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1.
The analysis of synthetic polymers represents today an important part of polymer science to determine their physical properties and to optimize the performance of polymeric materials for block copolymers as well as blend systems. The characterization can easily and rapidly be performed by mass spectrometry. In particular, the film formation of a synthetic polymer is of interest in material research and quality control, which can be determined by employing mass spectrometric imaging (MSI) using secondary ion mass spectrometry (SIMS) or matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. MALDI-MSI has been rapidly improved for the analysis of tissue cross-sections due to its soft ionization and accessible m/z range, which both also play an important role in polymer science. On the other hand, SIMS-MSI enables a sub-micrometer molecular spatial resolution, which is limited in MALDI-MSI due to the spatial resolution capabilities of the laser desorption process. The aim of the present contribution is to summarize recent advances in both imaging techniques for the analysis of synthetic polymers and to highlight their capabilities to correlate several imaging modalities in future applications. 相似文献
2.
Detection of residual bacitracin A, colistin A, and colistin B in milk and animal tissues by liquid chromatography tandem mass spectrometry 总被引:3,自引:0,他引:3
Liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-MS/MS) was applied to the determination
of residual bacitracin A, colistin A, and colistin B in milk and animal tissue samples. Prior to instrumental analysis, samples
were subjected to acid extraction followed by solid-phase cleanup using Strata-X cartridges. Mass spectral acquisitions were
performed under selective multiple reaction monitoring (MRM) mode at m/z 199 and 670 from triply charged precursors of bacitracin A (m/z 475); m/z 385 and 379 from triply charged precursors of colistin A (m/z 391); and m/z 380 and 374 from triply charged precursors of colistin B (m/z 386). Method precision was evaluated from spike recovery of samples fortified at concentrations corresponding to 2/5 of the
maximum residue limits (MRLs) for each of the analytes under study. Intra-day and inter-day variations were found to range
from 90.9 to 104% with relative standard deviation (RSD) <6.5%, and from 90.1 to 106% with RSD <9.1%, respectively. Limits
of quantification (LOQs) were defined as the spiking concentrations at 2/5 MRL, and limits of detection (LODs) were 10–47 μg kg−1 for bacitracin A, 1–16 μg kg−1 for colistin A, and 6–14 μg kg−1 for colistin B in milk and animal tissues. The presented method has good precision and high sensitivity and was applied as
a fast screening protocol and a quantitative tool for monitoring of the concerned polypeptides in foods as part of a surveillance
program.
相似文献
3.
Bozena Winnik Dana B. Barr Mona Thiruchelvam M. Angela Montesano Eric K. Richfield Brian Buckley 《Analytical and bioanalytical chemistry》2009,395(1):195-201
Animal models, consistent with the hypothesis of direct interaction of paraquat (PQ) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP) with specific areas of the central nervous system have been developed to study Parkinson’s disease (PD) in mice. These
models have necessitated the creation of an analytical method for unambiguous identification and quantitation of PQ and structurally
similar MPTP and 1-methyl-4-phenylpyridinium ion (MPP+) in brain tissue. A method for determination of these compounds was developed using microwave-assisted solvent extraction
(MASE) and liquid chromatography–mass spectrometry. Extraction solvent and microwave conditions such as power and time were
optimized to produce recoveries of 90% for PQ 78% for MPTP and 97% for its metabolite MPP+. The chromatographic separation was performed on a C8, column and detection was carried out using an ion trap as an analyzer
with electrospray ionization. Mass spectrometer parameters such as heated capillary temperature, spray voltage, capillary
voltage and others were also optimized for each analyte. Analysis was done in selective ion-monitoring (SIM) mode using m/z 186 for PQ, m/z 174 for MPTP, and m/z 170 for MPP+. The method detection limit for paraquat in matrix was 100 pg, 40 pg for MPTP, and 20 pg MPP+. 相似文献
4.
This study presents a high-performance liquid chromatography–electrospray ionization–mass spectrometric (LC–ESI–MS) method
for the simultaneous determination of tramadol and acetaminophen in human plasma using phenacetinum as the internal standard.
