共查询到20条相似文献,搜索用时 15 毫秒
1.
Barr DB Leng G Berger-Preiss E Hoppe HW Weerasekera G Gries W Gerling S Perez J Smith K Needham LL Angerer J 《Analytical and bioanalytical chemistry》2007,389(3):811-818
The objective of our study was to compare three vastly different analytical methods for measuring urinary metabolites of pyrethroid
and pyrethrum insecticides to determine whether they could produce comparable data and to determine if similar analytical
characteristics of the methods could be obtained by a secondary laboratory. This study was conducted as a part of a series
of validation studies undertaken by the German Research Foundation’s Committee on the Standardization of Analytical Methods
for Occupational and Environmental Medicine. We compared methods using different sample preparation methods (liquid–liquid
extraction and solid-phase extraction with and without chemical derivatization) and different analytical detection methods
(gas chromatography–mass spectrometry (single quadrupole), gas chromatography–high resolution mass spectrometry (magnetic
sector) in both electron impact ionization and negative chemical ionization modes, and high-performance liquid chromatography–tandem
mass spectrometry (triple quadrupole) with electrospray ionization). Our cross validation proved that similar analytical characteristics
could be obtained with any combination of sample preparation/analytical detection method and that all methods produced comparable
analytical results on unknown urine samples.
Cross-method comparison using unknown urine samples revealed reasonably good agreement for any combination of the methods
tested 相似文献
2.
Various toxicological and metabolic interactions have been reported to exist between arsenic and selenium. In the present
study, synthetic seleno-arsenic compounds, potentially suitable for probing metabolic interactions between these two elements,
were prepared and tentatively characterized by using high-performance liquid chromatography (HPLC)–electrospray tandem mass
spectrometry and HPLC–inductively coupled plasma mass spectrometry. In analogy to the recently identified thio-arsenic species,
which can be prepared from their corresponding oxo-arsenic species via reaction with H2S, the seleno-arsenic compounds were also derived from oxo-arsenic compounds via reaction with H2Se.
Figure H2Se bubbled into solutions containing oxo‐arsenosugars converts them into their seleno‐arsenosugar analogues. 相似文献
3.
Harir M Frommberger M Gaspar A Martens D Kettrup A El Azzouzi M Schmitt-Kopplin P 《Analytical and bioanalytical chemistry》2007,389(5):1459-1467
The photodecomposition of imazamox, a herbicide of the imidazolinone family, was investigated in pure water. The main photoproducts
from the photolysis were followed over time by liquid chromatography mass spectrometry and structures were proposed from exact
mass determinations obtained by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. The method
comprised exact mass determination with better than 0.2 ppm mass accuracy and a corresponding structural visualization taking
care of respective isotopes with an adapted van Krevelen diagram that enabled a systematic approach to the characterisation
of the elementary composition of each photoproduct. By taking advantage of the high resolving power of FT-ICR MS to make precise
formula assignments, the derived 2D van Krevelen diagram (O/C; H/C; m/z) enabled one to structurally differentiate the formed photoproducts and to propose a degradation pathway for imazamox.
Figure Overview of applied method to analyse the photolysis process of imazamox herbicide 相似文献
4.
Nattikarn Kaewkhomdee Sandra Mounicou Joanna Szpunar Ryszard Lobinski Juwadee Shiowatana 《Analytical and bioanalytical chemistry》2010,396(3):1355-1364
Sequential extraction (water, Driselase, protease XIV) and extraction with simulated gastric and intestinal fluids were proposed
to characterize the binding and the bioaccessibility of chromium in two commercial food supplements obtained by incorporation
of this element into yeast. Chromium in Cr-enriched yeast was found to be hardly extractable with water, Driselase, or simulated
gastric fluid (recoveries of approximately 10–20%), but proteolysis or gastrointestinal fluid digestion released more than
half of the chromium present. Fractionation with size-exclusion chromatography with Cr-specific detection by inductively coupled
plasma mass spectrometry (ICP MS) allowed the distinction of two fractions: one below approximately 1 kDa and one 1–5 kDa;
they contained the entirety of the released Cr with proportions varying as a function of the extracting solution and the origin
of sample. When collected and investigated by reversed-phase high-performance liquid chromatography–ICP MS, the low molecular
mass fraction was found to release Cr(III), whereas the heavier one showed most of Cr bound in fairly stable hydrophobic complexes.
