共查询到20条相似文献,搜索用时 9 毫秒
1.
Gika HG Theodoridis G Extance J Edge AM Wilson ID 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2008,871(2):279-287
The applicability and potential of using elevated temperatures and sub 2-microm porous particles in chromatography for metabonomics/metabolomics was investigated using, for the first time, solvent temperatures higher than the boiling point of water (up to 180 degrees C) and thermal gradients to reduce the use of organic solvents. Ultra performance liquid chromatography, combined with mass spectrometry, was investigated for the global metabolite profiling of the plasma and urine of normal and Zucker (fa/fa) obese rats (a well established disease animal model). "Isobaric" high temperature chromatography, where the temperature and flow rate follow a gradient program, was developed and evaluated against a conventional organic solvent gradient. LC-MS data were first examined by established chromatographic criteria in order to evaluate the chromatographic performance and next were treated by special peak picking algorithms to allow the application of multivariate statistics. These studies showed that, for urine (but not plasma), chromatography at elevated temperatures provided better results than conventional reversed-phase LC with higher peak capacity and better peak asymmetry. From a systems biology point of view, better group clustering and separation was obtained with a larger number of variables of high importance when using high temperature-ultra performance liquid chromatography (HT-UPLC) compared to conventional solvent gradients. 相似文献
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Bethanne M. Warrack Serhiy Hnatyshyn Karl-Heinz Ott Michael D. Reily Mark Sanders Haiying Zhang Dieter M. Drexler 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2009,877(5-6):547-552
Unlike plasma and most biological fluids which have solute concentrations that are tightly controlled, urine volume can vary widely based upon water consumption and other physiological factors. As a result, the concentrations of endogenous metabolites in urine vary widely and normalizing for these effects is necessary. Normalization approaches that utilized urine volume, osmolality, creatinine concentration, and components that are common to all samples (“total useful MS signal”) were compared in order to determine which strategies could be successfully used to differentiate between dose groups based upon the complete endogenous metabolite profile. Variability observed in LC/MS results obtained from targeted and non-targeted metabonomic analyses was highly dependent on the strategy used for normalization. We therefore recommend the use of two different normalization techniques in order to facilitate detection of statistically significant changes in the endogenous metabolite profile when working with urine samples. 相似文献
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Elizabeth Hamelin Leigh Swaim Jerry Thomas Robert Kobelski Rudolph C. Johnson 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(27):2541-2547
Tetramethylene disulfotetramine (tetramine) is a rodenticide associated with numerous poisonings was extracted and quantified in human urine using both gas chromatography/mass spectrometry (GC/MS) and GC/tandem mass spectrometry (MS/MS). 1200 μL samples were prepared using a 13C4-labeled internal standard, a 96-well format, and a polydivinyl-benzene solid phase extraction sorbent bed. Relative extraction recovery was greater than 80% at 100 ng/mL. Following extraction, samples were preconcentrated by evaporation at 60 °C, and reconstituted in 50 μL acetonitrile. One-microliter was injected in a splitless mode on both instruments similarly equipped with 30 m × 0.25 mm × 25 μm, 5% phenyl-methylpolysiloxane gas chromatography columns. A quantification ion and a confirmation ion (GC/MS) or analogous selected reaction monitoring transitions (GC/MS/MS) were integrated for all reported results. The method was characterized for precision (5.92–13.4%) and accuracy (96.4–111%) using tetramine-enriched human urine pools between 5 and 250 ng/mL. The method limit of detection was calculated to be 2.34 and 3.87 ng/mL for GC/MS and GC/MS/MS, respectively. A reference range of 100 unexposed human urine samples was analyzed for potential endogenous interferences on both instruments—none were detected. Based on previous literature values for tetramine poisonings, this urinary method should be suitable for measuring low, moderate, and severe tetramine exposures. 相似文献
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Capsidiol, solavetivone, 3-hydroxysolavetivone, 3-hydroxylubimin, rishitin, epirishitin, glutinosone and oxyglutinosone were isolated from TMV-inoculat 相似文献