After alkalization with saturated sodium bicarbonate, both compounds were extracted from human plasma with ethyl acetate and
were separated by HPLC on a Hanbon LiChrospher CN column with a mobile phase of 10 mM ammonium acetate buffer containing 0.5%
formic acid–methanol (40:60, v/v) at a flow rate of 1 mL min−1. Analytes were determined using electrospray ionization in a single quadrupole mass spectrometer. LC–ESI–MS was performed
in the positive selected-ion monitoring (SIM) mode using target ions at [M+H]+
m/z 264.3 for tramadol, [M+H]+
m/z 152.2 for acetaminophen and [M+H]+
m/z 180.2 for phenacetinum. Calibration curves were linear over the range of 5–600 ng mL−1 for tramadol and 0.03–16 μg mL−1 for acetaminophen. The inter-run relative standard deviations were less than 14.4% for tramadol and 12.3% for acetaminophen.
The intra-run relative standard deviations were less than 9.3% for tramadol and 7.9% for acetaminophen. The mean plasma extraction
recovery for tramadol and acetaminophen were in the ranges of 82.7–85.9 and 83.6–85.3%. The method was applied to study the
pharmacokinetics of a new formulation of tramadol/acetaminophen tablet in healthy Chinese volunteers. 相似文献
5.
H. P. de Oliveira J. Rieumont C. Nogueiras D. Souza R. Sánchez 《Journal of Thermal Analysis and Calorimetry》2011,103(2):443-451
The thermal degradation of an amphiphilic block copolymer poly(ethylene)-b-poly(ethylene oxide)-carboxylic acid terminated
(PE-b-80%PEO–CH2COOH) and its salt obtained as intermediary product from chemical oxidation of the end group of poly(ethylene)-b-poly(ethylene
oxide) (PE-b-80%PEO) has been studied using a thermogravimetric mass spectrometry (TG/MS) coupled system. The isothermal fragmentation
of PE-b-80%PEO–CH2COOH showed a more complex fragmentation pattern than PE-b-80%PEO owing to the simultaneous occurrence of the polyether block
and the carboxylic end group fragmentations. This led to the appearance of four overlapping ion current peaks of fragments
with m/z 44 and two peaks relative to m/z 18 at different times by acid-terminated copolymer. For the PE-b-80%PEO copolymer, two ion current peaks associated to m/z 44 and one large peak relative to m/z 18 fragments were detected. The intermediary product (PE-b-80%PEO–CH2COO− K+) showed differences related to the fragmentation behavior. It has more defined ion current signals and presented characteristic
peaks attributed to m/z 43 fragment at the very beginning of the thermal degradation process, which it not detected in the acid copolymer. 相似文献
6.
Vijaya D. Bharathi Kanbarpa Radharani Banda Jagadeesh Gajjela Ramulu Indu Bhushan Andra Naidu Ramesh Mullangi 《Chromatographia》2008,67(5-6):461-466
A rapid, sensitive, and simple HPLC–MS–MS method, with electro-spray ionization and cetirizine as internal standard (IS),
has been developed and validated for simultaneous quantification of fexofenadine and pseudoephedrine in human plasma. The
analytes were isolated from plasma by solid-phase extraction (SPE) on Oasis HLB cartridges. The compounds were chromatographed
on an RP 18 column with a mixture of ammonium acetate (10 mm, pH 6.4) and methanol as mobile phase. Quantification of the analytes was based on multiple reaction monitoring (MRM) of
precursor-to-product ion pairs m/z 502 → 466 for fexofenadine, m/z 166 → 148 for pseudoephedrine, and m/z 389 → 201 for cetirizine. The linear calibration range for both analytes was 2–1,700 ng mL−1 (r = 0.995), based on analysis of 0.1 mL plasma. Extraction recovery was 91.5 and 80.88% for fexofenadine and pseudoephedrine,
respectively. The method was suitable for analysis of human plasma samples obtained 72 h after administration of a drug containing
both fexofenadine and pseudoephedrine. 相似文献
7.