However, an attempt of their identification by electrospray ionization MS/MS and matrix-assisted laser desorption ionization
MS was not successful.
相似文献
5.
Cuyckens F Balcaen LI De Wolf K De Samber B Van Looveren C Hurkmans R Vanhaecke F 《Analytical and bioanalytical chemistry》2008,390(7):1717-1729
A combination of inductively coupled plasma mass spectrometry (ICP-MS) and electrospray ionization mass spectrometry (ESI-MS)
was deployed for the metabolite profiling and metabolite identification of a new antituberculosis compound (R207910, also
known as TMC207) that is currently in drug development. R207910 contains one bromine atom, allowing the detection by ICP-MS.
Fluctuations in the Br sensitivity caused by the HPLC gradient were counteracted by the use of species-unspecific isotope
dilution. In order to evaluate the method developed, the results obtained were compared with those acquired via radioactivity
detection. HPLC-ESI-MS was used for the structural identification of R207910 and its metabolites. The 79Br/81Br isotope ratio is also valuable in the search for metabolites in the complex background of endogenous compounds obtained
using HPLC-ESI-MS analyses. Data-dependent scanning using isotope recognition with an ion trap mass spectrometer or processing
of Q-Tof data provides HPLC-ICP-MS-like “bromatograms”. The combination of accurate mass measurements and the fragmentation
behavior in the MS2 spectra obtained using the Q-Tof Ultima mass spectrometer or MSn spectra acquired using the LTQ-Orbitrap allowed structural characterization of the main metabolites of R207910 in methanolic
dog and rat faeces extracts taken 0–24 h post-dose.
Figure Analyses of a rat faeces extract taken 0–24 h post-dose: a HPLC-ICP-MS using isotope dilution, b corresponding Br mass flow chromatogram, c radio-HPLC, d Q-Tof ESI-MS TIC, e Q-Tof ESI-MS bromatogram after Br stripping, f LTQ-Orbitrap ESI-MS2 TIC obtained with isotopic-data-dependent scanning 相似文献
6.
Francis Canon Franck Paté Emmanuelle Meudec Thérèse Marlin Véronique Cheynier Alexandre Giuliani Pascale Sarni-Manchado 《Analytical and bioanalytical chemistry》2009,395(8):2535-2545
Numerous protein–polyphenol interactions occur in biological and food domains particularly involving proline-rich proteins,
which are representative of the intrinsically unstructured protein group (IUP). Noncovalent protein–ligand complexes are readily
detected by electrospray ionization mass spectrometry (ESI-MS), which also gives access to ligand binding stoichiometry. Surprisingly,
the study of interactions between polyphenolic molecules and proteins is still an area where ESI-MS has poorly benefited,
whereas it has been extensively applied to the detection of noncovalent complexes. Electrospray ionization mass spectrometry
has been applied to the detection and the characterization of the complexes formed between tannins and a human salivary proline-rich
protein (PRP), namely IB5. The study of the complex stability was achieved by low-energy collision-induced dissociation (CID)
measurements, which are commonly implemented using triple quadrupole, hybrid quadrupole time-of-flight, or ion trap instruments.
Complexes composed of IB5 bound to a model polyphenol EgCG have been detected by ESI-MS and further analyzed by MS/MS. Mild
ESI interface conditions allowed us to observe intact noncovalent PRP–tannin complexes with stoichiometries ranging from 1:1
to 1:5. Thus, ESI-MS shows its efficiency for (1) the study of PRP–tannin interactions, (2) the determination of stoichiometry,
and (3) the study of complex stability. We were able to establish unambiguously both their stoichiometries and their overall
subunit architecture via tandem mass spectrometry and solution disruption experiments. Our results prove that IB5·EgCG complexes
are maintained intact in the gas phase.
