan
Seiji Fukuda, Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya, Izumo, Shimane 693-8501, Japan
Seiji Yamaguchi, Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya, Izumo, Shimane 693-8501, Japan
This review outlines advances in designing modified electrodes with switchable properties controlled by various physical and
chemical signals. Irradiation of the modified electrode surfaces with various light signals, changing the temperature of the
electrolyte solution, application of a magnetic field or electrical potentials, changing the pH of the solutions, and addition
of chemical/biochemical substrates were used to change reversibly the electrode activity. The increasing complexity in the
signal processing was achieved by integration of the switchable electrode interfaces with biomolecular information processing
systems mimicking Boolean logic operations, thus allowing activation and inhibition of electrochemical processes on demand
by complex combinations of biochemical signals. The systems reviewed range from simple chemical compositions to complex mixtures
modeling biological fluids, where the signal substrates were added at normal physiological and elevated pathological concentrations.
The switchable electrode interfaces are considered for future biomedical applications where the electrode properties will
be modulated by the biomarker concentrations reflecting physiological conditions.
Figure Modified electrodes were reversibly switched between active and inactive states by various physical and chemical signals.
Content Type Journal Article
Category Review
Pages 1-14
DOI 10.1007/s00216-012-6525-2
Authors
Evgeny Katz, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY 13699-5810, USA
Segiy Minko, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY 13699-5810, USA
Jan Halámek, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY 13699-5810, USA
Kevin MacVittie, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY 13699-5810, USA
Kenneth Yancey, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY 13699-5810, USA
Erratum to: Characterization of nanochannel delivery membrane systems for the sustained release of resveratrol and atorvastatin: new perspectives on promoting heart health
Content Type Journal Article
Category Erratum
Pages 1-1
DOI 10.1007/s00216-012-6544-z
Authors
Juliana Sih, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Shyam S. Bansal, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Stefano Filippini, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Silvia Ferrati, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Kunal Raghuwansi, NanoMedical Systems, Inc, Austin, TX 77030, USA
Erika Zabre, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Eugenia Nicolov, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Daniel Fine, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Mauro Ferrari, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Ganesh Palapattu, Department of Urology, University of Michigan, Ann Arbor, MI, USA
Alessandro Grattoni, Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Room # R8-216, Houston, TX 77030, USA
Ionic liquid-salt aqueous two-phase extraction coupled with high-performance liquid chromatography with ultraviolet detection
was developed for the determination of sulfonamides in water and food samples. In the procedure, the analytes were extracted
from the aqueous samples into the ionic liquid top phase in one step. Three sulfonamides, sulfamerazine, sulfamethoxazole,
and sulfamethizole were selected here as model compounds for developing and evaluating the method. The effects of various
experimental parameters in extraction step were studied using two optimization methods, one variable at a time and Box–Behnken
design. The results showed that the amount of sulfonamides did not have effect on the extraction efficiency. Therefore, a
three-level Box–Behnken experimental design with three factors, which combined the response surface modeling, was used to
optimize sulfonamides extraction. Under the most favorable extraction parameters, the detection limits (S/N?=?3) and quantification limits (S/N?=?10) of the proposed method for the target compounds were achieved within the range of 0.15–0.3 ng/mL and 0.5–1.0 ng/mL
from spiked samples, respectively, which are lower than or comparable with other reported approaches applied to the determination
of the same compounds. Finally, the proposed method was successfully applied to the determination of sulfonamide compounds
in different water and food samples and satisfactory recoveries of spiked target compounds in real samples were obtained.
Content Type Journal Article
Category Original Paper
Pages 1-11
DOI 10.1007/s00216-012-6511-8
Authors
Juan Han, School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013 China
Yun Wang, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Yan Liu, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Yanfang Li, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Yang Lu, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Yongsheng Yan, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Liang Ni, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Histone acetyltransferases (HATs) catalyze the acetylation of specific lysine residues in histone and nonhistone proteins.
Recent studies showed that acetylation is widely distributed among cellular proteins, suggestive of diverse functions of HATs
in cellular pathways. Nevertheless, currently available assays for HAT activity study are still quite limited. Here, we evaluated
a series of thiol-sensitive fluorogenic compounds for the detection of the enzymatic activities of different HAT proteins.
Upon conjugation to the thiol group of HSCoA, these molecules gain enhanced quantum yields and strong fluorescence, permitting
facile quantitation of HAT activities. We investigated and compared the assay performances of these fluorogenic compounds
for their capability as HAT activity reporters, including kinetics of reaction with HSCoA, influence on HAT activity, and
fluorescence amplification factors. Our data suggest that CPM and coumarin maleic acid ester are excellent HAT probes owing
to their fast reaction kinetics and dramatic fluorescence enhancement during the HAT reaction. Further, the microtiter plate
measurements show that this fluorescent approach is robust and well suited for adaption to high-throughput screening of small
molecule inhibitors of HATs, highlighting the value of this assay strategy in new drug discovery.