Nils Helge Schebb Helene Faber Ronald Maul Ferry Heus Jeroen Kool Hubertus Irth Uwe Karst 《Analytical and bioanalytical chemistry》2009,394(5):1361-1373
Abstract A novel method for the identification of glutathione/electrophile adducts that are inhibiting glutathione-S-transferase (GST) activity was developed and applied for the analysis of the mycotoxin patulin. The method is based on high-performance
liquid chromatography (HPLC) coupled to a continuous-flow enzyme reactor serving as biochemical detector (BCD) in parallel
to electrospray mass spectrometric detection (ESI-MS). This HPLC-BCD technique combines a separation step and the detection
of the inhibition and is therefore ideally suited for the analysis of the activity of single patulin/glutathione adducts within
a complex mixture of adducts. Two out of at least 15 detected patulin–glutathione adducts showed strong GST inhibition. In
ESI-MS, the inhibitory active adducts were characterized by [M + H]+ ions with m/z 462.1138 and m/z 741.2011, respectively. They could be identified as a dihydropyranone adduct containing one molecule glutathione and a ketohexanoic
acid bearing two glutathione molecules.
Graphical Abstract OnlineAbstractFigure
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
Inmaculada C. Fernández‐No Karola Böhme José M. Gallardo Jorge Barros‐Velázquez Benito Cañas Pilar Calo‐Mata 《Electrophoresis》2010,31(6):1116-1127
Histamine poisoning is caused by the consumption of fish and other foods that harbor bacteria possessing histidine decarboxylase activity. With the aim of preventing histamine formation, highly specific mass spectral fingerprints were obtained from the 16 major biogenic amine‐producing enteric and marine bacteria by means of MALDI‐TOF MS analysis. All bacterial strains analyzed exhibited specific spectral fingerprints that enabled its unambiguous differentiation. This technique also identified peaks common to certain bacterial groups. Thus, two protein peaks at m/z 4182±1 and 8363±6 were found to be present in all Enterobacteriaceae species analyzed except for Morganella morganii. Peaks at m/z 3635±1 and 7267±2 were specific to both M. morganii and Proteus spp. Biogenic amine‐forming Proteus spp. exhibited three genus‐specific peaks at m/z 3980, 7960±1 and 9584±2. The genus Photobacterium also showed three genus‐specific peaks at m/z 2980±1, 4275±1 and 6578±1. The two histamine‐producing Gram‐positive bacteria Lactobacillus sp. 30A and Staphylococcus xylosus exhibited a few protein peaks in the 2000–7000 m/z range and could be easily distinguished from biogenic amine‐forming Gram‐negative bacteria. Clustering based on MALDI‐TOF MS also exhibited a good correlation with phylogenetic analysis based on the 16S rRNA gene sequence, validating the ability of the MALDI‐TOF technique to establish relationships between microbial strains and species. The approach described in this study leads the way toward the rapid and specific identification of major biogenic amine‐forming bacteria based on molecular protein markers with a goal to the timely prevention of histamine food poisoning. 相似文献
9.
Ma Elena Alvarez-Pieiro Ma Josa Lpez De Alda-Villaizn Perfecto Paseiro-Losada Ma Asuncin Lage-Yusty 《Journal of separation science》1997,20(6):321-324
The recently developed tandem technique, mass spectroscopy with atmospheric-pressure chemical ionization (APCI-MS) coupled with direct flow injection, was applied to the determination of Bitrex (denatonium benzoate) and diethyl phthalate in ethanol. The compounds were indentified from their total-ion chromatograms(m/z 50-500) and, simultancously, quantified using selected-ion chromatograms recorded at m/z 223 for diethyl phthalate and m/z 325 for Bitrex. Operating conditions were optimized for soft ionization (positive ion-mode) with fragmentation limited to that necessary for analyte identification, which was by the external-standard method. Calibration curves were rectilinear in the concentration rages 2-30 μg ml?1 (Bitrex) and 0.075-1.2% v/v (diethyl phthalate); measurement precision (RSDs were 11.48% for Bitrex and 2.22% for diethyl phthalate), and detection limits (0.017 μg ml?1 and 0.010% v/v, respectively) were adequate for simiultaneous quantitation and with high sensitivity. The lack of any sample pretreatment and the use of flow-injection analysis meant that the procedure was moere straightforward and rapid than previously reported methods. 相似文献
10.
