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1.
This is a metabolomics study for monitoring altered amino acid (AA) and organic acid (OA) metabolism of in eyes from aging an mouse model at 8 and 18 weeks and 18 months. Simultaneous metabolic profiling analysis of OAs and AAs was performed as ethoxycarbonyl/methoxime/tert-butyldimethylsilyl derivatives by gas chromatography–tandem mass spectrometry. A total of 42 metabolites—24 AAs and 18 OAs—were determined and their composition values were normalized to the corresponding mean values of 8-week-old mice as the control group. Then their normalized values were plotted as star graphs, which were distorted and readily distinguishable for each age-related group. Among the 42 metabolites, 18 AAs and 11 OAs were age dependent and significantly different (p < 0.05). Principal component analysis and partial least squares discriminant analysis showed unclear separation between 8- and 18-week-old mice but clear separation between these and 18-month-old mice. In particular, the variable importance in projection scores of 4-hydroxyproline, cis-aconitic acid, glycine, isocitric acid, leucine, pipecolic acid and lysine from partial least-squares–discriminant analysis were higher than 1.3. A heatmap for the classification and visualization of 42 metabolites showed differences in metabolite changes with aging. Altered AA and OA profiles were monitored, which may explain the metabolic disturbance of AA and OA. These findings are related to mitochondrial dysfunctions related to energy metabolism and the impaired antioxidant system in the aging eye. Therefore, the present metabolomics results of the association between physiological states and altered metabolism of AA and OA will be useful for understanding the aging eye and related diseases.  相似文献   

2.
    
Dried blood spot samples are simple to prepare and transport, enabling safe and accessible diagnostics, both locally and globally. We review dried blood spot samples for clinical analysis, focusing on liquid chromatography-mass spectrometry as a versatile measurement tool for these samples. Dried blood spot samples can provide information for, for example, metabolomics, xenobiotic analysis, and proteomics. Targeted analyses of small molecules are the main application of dried blood spot samples and liquid chromatography-mass spectrometry, but emerging applications include untargeted metabolomics and proteomics. Applications are highly varied, including analyses related to newborn screening, diagnostics and monitoring of disease progression and treatment effects of virtually any disease, as well as studies into the physiology and effects of diet, exercise, xenobiotics, and doping. A range of dried blood spot products and methods are available, and applied liquid chromatography-mass spectrometry instrumentation is varied with regard to liquid chromatography column formats and selectivity. In addition, novel approaches such as on-paper sample preparation (e.g., selective trapping of analytes with paper-immobilized antibodies) are described. We focus on research papers published in the last 5 years.  相似文献   

3.
    
An LC‐MS/MS method for determination of the anti‐epileptic drug topiramate (TPM) in dried blood spot (DBS) samples was developed and validated. DBS samples were prepared by spotting 30 μL of spiked whole blood onto FTATM DMPK‐C cards and drying for at least 3 h. Six‐millimetre punched spots were then extracted by using a mixture of methanol and water (90:10, v/v) with deuterated internal standard (topiramate‐d12). The extracted samples were injected into a liquid chromatograph equipped with a tandem mass spectrometric detector. Negative ions were monitored in the selected reaction monitoring mode and transitions m/z 338.2 → 78.1 and m/z 350.3 → 78.1 were used for the quantitative evaluation of TPM and internal standard, respectively. The results obtained from validation were statistically evaluated according to the requirements of the European Medicines Agency and US Food and Drug Administration regulatory guidelines. The linearity of the method was checked within a concentration range from 10 to 2000 ng/mL. The validation results indicate that the method is accurate, precise, sensitive, selective and reproducible. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