相似文献
7.
4,4′-methylenedianiline (DAPM) is the main building block for production of 4,4′-methylenediphenyldiisocyanate that has been
widely used in the manufacturing of polyurethane materials including medical devices. Although it was revealed that damage
to biliary epithelial cells of the liver and common bile duct occurred upon acute exposure to DAPM, the exact mechanism of
DAPM toxicity is not fully understood. Both phase I and II biotransformations of DAPM, some of which generate reactive intermediates,
are characterized in detail by liquid chromatography electrospray tandem mass spectrometry. The two most prominent metabolites
found in rat bile (M2 and M7) implicated glutathione, glucuronic acid, and glycine conjugations (phase II) following hydroxylation,
and N-oxidation (phase I). Their decomposition pathways, as evidenced by MS
n
experiments, have been elucidated in detail.
Figure Proposed fragmentation pathways of a DAPM metabolite 相似文献
8.
Pyochelin is a siderophore and virulence factor common to Burkholderia cepacia and several Pseudomonas strains. It is isolated from bacterial media as a mixture of two epimers, which readily equilibrate in most solvents. Experiments based on high-performance liquid chromatography/electrospray ionization mass spectrometry are reported here, allowing the investigation of the different Fe(III)-chelating properties of pyochelin diastereomers in solution without the need for labourious isolation. It is demonstrated in this study that only one of the two pyochelin diastereomers is able to chelate Fe(III); no Fe(III) complexes of the other diastereomer could be detected. The Fe(III)–pyochelin complex exhibited a 1:1 metal-to-siderophore ratio and no evidence for other stoichiometries was found.
相似文献
9.
Liquid chromatography/mass spectrometric analysis of rat samples for in vivo metabolism and pharmacokinetic studies of ginsenoside Rh2 总被引:2,自引:0,他引:2
Qian T Cai Z Wong RN Jiang ZH 《Rapid communications in mass spectrometry : RCM》2005,19(23):3549-3554
In vivo metabolism and pharmacokinetic studies on rat were conducted for ginsenoside Rh2, one of the components from ginseng that shows promise of anticancer activity. Liquid chromatography/mass spectrometry (LC/MS) and tandem mass spectrometry (MS/MS) with electrospray ionization were used to determine Rh2 and its metabolites in rat plasma, urine and feces. An average half-life of 16 min in plasma was obtained after intravenous administration to male Sprague-Dawley rats at 5 mg/kg. No Rh2 was detected in plasma samples collected from 0 to 24 h following oral administration at 100 mg/kg, and only 0.12-0.25% of the dosed amount was found in the feces samples collected from 0 to 48 h after oral administration at 100 mg/kg. Three metabolites of Rh2 were detected in the feces samples. Oxygenation and deglycosylation were found to be the major metabolic pathways of Rh2. Intense metabolism, rather than excretion, appears to be the reason for the fast clearance of this ginsenoside. 相似文献
10.
Bai LP Cai Z Zhao ZZ Nakatani K Jiang ZH 《Analytical and bioanalytical chemistry》2008,392(4):709-716
Spectrofluorometric titration, electrospray ionization time-of-flight mass spectrometric and UV melting methods were employed
to study the binding of chelerythrine and sanguinarine to bulged DNA. The results showed that both alkaloids bind specifically
to single pyrimidine (C, T) bulge sites. The ability of sanguinarine to bind to both regular and bulged hairpins was found
to be stronger than that of chelerythrine, but the binding selectivity of chelerythrine toward single-base bulges was much
larger than that of sanguinarine.
Figure Association constants for chelerythrine and sanguinarine toward regular and single-base bulged hairpins obtained from fluorometric
analysis 相似文献
11.