The amount of volatile dimethylselenide (DMSe) in breath has been monitored after ingestion of sub-toxic amounts of selenium
(300 μg 77Se, as selenite) by a healthy male volunteer. The breath samples were collected in Tedlar bags every hour in the first 12 h
and then at longer intervals for the next 10 days. The samples were subjected to speciation analysis for volatile selenium
compounds by use of cryotrapping–cryofocussing–GC–ICP–MS. Simultaneously, all urine was collected and subjected to total selenium
determination by use of ICP–MS. By monitoring m/z 82 and 77, background or dietary selenium and selenium from the administered selenite were simultaneously determined in the
urine and in the breath—dietary selenium only was measured by monitoring m/z 82 whereas the amount of spiked 77Se (99.1% [enriched spike]) and naturally occurring selenium (7.6% [natural abundance]) were measured by monitoring m/z 77. Quantification of DMSe was performed by using DMSe gas samples prepared in Tedlar bags (linear range 10–300 pg, R
2=0.996, detection limit of Se as DMSe was 10 pg Se, or 0.02 ng L−1, when 0.5 L gas was collected). Dimethylselenide was the only selenium species detected in breath samples before and after
the ingestion of 77Se-enriched selenite. Additional DM77Se was identified as early as 15 min after ingestion of the isotopically-labelled selenite. Although the maximum concentration
of 77Se in DMSe was recorded 90 min after ingestion, the natural isotope ratio for selenium in DMSe (77/82) was not reached after
20 days. The concentration of DMSe correlated with the total Se concentration in the urine during the experiment (R
2=0.80). Furthermore, the sub-toxic dose of 300 μg selenium led to a significant increase of DMSe and renal excretion of background
selenium, confirming that selenium ingested as selenite is homeostatically controlled by excretion. The maximum concentration
of DMSe resulting from the spiked selenite was 1.4 ng Se L−1 whereas the dietary background level was less than 0.4 ng Se L−1. Overall excretion as DMSe was calculated to be 11.2% from the ingested selenite within the first 10 days whereas urinary
excretion accounts for nearly 18.5%. 相似文献
11.
Dian-Lei Wang Yan Liang Lin Xie Tong Xie X. T. Wang Sen Yu Guang-Ji Wang Xiao-Dong Liu 《Chromatographia》2008,67(3-4):219-224
To evaluate the pharmacokinetics of a novel analogue of ginkgolide B, 10-O-dimethylaminoethylginkgolide B (XQ-1) in rat plasma in pre-clinical studies, a sensitive and specific liquid chromatographic
method with electrospray ionization mass spectrometry detection (LC–ESI–MS) was developed and validated. After a simple extraction
with ethyl acetate, XQ-1 was analyzed on a Shim-pack C18 column with a mobile phase of a mixture of 1 μmol L−1 ammonium acetate containing 0.02% formic acid and methanol (55:45, v/v) at a flowrate of 0.3 mL min−1. Detection was performed in selected ion monitoring (SIM) mode using target ions at [M + H]+
m/z 496.05 for XQ-1 and m/z 432.10 for the internal standard (lafutidine). Linearity was established for the concentration range from 2 to 1,000 ng mL−1 . The extraction recoveries ranged from 86.0 to 89.9% in plasma at concentrations of 5, 50, and 500 ng mL−1. The lower limit of quantification was 2 ng mL−1 with 100 μL plasma. The validated method was successfully applied to a pharmacokinetic study after intragastic administration
of XQ-1 mesylate in rats at a dose of 20 mg kg−1. 相似文献
12.