4.
Methotrexate, a folic acid antitumor drug, is widely used to treat childhood acute lymphoblastic leukemia. Therapeutic drug monitoring is crucial for adjusting the dosage of methotrexate according to its plasma concentration and reducing adverse effects. Micro-sampling strategies, like dried plasma spot, is an attractive but underutilized method that has the desired features of easy collection, storage, and transport, and overcomes known hematocrit issues in dried blood spot analysis. This study describes a dried plasma spot–based liquid chromatography–tandem mass spectrometry method for quantification of methotrexate. The assay showed good linearity over 30–2000 ng/mL (R2 ≥ 0.995) as well as excellent precision (0.6–9.3%) and accuracy (89.2–108.3%). Methotrexate was extracted from dried plasma spot and wet plasma samples with recoveries greater than 92.1%, and no significant matrix effect was observed. A comparison of dried plasma spot and wet plasma concentrations was assessed in 27 patients treated with methotrexate and Passing–Bablok regression coefficients showed that no significant difference between the two methods. The Bland–Altman plots showed similar agreement between the methods, indicating that the proposed dried plasma spot sampling method is an effective way to monitor the concentration of methotrexate in human plasma.  相似文献   

5.
    
A high‐performance liquid chromatography/positive ion electrospray tandem mass spectrometry method for the simultaneous quantification of lamivudine, stavudine and nevirapine was developed and validated in dried blood spot (DBS) cards. The analytes were separated using an isocratic mobile phase on a reverse phase column and analyzed by MS/MS in the MRM mode using the respective [M + H]+ ions, m/z 230–112 for lamivudine, m/z 225–127 for stavudine, m/z 267–226 for nevirapine, m/z 383–337 for zidovudine (IS). The lower limit of quantification was 1 ng/mL for both lamivudine and stavudine and 10 ng/mL for nevirapine. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The method was successfully applied to quantify them in a rat pharmacokinetic study in whole blood, plasma and DBS cards after a single oral co‐administration at the dose of 10, 2 and 13 mg/kg for lamivudine, stavudine and nevirapine, respectively, to male Wistar rats. Following oral administration the pharmacokinetic results in all the matrices are in close agreement. Thus accomplishment of this method would facilitate the ease of collection of clinical samples on DBS cards for lamivudine, stavudine and nevirapine during human clinical trials and therapeutic drug monitoring. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

6.
建立了果蔬中4种氨基酸类有机磷除草剂的非衍生化/液相色谱－串联质谱分析方法。样品采用水－二氯甲烷混合溶液提取,经二氯甲烷液液萃取法结合HLB固相萃取柱净化后,进行液相色谱－串联质谱测定。最佳实验条件下,4种化合物在0.010~0.200mg/L质量浓度范围内呈良好线性关系,相关系数（r）均大于0.996,方法检出限为0.01mg/kg,定量下限为0.05mg/kg。在0.050、0.100、0.200mg/kg3个加标水平下的平均回收率为72.2%~109%,相对标准偏差（RSD,n=6）为2.2%~11%。该方法快速、简便、灵敏、准确,可用于水果、蔬菜中氨基酸类有机磷除草剂的定量检测和确证。  相似文献   

7.
    
The AOAC 2007.1 quick, easy, cheap, effective, rugged, and safe official method, together with gas chromatography coupled to a triple quadrupole mass spectrometer was applied for the analysis of 38 multiclass pesticides from dried fruits typically cultivated and exported from Colombia: uchuva (Physalis peruviana), lulo (Solanum quitoense), guanabana (Anona muricata), and pitahaya (Hylocereus undatus). The whole method was validated in terms of matrix‐matched calibration, matrix effect, and recovery using atrazine‐d5 as internal standard, triphenylphosphate for quality control of the injection, and a proper mixture of analytes protectants. Matrix‐matched calibration data were found satisfactory for all pesticides and dried fruits, reporting R2 values above 0.99. Matrix effect values evidenced the existence of such effect in most cases. The applied procedure gave satisfactory recovery percentages (70–120%) and relative standard deviation values (< 20%) for 92% of the 456 combinations pesticide/fruit studied (spiked levels of 25, 200, and 400 µg/kg). Finally, 20 real dried fruit samples were analyzed and residues of tebuconazole were found in two samples of uchuva at a concentration below the lowest calibration level of the method for one of them and at 10.8 ± 1.6 µg/kg for the other, being below or similar to the general maximum residue level established for monitoring purposes in food applications.  相似文献   

8.
    