Content Type Journal Article
Category Original Paper
Pages 1-11
DOI 10.1007/s00216-012-6522-5
Authors
Tielong Gao, Department of Chemistry, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
Chao Yang, Department of Chemistry, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
Yujun George Zheng, Department of Chemistry, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
Letter to the Editor regarding “Quantification of Paraquat, MPTP, and MPP+ in brain tissue using microwave-assisted solvent extraction (MASE) and high-performance liquid chromatography–mass spectrometry”
Content Type Journal Article
Category Letter to the Editor
Pages 1-1
DOI 10.1007/s00216-012-6503-8
Authors
Brian Buckley, Rutgers University–EOHSI, 170 Frelinghuysen Road, Piscataway, NJ 08854, USA
Matrix-assisted laser/desorption ionization (MALDI) mass-spectrometric imaging (MSI), also known as MALDI imaging, is a powerful
technique for mapping biological molecules such as endogenous proteins and peptides in human skin tissue sections. A few groups
have endeavored to apply MALDI-MSI to the field of skin research; however, a comprehensive article dealing with skin tissue
sections and the application of various matrices and enzymes is not available. Our aim is to present a multiplex method, based
on MALDI-MSI, to obtain the maximum information from skin tissue sections. Various matrices were applied to skin tissue sections:
(1) 9-aminoacridine for imaging metabolites in negative ion mode; (2) sinapinic acid to obtain protein distributions; (3)
?-cyano-4-hydroxycinnamic acid subsequent to on-tissue enzymatic digestion by trypsin, elastase, and pepsin, respectively,
to localize the resulting peptides. Notably, substantial amounts of data were generated from the distributions retrieved for
all matrices applied. Several primary metabolites, e.g. ATP, were localized and subsequently identified by on-tissue postsource
decay measurements. Furthermore, maps of proteins and peptides derived from on-tissue digests were generated. Identification
of peptides was achieved by elution with different solvents, mixing with ?-cyano-4-hydroxycinnamic acid, and subsequent tandem
mass spectrometry (MS/MS) measurements, thereby avoiding on-tissue MS/MS measurements. Highly abundant peptides were identified,
allowing their use as internal calibrants in future MALDI-MSI analyses of human skin tissue sections. Elastin as an endogenous
skin protein was identified only by use of elastase, showing the high potential of alternative enzymes. The results show the
versatility of MALDI-MSI in the field of skin research. This article containing a methodological perspective depicts the basics
for a comprehensive comparison of various skin states.
Figure Matrix-assisted laser/desorption ionization (MALDI) mass-spectrometric imaging (MSI), also known as MALDI imaging, is a powerful
technique for mapping biological molecules in human skin tissue sections. In this body of work, a multiplex method, based
on MALDI-MSI, is presented to obtain maximum information from skin tissue sections. Therefore, various matrices were applied
to skin tissue sections: (1) 9-aminoacridine (9-AA) for imaging small molecules in negative ion mode; (2) sinapinic acid (SA)
to obtain protein distributions; (3) ?-cyano-4-hydroxycinnamic acid (?-HCHA) subsequent to on-tissue enzymatic digestion by
trypsin, elastase, and pepsin, respectively, to localize the resulting peptides. Of note, identification of metabolites was
achieved by post-source decay (PSD) MALDI, and proteins were identified subsequent to enzymatic digestion via the resulting
peptides which were eluted from the skin tissue section and afterwards analyzed with use of a tandem time-of-flight (ToF)
mass spectrometer. The application of alternative enzymes, such as pepsin and elastase, is highlighted within this article
The uncertainties of stable isotope results depend not only on the technical aspects of measurements, but also on how raw
data are normalized to one of the international isotope scales. The inconsistency in the normalization methods used and in
the selection of standards may lead to substantial differences in the results obtained. Therefore, unification of the data
processing protocols employed is highly desirable. The best performing methods are two-point or multipoint normalization methods
based on linear regression. Linear regression is most robust when based on standards that cover the entire range of ? values typically observed in nature, regardless of the ? values of the samples analysed. The uncertainty can be reduced by 50 % if measurements of two different standards are performed
four times, or measurements of four standards are performed twice, with each batch of samples. Chemical matrix matching between
standards and samples seems to be critical for ?18O of nitrate or ?2H of hair samples (thermal conversion/elemental analyser), for example; however, it is not necessarily always critical for
all types of samples and techniques (e.g. not for most ?15N and ?13C elemental analyser analyses). To ensure that all published data can be recalculated, if ? values of standards or the isotope scales are to be updated, the details of the normalization technique and the ? values of the standards used should always be clearly reported.