Jinmao You Yanyan Fu Zhiwei Sun Yourui Suo 《Analytical and bioanalytical chemistry》2010,396(7):2657-2666
2-(5-Benzoacridine)ethyl-p-toluenesulfonate (BAETS), a dual-sensitive probe, was reacted with bile acids in the presence of K2CO3 catalyst in dimethyl sulfoxide (DMSO) solvent to give BAETS–bile acid derivatives. Derivatives exhibited intense fluorescence
(FL) with an excitation maximum at λ
ex 270 nm and an emission maximum at λ
em 510 nm. MS analysis using APCI-MS indicated that derivatives had excellent APCI-MS ionizability with percentage ionization
δ values changing from 0 to 88.83% in aqueous acetonitrile and from 0 to 89.15% in aqueous methanol. The collision induced
dissociation spectra of m/z [M + H]+ contained specific fragment ions at m/z [M + H−H2O]+, [M + H−2H2O]+, [M + H−3H2O]+, 347.3, and 290.1. Repeatability was good for LC separation of BAETS–bile acid derivatives with aqueous acetonitrile as mobile
phase. The relative standard deviations (RSDs) of retention time and peak area at 6.6 nmol mL−1 levels with fluorescence detection (FL) were from 0.045 to 0.072% and from 2.16 to 2.73%, respectively. Excellent linear
responses were observed, with regression coefficients >0.9995. The FL detection limits (S/N = 3) were in the range of 18.0–36.1 fmol. The online APCI-MS detection limits are in the range of 500–790 fmol (at a signal-to-noise
ratio of 3). 相似文献
13.
Nare Alpheus Mautjana Donq Wen Looi John R. Eyler Anna Brajter‐Toth 《Electroanalysis》2010,22(1):79-89
High signal intensities of glutathione (GSH), [GSH+H]+ (m/z 308), cysteine (CySH), [CySH+H]+ (m/z 122), and homocysteine (hCySH), [hCySH+H]+ (m/z 136), are observed in ESI MS with on‐line electrochemistry (EC). Dimers formed by H‐bonding, which are not electrochemical products, are detected as [2GSH+H]+ (m/z 615), [2CySH+H]+ (m/z 243) and [2hCySH+H]+ (m/z 271) together with disulfide dimers GSSG, CySSCy and hCySSCyh, [GSSG+H]+ (m/z 613), [CySSCy+H]+ (m/z 241) and [hCySSCyh+H]+ (m/z 269). When dopamine is present a thiol/dopamine quinone (DAQ) adduct is observed. Formation of this adduct is proposed to occur by an electrochemical mechanism during ESI. Catalysis of thiol oxidation and analysis of thiol mixtures is addressed. 相似文献
14.
N-Methylaniline (NMA) was ethylated and N-ethylaniline (NEA) was methylated under chemical ionization conditions using C2H5I and CH3I, respectively, as reagent gases. The structures of the resulting m/z 136 adduct ions have been probed using metastable ion and collision-induced dissociation (CID) methods. From the similarity of the spectra obtained and from the presence of structure-diagnostic ions at m/z 59 (CH3NHC2H5+•) and m/z 44 (CH3NHCH2+), it is concluded that predominantly N-alkylation occurs in both systems. This interpretation was aided by the use of C2D5I and CD3I as reagents. Adduct ions of m/z 136 were also formed by ethylation of the isomeric toluidines and by methylation of the ring-ethylanilines. The resulting CID mass spectra were distinctly different from those obtained for the m/z 136 ions obtained by alkylation of NMA and NEA. Protonation of N-ethyl-N-methylaniline using CH3C(O)CH3 as Brønsted acid reagent produced an m/z 136 species whose CID mass spectrum also featured intense ion signals at m/z 59 and 44. This observation led to the conclusion that protonation with acetone as reagent results, in this case, in dominant N-protonation. However, the CID mass spectrum of the m/z 136 ion formed when CH3OH was the protonating agent featured a weak signal at m/z 44 and no signal at m/z 59. Hence it was concluded that the latter m/z 136 ion contains a larger contribution from the ring-protonated adduct. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
15.