A simple, short, and rugged LC–MS/MS method for the simultaneous determination of tenofovir, emtricitabine, elvitegravir and rilpivirine was developed and validated. Dried blood spots were prepared with 25 μL of spiked whole blood. A 3 mm punch was extracted with methanol containing labeled internal standards. Ten microliters was injected into the LC–MS/MS using isocratic mobile phase composed of 0.1% formic acid in water and 0.1% formic acid in acetonitrile (45: 55 v/v) at a flow rate of 0.25 mL/min. The method was validated in the range of 10–2000 ng/mL for all four analytes. The intra‐assay accuracy (RE) of the method was −4.73–4.78, 1.35–2.89, −8.89 to −0.49 and − 1.40–1.81 for tenofovir, emtricitabine, elvitegravir and rilpivirine, respectively. The inter‐assay accuracy was within ±15% of nominal and precision (CV) was <15%. The hematocrit effect on quantification was nonsignificant at the tested hematocrit levels (35–70%). The dried blood spot method showed good agreement with the plasma method, and hence can be used as an alternative to plasma method.  相似文献   

9.
    
A rapid, sensitive, and widely applicable method for the simultaneous quantitative analysis of 20 underivatized amino acids in different biological matrices, including serum, plasma, and tissue homogenates, using ultra high performance liquid chromatography with tandem mass spectrometry was developed and validated. Only 4 µL of serum, plasma, or tissue homogenate was extracted with 996 µL of solution (1.7 mM ammonium formate in 85% acetonitrile containing 0.1% formic acid) containing 100 ng/mL phenylalanine‐d5 as an internal standard without any further derivatization step. In addition, the matrix effects were small because a large volume of extraction solution was used. The total run time including reequilibration was 13 min. The results of linearity, accuracy, repeatability, precision, limits of detection, limits of quantification, and sample stability were sufficient to allow the measurement of the amino acids in different biological matrices. We conclude that our method is rapid, sensitive, and widely applicable and represents an improvement over other currently available technologies.  相似文献   

10.
Metabolomics has entered the well‐established omic sciences as it is an indispensable information resource to achieve a global picture of biological systems. The aim of the present study was to estimate the influence of blood removal from mice liver as part of sample preparation for metabolomic and proteomic studies. For this purpose, perfused mice liver tissue (i.e. with blood removed) and unperfused mice liver tissue (i.e. containing blood) were compared by two‐dimensional gas chromatography time of flight mass spectrometry (GC × GC‐TOFMS) for the metabolomic part, and by liquid chromatography tandem mass spectrometry (LC‐MS/MS) for the proteomic part. Our data showed significant differences between the unperfused and perfused liver tissue samples. Furthermore, we also observed an overlap of blood and tissue metabolite profiles in our data, suggesting that the perfusion of liver tissue prior to analysis is beneficial for an accurate metabolic profile of this organ. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

11.
建立了一种测定热纤梭杆菌发酵液中的低相对分子质量有机酸的毛细管离子色谱-串联质谱方法。探索优化了色谱和质谱的检测条件,在最佳分析条件下同时检测8种有机酸。离子色谱以KOH水溶液作为流动相进行梯度洗脱;用IonSwift MAX-100毛细管柱进行分离;在喷雾电压为3.0 kV、喷雾气压强为2 000 kPa、成源温度为275℃的条件下,选择离子监测(SIM)模式下运行质谱。结果表明,柠檬酸和异柠檬酸两种同分异构体能够得到很好的分离,8种有机酸在一定浓度范围内具有良好的线性关系,相对标准偏差为1.45%~5.99%,相关系数为0.9696~0.9986,平均加标回收率为89.0%~110.0%,8种有机酸的检出限为0.01~0.50 mg/L。该方法进样量少,灵敏度高,重现性好,能够满足实际样品的检测要求,可用于嗜热厌氧菌发酵液中低分子量有机酸的测定。  相似文献   