Content Type Journal Article
Category Review
Pages 1-9
DOI 10.1007/s00216-012-6517-2
Authors
Grzegorz Skrzypek, West Australian Biogeochemistry Centre, School of Plant Biology, The University of Western Australia, M090, 35 Stirling Highway, Crawley, WA 6009, Australia
Four new Standard Reference Materials (SRMs) have been developed to assist in the quality assurance of chemical contaminant
measurements required for human biomonitoring studies, SRM 1953 Organic Contaminants in Non-Fortified Human Milk, SRM 1954
Organic Contaminants in Fortified Human Milk, SRM 1957 Organic Contaminants in Non-Fortified Human Serum, and SRM 1958 Organic
Contaminants in Fortified Human Serum. These materials were developed as part of a collaboration between the National Institute
of Standards and Technology (NIST) and the Centers for Disease Control and Prevention (CDC) with both agencies contributing
data used in the certification of mass fraction values for a wide range of organic contaminants including polychlorinated
biphenyl (PCB) congeners, chlorinated pesticides, polybrominated diphenyl ether (PBDE) congeners, and polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners. The certified mass fractions of the organic contaminants in unfortified
samples, SRM 1953 and SRM 1957, ranged from 12 ng/kg to 2200 ng/kg with the exception of 4,4?-DDE in SRM 1953 at 7400 ng/kg
with expanded uncertainties generally <14 %. This agreement suggests that there were no significant biases existing among
the multiple methods used for analysis.
Figure Comparison of Concentrations of Selected Compounds in Human Serum and Human Milk Standard Reference Materials (SRMs)
Content Type Journal Article
Category Original Paper
Pages 1-9
DOI 10.1007/s00216-012-6524-3
Authors
Michele M. Schantz, Analytical Chemistry Division, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, MD 20899, USA
Gauthier Eppe, Mass Spectrometry Laboratory, University of Liège, Allée de la Chimie, 4000 Liège, Belgium
Jean-François Focant, Mass Spectrometry Laboratory, University of Liège, Allée de la Chimie, 4000 Liège, Belgium
Jennifer M. Keller, Analytical Chemistry Division, NIST, 331 Fort Johnson Road, Charleston, SC 29412, USA
Stefan D. Leigh, Statistical Engineering Division, NIST, 100 Bureau Drive, Gaithersburg, MD 20899, USA
Donald G. Patterson Jr, Organic Analytical Toxicology, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, USA
Adam L. Pintar, Statistical Engineering Division, NIST, 100 Bureau Drive, Gaithersburg, MD 20899, USA
Katherine E. Sharpless, Analytical Chemistry Division, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, MD 20899, USA
Andreas Sjödin, Organic Analytical Toxicology, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, USA
Wayman E. Turner, Organic Analytical Toxicology, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, USA
Stacy S. Vander Pol, Analytical Chemistry Division, NIST, 331 Fort Johnson Road, Charleston, SC 29412, USA
Stephen A. Wise, Analytical Chemistry Division, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, MD 20899, USA
Graphene-nanosheet-based highly porous magnetite nanocomposites (GN-HPMNs) have been prepared using a simple solvothermal
method and used as an immobilization matrix for the fabrication of a solid-state electrochemiluminescence (ECL) sensor on
paper-based chips. Highly porous Fe3O4 nanocrystal clusters were coated with acrylate and wrapped tightly on the skeleton of graphene nanosheets. The structures
and sizes of the GN-HPMNs could be tuned by varying the proportions of the solvents ethylene glycol and diethylene glycol.
Then, the relatively highly porous ones with an average diameter of about 65 nm were combined with Nafion to form composite
films on an electrode surface for immobilization of Ru(bpy)32+ (bpy is 2,2?-bipyridine). Because of their porosity, negatively charged surface, and cooperative characteristics of magnetic
nanomaterials and graphene, under an external magnetic field, the GN-HPMNs ensured effective immobilization, excellent electron
transfer, and long-term stability of Ru(bpy)32+ in the composite film. The sensor developed exhibited excellent reproducibility with a relative standard deviation of 0.65 %
for 30 continuous cycles. It was found to be much more favorable for detecting compounds containing tertiary amino groups
and DNAs with guanine and adenine. A detection limit (signal-to-noise ratio of 3) of 5.0 nM was obtained for tripropylamine.
As an application example, 0.5 nM single-nucleotide mismatch could be detected. This was the first attempt to introduce magnetic
nanomaterials and an external magnetic field into paper-based chips. The sensor developed has the advantages of high sensitivity,
good stability, and wide potential applicability as well as simplicity, low cost, and good disposability.