Bo Yan Zheng-Jiang Zhu Oscar R. Miranda Apiwat Chompoosor Vincent M. Rotello Richard W. Vachet 《Analytical and bioanalytical chemistry》2010,396(3):1025-1035
Monolayer-protected gold nanoparticles (AuNPs) feature unique surface properties that enable numerous applications. Thus,
there is a need for simple, rapid, and accurate methods to confirm the surface structures of these materials. Here, we describe
how laser desorption/ionization mass spectrometry (LDI-MS) can be used to characterize AuNPs with neutral, positively, and
negatively charged surface functional groups. LDI readily desorbs and ionizes the gold-bound ligands to produce both free
thiols and disulfide ions in pure and complex samples. We also find that LDI-MS can provide a semi-quantitative measure of
the ligand composition of mixed-monolayer AuNPs by monitoring mixed disulfide ions that are formed. Overall, the LDI-MS approach
requires very little sample, provides an accurate measure of the surface ligands, and can be used to monitor AuNPs in complex
mixtures.
相似文献
12.
Fanny Kieken Gaud Pinel Jean-Philippe Antignac Fabrice Monteau Anne Christelle Paris Marie-Agnès Popot Yves Bonnaire Bruno Le Bizec 《Analytical and bioanalytical chemistry》2009,394(8):2119-2128
Despite the worldwide existing regulation banning the use of the recombinant equine growth hormone (reGH) as growth promoter,
it is suspected to be used in horseracing to improve performances. Various analytical methods previously developed to screen
for its misuse have encountered some limitations in terms of detection timeframes, in particular during the first days following
reGH administration. A novel strategy involving the characterization of global metabolomic fingerprints in urine samples of
non-treated and reGH-treated horses by liquid chromatography–electrospray–high-resolution mass spectrometry (LC-ESI-HRMS)
is described and assessed in this paper in order to develop a new screening tool for growth hormone abuse in horseracing.
The strategy involves a limited sample preparation of the urine samples and the use of appropriate software for data processing
and analysis. As preliminary work, reproducibility of both sample preparation and mass spectrometry (MS) measurements was
evaluated in order to demonstrate the reliability of the method. Application of the developed protocol on two horses demonstrated
the suitability of the developed strategy and preliminary results showed significant modifications of the metabolome after
treatment with reGH.
相似文献
13.
Surmeian A Diplasu C Groza A Ganciu M Belenguer P Tempez A Chapon P 《Analytical and bioanalytical chemistry》2007,388(8):1625-1629
A high-current pulsed hollow cathode discharge was used to study the role of atomic and ionic metastables involved in ionization
plasma processes. We observed the enhancement of the spectral emission lines of noble gas ions in the afterglow. A study of
the processes that involve atomic and ionic metastables is of great interest since it should lead to a better understanding
of and enhanced control over the ionization mechanisms crucial to analytical glow discharge mass spectrometry (GDMS) analysis.
Figure Time profile of Ti, Ti+, and Ne+ spectral lines 相似文献
14.
Raczyńska ED Gal JF Maria PC Zientara K Szelag M 《Analytical and bioanalytical chemistry》2007,389(5):1365-1380
Fourier transform ion cyclotron resonance mass spectrometry, combined with modern ionization (fast atom bombardment , electrospray
ionization, matrix-assisted laser desorption–ionization), fragmentation (collision-induced dissociation, surface-induced dissociation,
one-photon ultraviolet photodissociation, infrared multiphoton dissociation, blackbody infrared radiative dissociation, electron-capture
dissociation), and separation (high-performance liquid chromatography, liquid chromatography, capillary electrophoresis) techniques
is now becoming one of the most attractive and frequently used instrumental platforms for gas-phase studies of biomolecules
such as amino acids, bioamines, peptides, polypeptides, proteins, nucleobases, nucleosides, nucleotides, polynucleotides,
nucleic acids, saccharides, polysaccharides, etc. Since it gives the possibilities to trap the ions from a few seconds up
to thousands of seconds, it is often applied to study ion/molecule reactions in the gas phase, particularly proton-transfer
reactions which provide important information on acid–base properties. These properties determine in part the three-dimensional
structure of biomolecules, most of their intramolecular and intermolecular interactions, and consequently their biological
activity. They also indicate the form (unionized, zwitterionic, protonated, or deprotonated) which the biomolecule may take
in a nonpolar environment.