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Wong MC Lee WT Wong JS Frost G Lodge J 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2008,871(2):341-348
The application of LC-MS for untargeted urinary metabolite profiling in metabonomic research has gained much interest in recent years. However, the effects of varying sample pre-treatments and LC conditions on generic metabolite profiling have not been studied. We aimed to evaluate the effects of varying experimental conditions on data acquisition in untargeted urinary metabolite profiling using UPLC/QToF MS. In-house QC sample clustering was used to monitor the performance of the analytical platform. In terms of sample pre-treatment, results showed that untreated filtered urine yielded the highest number of features but dilution with methanol provided a more homogenous urinary metabolic profile with less variation in number of features and feature intensities. An increased cycle time with a lower flow rate (400mul/min vs 600mul/min) also resulted in a higher number of features with less variability. The step elution gradient yielded the highest number of features and the best chromatographic resolution among three different elution gradients tested. The maximum retention time and mass shift were only 0.03min and 0.0015Da respectively over 600 injections. The analytical platform also showed excellent robustness as evident by tight QC sample clustering. To conclude, we have investigated LC conditions by studying variability and repeatability of LC-MS data for untargeted urinary metabolite profiling. 相似文献
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Within-day reproducibility of an HPLC-MS-based method for metabonomic analysis: application to human urine 总被引:3,自引:0,他引:3
Self-evidently, research in areas supporting "systems biology" such as genomics, proteomics, and metabonomics are critically dependent on the generation of sound analytical data. Metabolic phenotyping using LC-MS-based methods is currently at a relatively early stage of development, and approaches to ensure data quality are still developing. As part of studies on the application of LC-MS in metabonomics, the within-day reproducibility of LC-MS, with both positive and negative electrospray ionization (ESI), has been investigated using a standard "quality control" (QC) sample. The results showed that the first few injections on the system were not representative, and should be discarded, and that reproducibility was critically dependent on signal intensity. On the basis of these findings, an analytical protocol for the metabonomic analysis of human urine has been developed with proposed acceptance criteria based on a step-by-step assessment of the data. Short-term sample stability for human urine was also assessed. Samples were stable for at least 20 h at 4 degrees C in the autosampler while queuing for analysis. Samples stored at either -20 or -80 degrees C for up to 1 month were indistinguishable on subsequent LC-MS analysis. Overall, by careful monitoring of the QC data, it is possible to demonstrate that the "within-day" reproducibility of LC-MS is sufficient to ensure data quality in global metabolic profiling applications. 相似文献
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Sabine Blechschmidt Ute Castel Paul Gaskin Peter Hedden Jan E. Graebe Jake MacMillan 《Phytochemistry》1984,23(3):553-558
The GC/MS detection is reported of over 30 compounds, in extracts of the endosperm and embryos from seeds of Cucurbita maxima. The compounds which were identified from reference spectra include: cis,trans-ABA; trans,trans-ABA; dihydrophaseic acid; IAA; GA4; GA12; GA13; GA25; GA39; GA43; GA49; ent-13-hydroxy-, ent-6α,7α-and ent-7α,13-dihydroxy-, and ent-6α,7α,13-trihydroxykaur-16-en-19-oic acids; ent-7α,16,17-trihydroxy- and ent-6α,7α,16,17-tetrahydroxy-kauran-19-oic acids, ent-6,7-seco-7-oxokauren-6,19-dioic acid and/or ent-6,7-secokauren-6,7,19-trioic acid, and 7β,12α-dihydroxykaurenolide. New compounds, the structures of which were deduced from GC/MS data, include: the 12α-hydroxy-derivatives of GA12, GA14, GA37 and GA4, and the 12β-hydroxy-derivatives of ent-7α-hydroxy- and ent-6α,7α-dihydroxykaurenoic acids. 相似文献
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Mitova M Taskova R Popov S Berger RG Krings U Handjieva N 《Zeitschrift für Naturforschung. C, Journal of biosciences》2003,58(9-10):697-703
Sterols, triterpenes, volatiles, polar and other constituents in aerial parts of Carthamus lanatus were analyzed by gas chromatography-mass spectrometry. Over 90 compounds were identified most of them new for the species. Sitosterol and stigmasterol were the most abundant of 10 sterols identified in the sterol fraction. Taraxasterol, alpha- and beta-amyrine prevailed in the triterpene fraction. Volatiles, sterols and a fraction of the dichloromethane extract showed strong cytotoxicity (Artemia salina assay). 相似文献