This study concerns the development and validation of a complete method for the analysis of two highly reactive α-dicarbonyl
compounds, glyoxal (Gly) and methylglyoxal (Mgly), in atmospheric fine particulate matter (PM2.5). Method development included optimization of sample preparation procedures, e.g., filter extraction, concentration of extracts,
derivatization and solid-phase extraction (SPE) of derivatives, as well as reversed-phase liquid chromatography coupled to
electrospray ion-trap mass spectrometry (HPLC-ESI-IT/MS/MS) measurement parameters. Selectivity of detection was enhanced
using tandem mass spectrometric analysis in ESI positive ion mode via two multiple reaction monitoring channels, m/z 433 → m/z 250 and m/z 419 → m/z 236 for Mgly and Gly. Retention times were 9.5 and 12.5 min for Gly- and Mgly-bis-hydrazone derivatives. Calibration ranged
from 0.5 to 50 ng/mL. Inter-batch precision, expressed as relative standard deviation, was <15%. The method was shown to be
unaffected by the sample matrix and to have recoveries of 100% and 60% for Gly and Mgly, respectively. Improved instrumental
detection limits of 0.51 and 0.62 ng/mL for Gly and Mgly were achieved using a SPE method for the purification of 2,4-dinitrophenylhydrazine
derivatization reagent solutions. This permitted the method to be used for analysis of filter samples obtained during a field
study at the Taunus Observatory (mount Kleiner Feldberg, Germany). PM2.5 concentrations ranged from 0.81 to 1.18 ng/m3 for Gly and from 0.83 to 1.92 ng/m3 for Mgly. PM concentrations correlated to the concentration of NO with coefficients (R
2) of 0.67 (Gly) and 0.78 (Mgly). 相似文献
16.
如何筛选合理的数据库匹配结果对于基于质谱的蛋白质组学研究至关重要。但是目前,基于打分体系和反转数据库的筛选方法都无法有效的避免假阳性和假阴性匹配的存在。因此,本文提出了一种系统的搜索策略: 非同质荷比检索规则 (INMZS)。在该策略中,所有匹配结果都需要检查相关匹配质荷比的分享程度,只有那些相关质荷比均为专有匹配时,蛋白质才会被作为可信结果保留,策略还采用迭代搜索方法以提高鉴定低丰度组分的灵敏度。最终,所有的匹配结果由诱饵数据库方法进行评估以得到最终结果列表。INMZS策略在标准蛋白质混合物和大规模人肝蛋白质组数据上进行了模拟及应用,结果显示,INMZS规则和诱饵数据库评估方法的结和可以有效的保证蛋白质组学数据匹配的可信度及灵敏度,可以广泛适用于基于二维凝胶电泳及非shotgun技术的蛋白组学研究中。 相似文献
17.
Todd A. Lydic Julia V. Busik Walter J. Esselman Gavin E. Reid 《Analytical and bioanalytical chemistry》2009,394(1):267-275
A “shotgun” tandem mass spectrometry (MS) approach involving the use of multiple lipid-class-specific precursor ion and neutral
loss scan mode experiments has been employed to identify and characterize the glycerophosphatidylethanolamine (GPEtn) lipids
that were present within a crude lipid extract of a normal rat retina, obtained with minimal sample handling prior to analysis.
Characterization of these lipids was performed by complementary analysis of their protonated and deprotonated precursor ions,
as well as their various ionic adducts (e.g., Na+, Cl-), using a triple-quadrupole mass spectrometer. Notably, the application of novel precursor ion and neutral loss scans of
m/z 164 and m/z 43, respectively, for the specific identification of sodiated GPEtn precursor ions following the addition of 500 μM NaCl
to the crude lipid extracts was demonstrated. The use of these novel MS/MS scans in parallel provided simplified MS/MS spectra
and enhanced the detection of 1-alkenyl, 2-acyl (plasmenyl) GPEtn lipids relative to the positive ion mode neutral loss m/z 141 commonly used for GPEtn analysis. Furthermore, the novel use of a “low energy” neutral loss scan mode experiment to monitor
for the exclusive loss of 36m/z (HCl) from [M+Cl]- GPEtn adducts was demonstrated to provide a more than 25-fold enhancement for the detection of GPEtn lipids in negative ion
mode analysis. Subsequent “high-energy” pseudo MS3 product ion scans on the precursor ions identified from this experiment were then employed to rapidly characterize the fatty
acyl chain substituents of the GPEtn lipids.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
Gavin E. ReidEmail: |
18.