12.
毛细管气相色谱法分析虾蛄肉中的脂肪酸   总被引：2，自引：0，他引：2       下载免费PDF全文
张强 《色谱》1996,14(5):385-387
以快速脂肪提取器分别提取雄、雌虾蛄肉中脂肪,利用５０ｍ×０．３５ｍｍｉ．ｄ．ＰＥＧ－２０Ｍ玻璃毛细管柱分离测定了雄、雌虾蛄肉中的脂肪酸,结合气相色谱／质谱法,鉴定出４５个峰,分别占脂肪酸总量的９９．２％和９８．０％,其中不饱和脂肪酸分别为７４．７％和７１．５％。  相似文献   

13.
建立了基于气相色谱-质谱联用技术(GC-MS)的血清氨基酸检测平台,研究病例组(n=80,年龄(46.82±13.39)岁)和对照组(n=37,年龄(43.46±12.79)岁)的血清氨基酸代谢谱差异,运用多元统计分析模型,结合两样本t检验、逻辑回归分析、受试者工作特征(ROC)曲线筛选与尿石症相关差异氨基酸。该方法中目标氨基酸的线性相关系数(R2)均大于0.998 5,检出限(LOD)在0.1～4.0μmol/L之间。研究结果显示,通过血清氨基酸代谢谱能够很好地区分病例组和对照组,根据变量重要性投影(VIP)>1和p<0.05筛选出的5种差异氨基酸可作为尿石症的潜在生物标志物,其联合指标的诊断灵敏度达97.3%;其中,丝氨酸ROC曲线下面积(AUC)达0.819,具有较好的临床价值,有望辅助临床进行尿石症的早期筛查诊断。  相似文献   

14.
    
For therapeutic drug monitoring in remote settings, dried blood spots (DBS) are particularly advantageous, as blood sample collection and handling is uncomplicated. The aim of this study was to develop and validate an automated extraction method for the analysis of nevirapine, efavirenz and lopinavir in DBS samples. Automated extraction was performed with methanol : water (70 : 30 v /v ), using a DBS‐MS 500 autosampler coupled to a liquid chromatography tandem mass spectrometry system. The autosampler used digital images of each DBS to position the extraction head, sprayed 10 μl of internal standard onto each DBS and extracted a 4‐mm disc (Ø) from the centre of each spot by unilateral flow using 25‐μl extraction solvent. The analytes were baseline separated on a pentafluorophenyl column and analysed by using electrospray ionization with multiple reaction monitoring in positive polarity mode for nevirapine and lopinavir and in negative mode for efavirenz. The method was linear between 10 and 10 000 ng/ml for all analytes. Automated sample extraction resulted in consistent recoveries (nevirapine: 70 ± 6%, efavirenz: 63 ± 11% and lopinavir: 60 ± 10%) and matrix effects between different donors and concentration levels. Intra‐day and inter‐day accuracy and precision deviations were ≤15%. Manual and automated extractions of DBS samples collected within the framework of an adherence assessment study in rural Tanzania showed good agreements with deviations of less than 10%. Our study highlights that therapeutic drug monitoring samples obtained in the resource‐constrained setting of rural Africa can be reliably determined by automated extraction of DBS. Overall, automatization improved method sensitivity and facilitates analysis of large sample numbers. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

15.
为应对临床中毒快检的需求,建立了干血斑样本中12种抗凝血鼠药的液相色谱-串联质谱定性定量方法。针对全打孔的干血斑样本,考察了滤纸卡种类、润湿步骤、提取溶剂种类对提取效果的影响。采用C18色谱柱进行分离,以乙酸铵(5mmol/L)水溶液-乙酸铵(5mmol/L)甲醇溶液为流动相进行梯度洗脱,在电喷雾负离子电离方式下使用三重四极多反应监测模式检测。结果表明,采用Whatman903滤纸卡为基底,以水为溶剂充分润湿,再以含内标的甲醇溶液提取5min,各鼠药的提取率为66%~115%,且结果稳定(日内RSD小于15%)。除杀鼠酮的线性范围为20~500ng/mL(r2=0.9987)外,其它11种鼠药的线性范围为5~500ng/mL(r2=0.9988~0.9996);12种鼠药的回收率为61%~105%,基质效应为71%~193%(日内RSD小于15%)。该方法准确、灵敏、快速且操作简便,成功应用于3例临床鼠药中毒病人样本的快速检测,为临床毒物检测和法医毒物分析的快速筛查和准确定量提供了新的技术方法。  相似文献   