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Ciner FL McCord CE Plunkett RW Martin MF Croley TR 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,846(1-2):42-50
Organophosphorus nerve agents (OPNA), chemically related to and derived from organophosphate insecticides, constitute a clear and present threat to both military and civilian targets. Military regimes and terrorist organizations have demonstrated the will and ability to produce mass casualties by dispersing organophosphorus nerve agents, which, in turn could terrorize populations and overwhelm healthcare systems. A high throughput, robust and sensitive analytical protocol has been developed for the quantitation of the urinary metabolites of sarin (GB), soman (GD), VX, Russian VX (RVX) and cyclohexylsarin (GF) utilizing solid phase extraction (SPE) followed by High Performance Liquid Chromatography (HPLC)-isotope dilution tandem mass spectrometry (LC/MS/MS). The method has demonstrated linearity and reproducibility (1-200 ng/mL) for all analytes and has a Limit of Quantitation (LOQ)< or =0.5 ng/mL for all analytes (S/N> or =10/1). The method was validated by performing 20 individual analyses over 10 days by five scientists with all values falling within two standard deviations of the mean. 相似文献
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Wang D Hang T Wu C Liu W 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,829(1-2):97-106
To identify the major metabolites of resveratrol in rat, rat urine samples were pretreated by using solid-phase extraction technique (SPE) with polyamide cartridges. And a LC-MS/MS method with electrospray ionisation (ESI), negative ion mode and collision induced dissociation (CID), was used to elucidate the structures of the major metabolites of resveratrol. According to the results of our experiment, we found that the main metabolites of resveratrol were resveratrol monoglucuronide (M1), dihydroresveratrol monosulfate (M2), resveratrol monosulfate (M3) and dihydroresveratrol (M4). 相似文献
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Stereoselective analysis of bupropion and hydroxybupropion in human plasma and urine by LC/MS/MS 总被引:2,自引:0,他引:2
Coles R Kharasch ED 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,857(1):67-75
A sensitive, stereoselective assay using solid phase extraction and LC-MS-MS was developed and validated for the analysis of (R)- and (S)-bupropion and its major metabolite (R,R)- and (S,S)-hydroxybupropion in human plasma and urine. Plasma or glucuronidase-hydrolyzed urine was acidified, then extracted using a Waters Oasis MCX solid phase 96-well plate. HPLC separation used an alpha(1)-acid glycoprotein column, a gradient mobile phase of methanol and aqueous ammonium formate, and analytes were detected by electrospray ionization and multiple reaction monitoring with an API 4000 Qtrap. The assay was linear in plasma from 0.5 to 200 ng/ml and 2.5 to 1000 ng/ml in each bupropion and hydroxybupropion enantiomer, respectively. The assay was linear in urine from 5 to 2000 ng/ml and 25 to 10,000 ng/ml in each bupropion and hydroxybupropion enantiomer, respectively. Intra- and inter-day accuracy was >98% and intra- and inter-day coefficients of variations were less than 10% for all analytes and concentrations. The assay was applied to a subject dosed with racemic bupropion. The predominant enantiomers in both urine and plasma were (R)-bupropion and (R,R)-hydroxybupropion. This is the first LC-MS/MS assay to analyze the enantiomers of both bupropion and hydroxybupropion in plasma and urine. 相似文献
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Alexander A. Zoerner Karsten Heusser Frank M. Gutzki Anja Mitschke Jens Tank Dirk O. Stichtenoth Jens Jordan Dimitrios Tsikas 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(17-18):1444-1456
In the human body, the catecholamine norepinephrine is mainly metabolized to 3,4-dihydroxyphenylglycol (DHPG) which therefore serves as an important biomarker for norepinephrine's metabolism. Most data on DHPG concentrations in human plasma and urine has been generated by using HPLC-ECD or GC–MS technologies. Here, we describe a stable-isotope dilution GC–MS/MS method for the quantitative determination of DHPG in human urine using trideutero-DHPG (d3-DHPG) as internal standard and a two-step derivatization process with pentafluorobenzyl bromide (PFB-Br) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). Two pentafluorobenzyl (PFB) trimethylsilyl (TMS) derivatives were obtained and identified, i.e., two isomeric DHPG-PFB-(TMS)3 derivatives and the later eluting DHPG-tetrafluorobenzyl-(TMS)2 