Figure Schematic diagram of using graphene-nanosheet-based highly porous magnetite nanocomposites for fabrication of a solid-state
electrochemiluminescence sensor on paper-based chips and application example of the developed sensor for single-nucleotide
mismatch discrimination
Content Type Journal Article
Category Original Paper
Pages 1-10
DOI 10.1007/s00216-012-6510-9
Authors
Yuanhong Xu, State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
Zhaozi Lv, State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
Yong Xia, State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
Yanchao Han, State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
Baohua Lou, State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
Erkang Wang, State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
For many analytical purposes, direct laser ionization of liquids is desirable. Several studies on supported droplets, free
liquid jets, and ballistically dispensed microdroplets have been conducted, yet detailed knowledge of the underlying mechanistics
in ion formation is still missing. This contribution introduces a simple combination of IR-MALDI mass spectrometry and an
acoustical levitation device for contactless confinement of the liquid sample. The homebuilt ultrasonic levitator supports
droplets of several millimeters in diameter. These droplets are vaporized by a carbon dioxide laser in the vicinity of the
atmospheric pressure interface of a time of flight mass spectrometer. The evaporation process is studied by high repetition
rate shadowgraphy experiments elucidating the ballistic evaporation of the sample and revealing strong confinement of the
vapor by the ultrasonic field of the trap. Finally, typical mass spectra for pure glycerol/water matrix and lysine as an analyte
are presented with and without the addition of trifluoracetic acid, and the ionization mechanism is briefly discussed. The
technique is a promising candidate for a reproducible mass spectrometric detection scheme for the field of microfluidics.
Figure CO2 laser evaporation of an acoustic levitated droplet followed by time of flight mass analysis
Content Type Journal Article
Category Original Paper
Pages 1-6
DOI 10.1007/s00216-012-6500-y
Authors
Arne Stindt, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Str. 11, 12489 Berlin, Germany
Merwe Albrecht, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Str. 11, 12489 Berlin, Germany
Ulrich Panne, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Str. 11, 12489 Berlin, Germany
Jens Riedel, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Str. 11, 12489 Berlin, Germany
Phytohormones act at relatively low concentrations as major regulatory factors of plant growth and development, and cross
talk of phytohormones is currently of great interest throughout the plant science community. To meet this demand, a method
that is capable of simultaneously analyzing diverse plant hormones is essential. This paper introduces a high-performance
liquid chromatographic separation technique coupled with sensitive and selective ion trap mass spectrometry to simultaneously
determine 24 or more acidic and alkaline phytohormones, including auxin, cis- and trans-abscisic acid, 11 cytokinins, and 10 gibberellins, in a single injection of sample. A binary solid-phase extraction using
Oasis MCX cartridges for cations and Oasis MAX cartridges for anions was used to prepurify more than 24 acidic and alkaline
phytohormones from a single plant extract. The method showed good linearity for all 24 phytohormones with R2 values ranging from 0.9903 to 0.9997. Limits of detection for most of the phytohormones were in the femtomole range with
some extending into the sub-femtomole range. This method was applied to hundreds of plant samples comprising different tissues
from various plants, including herbaceous, woody climbing, and woody plants to demonstrate feasibility and to validate the
methodology.
Content Type Journal Article
Category Original Paper
Pages 1-10
DOI 10.1007/s00216-012-6509-2
Authors
Shichang Liu, College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083 China
Weiqi Chen, College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083 China
Long Qu, College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083 China
Ying Gai, College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083 China
Xiangning Jiang, College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083 China
A new high-performance liquid chromatographic method with triple quadrupole mass spectrometry detection was developed and
validated for the quantification of zopiclone enantiomers in rat brain samples. Zopiclone enantiomers were resolved on a CHIRALPAK
AD column with a mobile phase consisting of acetonitrile/ethanol/methanol (60:20:20, v/v/v) at a flow rate of 1.3 mL?min-1. Moclobemide was used as internal standard. The sample treatment procedure was carried out employing solid-phase extraction,
yielding mean absolute recoveries of 89.6 and 91.7 % for each zopiclone enantiomer. The validated method showed linearity
in the range of 0.29–344.8 ng?g?1, with quantification limits of 0.29 ng?g?1 for both enantiomers. Precision and accuracy were within acceptable levels of confidence (<15 %). The method was applied
in a pilot study of zopiclone kinetic disposition in rats. It could be observed that the levels of (+)-(S)-zopiclone were always higher than those of (-)-(R)-zopiclone, confirming the stereoselective disposition of zopiclone.
Content Type Journal Article
Category Original Paper
Pages 1-7
DOI 10.1007/s00216-012-6487-4
Authors
Milena Araújo Tonon, Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-903 SP, Brazil
Valquíria A. P. Jabor, Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-903 SP, Brazil
Pierina Sueli Bonato, Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-903 SP, Brazil
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