Li Kang Jinmao You Zhiwei Sun Chengyan Wang Zhongyin Ji Yongping Gao Yourui Suo Yulin Li 《Chromatographia》2011,73(1-2):43-50
A pre-column derivatization method for the simple, sensitive determination of biogenic amines using 10-ethyl-acridine-3-sulfonyl chloride (EASC) as labeling reagent with fluorescence detection and mass spectrometry (MS) identification has been developed. After pre-column derivatization, the labeled biogenic amines were separated on a Hypersil BDS-C18 column by gradient elution. The derivatives showed an intense protonated molecular ion corresponding m/z [M + H]+ in positive-ion mode. The collision-induced dissociation of protonated molecular ion formed specific fragment ions at m/z 196.5, m/z 222.7, m/z 224.4 and m/z 272.5, m/z 286.2. Satisfactory linear responses were observed at the concentration range of 0.02?C10 ??mol L?1 with coefficients of >0.9993. Detection limits obtained by the analysis of a derivatized standard containing 0.2 pmol of each biogenic amine, were from 20.22 to 109.2 fmol (at a signal-to-noise ratio of 3). The relative standard deviations of retention times and peak areas for each biogenic amine were <0.96 and 3.22%, respectively. Recoveries except for PUT were in the range of 96.7?C103.6% for chicken sausage and 95.8?C104.6% for pork sausage The established method for the determination of biogenic amines except for PUT from real samples was satisfactory. 相似文献
19.
Simultaneous determination of three dipeptides (JBP485, Gly–Sar and JBP923) in the cell lysates by liquid chromatography‐tandem mass spectrometry: application to identify the function of the PEPT1 transfected cell
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Xinjin Guo Qiang Meng Qi Liu Changyuan Wang Xiaokui Huo Zhe Zhang Taiichi Kaku Kexin Liu 《Biomedical chromatography : BMC》2014,28(12):1839-1845
A simple and rapid liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for the simultaneous determination of JBP485, Gly–Sar and JBP923 in the cell lysates using methanol as a deproteinization solvent was developed and validated. Detection was performed by turbo ionspray ionization in multiple reaction monitoring mode using the transitions of m/z 147.1 → m/z 90.1 for Gly–Sar, m/z 201.1 → m/z 86.1 for JBP485, m/z 219.1 → m/z 86.1 for JBP923 and m/z 152.0 → m/z 110.0 for paracetamol (internal standard). The analytes were separated on a Hypersil ODS C18 HPLC column using isocratic elution mode with a mobile phase containing 0.1% formic acid in water–methanol (97:3, v/v) at a flow rate of 0.2 mL/min. The calibration curves were demonstrated to be linear over the concentration range of 5.00?5000 nm with coefficient of 0.9968 for Gly–Sar, 0.9975 for JBP485 and 0.9952 for JBP923. The intra‐ and inter‐day precisions were <10.2% for each quality contro; level, and the accuracy was within ±5.6% for each analyte. The matrix effect, the extraction recovery and stabilities of LC‐MS/MS analysis were also investigated. This validated method was successfully applied to the simultaneous determination of JBP485, Gly–Sar and JBP923 in the cell lysates for identification of stably transfected HeLa cells with human PEPT1. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
20.
Jin‐Hee Park Yoo‐Sin Park Si‐Youn Rhim Hyun‐Jin Kim Ok‐Hwa Jhee Yun‐Sik Lee Min‐Ho Lee Leslie M. Shaw Ju‐Seop Kang 《Biomedical chromatography : BMC》2009,23(12):1350-1356
A rapid and validated method for analysis of levosulpiride in human plasma using liquid chromatography coupled to tandem mass spectrometry was developed. Levosulpiride and tiapride (IS, internal standard) were extracted from alkalized plasma samples with ethylacetate and separation by RP‐HPLC. Detection was performed by positive ion electrospray ionization in multiple‐reaction monitoring mode, monitoring the transitions m/z 342.1 → m/z 112.2 and m/z 329.1 → m/z 213.2, for quantification of levosulpiride and IS, respectively. The standard calibration curves showed good linearity within the range of 2–200 ng/mL (r2 ≥ 0.9990). The lower limit of quantitation was 2 ng/mL. The retention times of levosulpiride (0.63 min) and IS (0.66 min) presented a significant time saving benefit of the proposed method. No significant metabolic compounds were found to interfere with the analysis. This method offered good precision and accuracy and was successfully applied for the pharmacokinetic and bioequivalence study of a 25 mg of levosulpiride tablet in 24 healthy Korean volunteers. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献