derivative, i.e., DHPG-TFB-(TMS)2. To our knowledge the DHPG-TFB-(TMS)2 derivative and the underlying reaction have not been reported previously. In this reaction both vicinal aromatic hydroxyl groups of DHPG react with PFB-Br to form a heterocyclic seven-membered [1,4]dioxepin compound. The DHPG-TFB-(TMS)2 derivative was used for quantitative GC–MS/MS analysis in the electron-capturing negative-ion chemical ionization mode by selected-reaction monitoring of m/z 351 from m/z 401 for DHPG and of m/z 352 from m/z 404 for d3-DHPG. Validation experiments on human urine samples spiked with DHPG in a narrow (0–33 nM) and a wide range (0–901 nM) revealed high recovery (86–104%) and low imprecision (RSD; 0.01–2.8%). LOD and relative LLOQ (rLLOQ) values of the method for DHPG were determined to be 76 amol and 9.4%, respectively. In urine of 28 patients suffering from chronic inflammatory rheumatic diseases, DHPG was measured at a mean concentration of 238 nM (38.3 μg/g creatinine). The DHPG concentration in the respective control group of 40 healthy subjects was measured to be 328 nM (39.2 μg/g creatinine). Given the unique derivatization reaction and collision-induced dissociation, and the straightforwardness the present method is highly specific, accurate, precise, and should be useful in clinical settings. 相似文献
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A GC/MS method for the quantification of diacetyl is described. Diacetyl is derivatized with 4,5-dichloro-1,2-diaminobenzene to form 6,7-dichloro-2,3-dimethylquinoxaline (DCDMQ). The derivative is extracted in benzene and quantified by GC/MS. Formation of DCDMQ is linearly correlated with diacetyl concentration. The method is rapid, sensitive (determination limit 0.0005 g/mL) precise (standard error < 2%), and accurate (recovery of diacetyl 91.5% + 1.5%). 相似文献
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《Phytochemistry》1986,25(5):1143-1150
A GC/MS examination of extracts of Lycopodium clavatum var. borbonicum and L. deuterodensum revealed alkaloids which had not been previously observed in these species. New alkaloids have been found in L. australianum and in L. fastigiatum, two species which had not been investigated before. 相似文献
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Katsuhiro Nakagawa Shuichi Kawana Yuki Hasegawa Seiji Yamaguchi 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(13-14):942-948
GC/MS is widely used for the analysis of urinary organic acids for the chemical diagnosis of organic acidurias such as methylmalonic acidemia, propionic acidemia, isovaleric acidemia, glutaric aciduria type I, and multiple carboxylase deficiency. In this study, a rapid and simple preparation method for this analysis was developed in order to improve the laboratory productivity and the working environment. The solvent extraction and trimethylsilyl derivatization steps of the conventional method were improved by reducing the volume of urine sample and extraction solvent and by applying the flash-heater derivatization, respectively. The new method was successfully applied to the chemical diagnoses of five organic acidurias. 相似文献
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Huang X Shao L Gong Y Mao Y Liu C Qu H Cheng Y 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2008,870(2):178-185
This work characterized the metabolism disorders of acute liver failure (ALF) induced by carbon tetrachloride (CCl(4)) in a mouse model with different dosage of intoxication (100, 500 and 1000 mg/kg). Metabolic profiles of mice plasma were detected by gas chromatography/mass spectrometry (GC/MS) after chemical derivatization. Here an effective information-extracting approach was implemented on the basis of partial least square regression analysis (PLS-RA). PLS modeling was achieved with two kinds of Y-vectors for the acquired metabonomics data and eight metabolites with different changing behaviors were selected. ALF of mice induced by CCl(4) was characterized by the elevation of glutamate, citrate, serine and threonine, as well as the decrease of alpha-glycerophosphate, docosahexaenoic acid, palmitic acid and oleic acid in plasma. The difference in the concentrations of serine, threonine, palmitic acid and oleic acid remained insignificant between the control and 100mg/kg groups, while significant distinction appeared when comparing the control and two higher dosed groups. The underlying regulation of CCl(4)-perturbed metabolic pathways was discussed according to the selected metabolites. The present study demonstrated a great potential of PLS-RA in exploiting a comprehensive metabolic effects of CCl(4) intoxication and its efficient capability to reveal the hepatotoxic mechanism of ALF induced by reactive oxygen species (ROS). 相似文献