Figure Biomolecules in the gas-phase acidity-basicity scale 相似文献
15.
Hye Kyeong Min Gu Kong Myeong Hee Moon 《Analytical and bioanalytical chemistry》2010,396(3):1273-1280
Analysis was performed on four different categories of phospholipids (phosphatidylserine (PS), phosphatidylinositol (PI),
phosphatidylglycerol (PG), and phosphatidic acid (PA)) from urine in patients with breast cancer. This quantitative analysis
was conducted using nanoflow liquid chromatography–electrospray ionization–tandem mass spectrometry (nLC-ESI-MS-MS). This
study shows the profiling of the phospholipids (PLs) that can be identified by the negative ion mode of MS. A previous study
(Kim et al. Anal. Bioanal. Chem. 393:1649, 21) focused on only two PL classes: phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) and were identified by positive
ion mode. PLs were extracted by lyophilization of 1 mL of urine from both healthy normal females and breast cancer patients
before and after surgery. Separation of PLs was performed by nLC followed by structural identification of PLs using data-dependent
collision-induced dissociation. A total of 34 urinary PL molecules (12 PSs, 12 PIs, four PGs, and six PAs) were quantitatively
examined. Among the four PL categories examined in this study, most PL classes showed an increase in the total amounts in
the cancer patients, yet PIs exhibited some decreases. The present study suggests that the lipid composition found in the
urine of breast cancer patients can be utilized for the possible development of disease markers, when the analysis is performed
with negative ion mode of nLC-ESI-MS-MS.
相似文献
16.
Glutathione peroxidase (isolated from bovine erythrocytes) and its behaviour during alkylation and enzymatic digestion were
studied by various hyphenated techniques: gel electrophoresis–laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry
(MS), size-exclusion liquid chromatography–ICP MS, capillary high-performance liquid chromatography (capHPLC)–ICP MS, matrix-assisted
laser desorption/ionization (MALDI) time-of-flight (TOF) MS, electrospray MS, and nanoHPLC–electrospray ionization (ESI) MS/MS.
ESI TOF MS and MALDI TOF MS allowed the determination of the molecular mass but could not confirm the presence of selenium
in the protein. The purity of the protein with respect to selenium species could be evaluated by LA ICP MS and size-exclusion
chromatography (SEC)–ICP MS under denaturating and nondenaturating conditions, respectively. SEC–ICP MS and capHPLC–ICP MS
turned out to be valuable techniques to study the enzymolysis efficiency, miscleavage and artefact formation during derivatization
and tryptic digestion. For the first time the parallel ICP MS and ESI MS/MS data are reported for the selenocysteine-containing
peptide extracted from the gel; capHPLC–ICP MS allowed the sensitive detection of the selenopeptide regardless of the matrix
and nanoHPLC–electrospray made possible its identification.
Figure Eye catching image
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Christian Zwiener Thomas Glauner Jochen Sturm Michael W?rner Fritz H. Frimmel 《Analytical and bioanalytical chemistry》2009,395(6):1885-1892
Potentiostatic-controlled electrochemical reduction of iomeprol was used to deiodinate iomeprol (IMP), a representative of
the iodinated X-ray contrast media. The reduction process was followed by product analysis with liquid chromatography-electrospray
ionization-tandem mass spectrometry and ion chromatography-inductively coupled plasma-mass spectrometry. The identification
is mainly based on the interpretation of the mass fragmentation. The product analysis showed a rather selective deiodination
process with the successive occurrence of IMP-I, IMP-2I, IMP-3I, and a transformation product (TP), respectively. The TP was
formed from IMP-3I by a further cleavage of an amide bond and release of a (C = O)CHOH group from the side chain of IMP. The
iodine mass balance on the basis of IMP and iodide showed a gap of about 26% at the beginning of the electrolysis process
which could be completely closed by taking the intermediates IMP-I and IMP-2I into consideration. This means that the major
intermediates and the TPs were considered and that the reduction process is a rather selective one to remove organically bound
iodine from X-ray contrast media. An attractive application area would be the electrochemical deiodination of X-ray contrast
media in urine of patients or hospital effluents.