16.
A gas chromatography/mass spectrometry (GC/MS) coupled system has been established for the confirmatory identification of abnormal urinary organic acids in inherited metabolic diseases. Samples of patient urines were extracted with an organic solvent and trimethylsilylated (TMS). A mass spectra of gas chromatographically separated TMS derivatives can be obtained using the GC/MS coupled system with a single analytical run. Those compounds with close methylene units (e.g., 4-hydroxyphenylacetaic acid and phenylpyruvic acid) in the gas chromatograph can be identified by their specific mass spectra. The results indicate that this GC/MS system is a powerful method for identifying abnormal urinary organic acids. These acids can be identified by comparison with authentic mass spectra established in our laboratories or with mass spectra files from other sources or they can be directly identified by analysis of the mass spectrum. By using this system, we were able to make positive identification of several inherited metabolic diseases found in Chinese patients, including phenylketonuria, propionic acidemia, and methylmalonic aciduria. This GC/MS system is a powerful tool for the diagnosis of inherited metabolic diseases.  相似文献   

17.
用ＨＰ６８９０ＧＣ／５９７３ＭＳＤ仪器,一次进样同时测定原油、烃源岩抽提物中芳烃馏分的芳烃色谱和色谱－质谱信息,效果良好,在有机地球化学研究工作中很有实用价值,方法具有高效、经济等优点。  相似文献   

18.
    
This review presents an overview and recent progress of strategies for detecting isomerism in peptides, with focus on d /l epimerization and the various isomers that the presence of an aspartic acid residue may yield in a protein or peptide. While mass spectrometry has become a majorly used method of choice within proteomics, isomerism is inherently difficult to analyze because it is a modification that does not yield any change in mass of the analyte. Here, several techniques used for analysis of peptide isomerism are discussed, including enzymatic assays, liquid chromatography, and capillary electrophoresis. Recent progress in method development using mass spectrometry is also discussed, including labeling strategies, fragmentation techniques, and ion‐mobility spectrometry.  相似文献   

19.
    
The ripened fruit of Schisandrae Chinensis Fructus has unique medical properties in Chinese medicine. It is commonly used after vinegar steaming. Vinegar steaming changes the color of Schisandrae Chinensis Fructus from red to black and enhances its acidic and astringent properties. Lignans are the well‐investigated components in this herb. However, Schisandrae Chinensis Fructus is acidic in the theory of Chinese medicine, and whether vinegar processing changes its organic acid components remains largely unknown. In this study, the organic acids in this herb were derived by the method of methyl esterification, and further analyzed by gas chromatography with mass spectrometry. A total of 39 organic acid compounds were identified. Interestingly, Schisandrae Chinensis Fructus after vinegar processing showed a significant increase in the content of levulinic acid as compared to the unprocessed ones. Pharmacological experiments demonstrated that levulinic acid inhibited the contractility of isolated intestine and had an inhibitory effect on the excessive hyperfunction of small intestinal propulsion. Moreover, the extracts of vinegar‐processed Schisandrae Chinensis Fructus had a stronger inhibitory on the excessive hyperfunction of small intestinal propulsion than that of unprocessed ones. Taken together, this study offers novel insight into the effect of Schisandrae Chinensis Fructus after vinegar processing.  相似文献   

20.
谢萍  韩大川 《色谱》1996,14(4):301-302
采用大口径毛细管柱技术和色谱－质谱联用技术对工业异丁基苯进行了定性和定量分析,建立了一种测定工业异丁基苯的新方法。实验结果表明新方法操作简单、快速、精密度高、复现性好。  相似文献   

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