相似文献
18.
Maurer HH 《Analytical and bioanalytical chemistry》2007,388(7):1315-1325
This paper reviews multi-analyte single-stage and tandem liquid chromatography–mass spectrometry (LC-MS) procedures using
different mass analyzers (quadrupole, ion trap, time-of-flight) for screening, identification, and/or quantification of drugs,
poisons, and/or their metabolites in blood, plasma, serum, or urine published after 2004. Basic information about the biosample
assayed, work-up, LC column, mobile phase, ionization type, mass spectral detection mode, and validation data of each procedure
is summarized in tables. The following analytes are covered: drugs of abuse, analgesics, opioids, sedative-hypnotics, benzodiazepines,
antidepressants including selective-serotonin reuptake inhibitors (SSRIs), herbal phenalkylamines (ephedrines), oral antidiabetics,
antiarrhythmics and other cardiovascular drugs, antiretroviral drugs, toxic alkaloids, quaternary ammonium drugs and herbicides,
and dialkylphosphate pesticides. The pros and cons of the reviewed procedures are critically discussed, particularly, the
need for studies on matrix effects, selectivity, analyte stability, and the use of stable-isotope labeled internal standards
instead of unlabeled therapeutic drugs. In conclusion, LC-MS will probably become a gold standard for detection of very low
concentrations particularly in alternative matrices and for quantification in clinical and forensic toxicology. However, some
drawbacks still need to be addressed and finally overcome.
Photos of LC-MS apparatus and typical samples suitable for toxicological analysis 相似文献
19.
Covalent adduction of the model protein apomyoglobin by 4-hydroxy-2-nonenal, a reactive end-product of lipid peroxidation,
was characterized by nanoelectrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FTICR). The
high mass resolving power and mass measurement accuracy of the instrument facilitated a detailed compositional analysis of
the complex reaction product without the need for deconvolution and transformation to clearly show the pattern of adduction
and component molecular weights. Our study has also demonstrated the value of electron capture dissociation over collision-induced
dissociation for the tandem mass spectrometric determination of site modification for the 4-hydroxy-2-nonenal adduct of oxidized
insulin B chain as an example.
Figure FTICR allowed characterization of 4-hydroxy-2-nonenal (HNE)-modified apomyoglobin (an expanded spectrum of the +15 charge
state is shown) 相似文献
20.
Sergi M Bafile E Compagnone D Curini R D'Ascenzo G Romolo FS 《Analytical and bioanalytical chemistry》2009,393(2):709-718
An analytical procedure for the simultaneous determination in human plasma and oral fluids of several illicit drugs belonging
to different chemical and toxicological classes is presented. Amphetamine, methamphetamine, morphine, 6-monoacetylmorphine,
methylenedioxyamphetamine, methylenedioxyethylamphetamine, methylenedioxymethamphetamine, cocaine, benzoylecgonine, tetrahydrocannabinol,
carboxytetrahydrocannabinol, ketamine, and phencyclidine have been quantified in real samples using a very rapid sample treatment,
basically a protein precipitation. The quantitative analysis was performed by liquid chromatography–tandem mass spectrometry
and has been fully validated. All the analytes were detected in positive ionization mode using a TurboIonSpray source, except
carboxytetrahydrocannabinol, which was detected in negative ionization mode. The use of a diverter valve between the column
and the mass spectrometer allows the preservation of the ion source performances for high-throughput analysis.
Figure Diverter system 相似文献