大鼠尿液中异丙嗪及其主要代谢物的GC-MS分析

采用气相色谱-质谱(GC-MS)分析了大鼠尿液中的异丙嗪及其代谢产物。尿液经β-葡萄糖醛酸酶酶解,Oasis(HLB 3 mL固相萃取柱提取后,以Restek R tx-5MS(30 m×0.25 mm×0.25μm)石英毛细管色谱柱为分析柱,经GC-MS分离检测。根据质谱图对代谢物的结构进行鉴定。结果表明:在大鼠尿液中检出了吩噻嗪、去甲基异丙嗪、异丙嗪亚砜、2-羟基去甲基异丙嗪、二羟基异丙嗪、顺-N-(1-丙烯基)吩噻嗪、反-N-(1-丙烯基)吩噻嗪、顺-N-(1-丙烯基)吩噻嗪砜、反-N-(1-丙烯基)吩噻嗪砜、顺-N-(1-丙烯基)吩噻嗪亚砜及反-N-(1-丙烯基)吩噻嗪亚砜11种代谢物。对异丙嗪在大鼠体内的氧化、还原等主要代谢途径进行了讨论。     

格列美脲治疗的2型糖尿病大鼠的尿液代谢组学研究

采用快速高分离度液相色谱-质谱技术(RRLC-MS)检测经格列美脲治疗的2型糖尿病大鼠尿液中代谢物的变化, 对糖尿病组、 给药组和健康对照组大鼠的尿液代谢物谱进行了分析. 采用主成分分析(PCA)对3组大鼠进行分类并寻找潜在生物标记物. 结果表明, 3组大鼠的尿液代谢物谱得到了很好的区分, 发现并鉴定了2个潜在生物标记物, 分别为4-脱氧三羟基丁酸和4-胍基丁酸. 格列美脲对2型糖尿病大鼠的药物作用可能体现为对氨基酸代谢的调节作用.     

气相色谱法测定尿液中可卡因及其代谢物爱冈宁甲基酯

可卡因(cocaine,COC)在体内迅速吸收代谢,经自发水解或者酶催化水解生成主要代谢产物苯甲酰爱岗宁和爱冈宁甲基酯,以原体形式从尿液中排出仅约10%～20%.目前,尿液中可卡因及其代谢物爱冈宁甲基酯的检测方法主要有气相色谱法(GC)~([1]),气相色谱-质谱联用法(GC-MS)~([2]),高效液相色谱-质谱联用法(HPLC-MS)~([3]),毛细管电泳(CE)~([4]).本研究采用液.液萃取法提取尿液中的可卡因及其代谢物爱岗宁甲基酯,并利用气相色谱进行定性预定量检测.本方法操作简单、准确、快速.为检测可卡因滥用和法医学毒物分析提供可靠的手段.     

尿液代谢组学方法研究人参总皂苷治疗糖尿病心肌病大鼠作用机制

利用基于质谱的代谢组学方法考察了人参总皂苷(TG)治疗糖尿病心肌病(DCM)大鼠的效应机制;建立了糖尿病心肌病大鼠模型,并连续12周口服人参总皂苷,采用快速高分辨液相色谱/四级杆-飞行时间/质谱(RRLC/Q-TOF/MS)技术对糖尿病心肌病模型组(DCM组)和人参总皂苷治疗组(TG组)大鼠尿样的尿液代谢物进行分析,采用主成分分析(PCA)对两组代谢物进行分类,并寻找潜在生物标记物,同时检测心肌病理超微结构、血液生化指标和心肌氧化应激水平。RRLC/Q-TOF/MS检测结果表明,DCM组和TG组大鼠的尿液代谢物谱能得到很好的区分,发现并鉴定了3种生物标记物。TG降低了DCM大鼠心肌超微结构损伤并改善其血脂、血糖及心肌氧化应激水平,代谢组学研究结果表明:作用机制可能是TG对柠檬酸循环、脂肪酸代谢和氧化应激水平的调节作用。     

大鼠尿中硝基安定与尼美西泮及其代谢物的GC-MS检测

采用GC-MS比较了硝基安定和尼美西泮在大鼠体内产生的代谢产物,确定了尼美西泮在大鼠体内的代谢途径.给大鼠急性喂食硝基安定和尼美西泮,收集24 h内尿液,尿样用β葡萄糖醛酸酶水解,Oasis(R)HLB柱固相提取,以DB-35 MS柱为分离柱,气相色谱-质谱联用检测.从大鼠尿液中检出3种硝基安定代谢物:7-乙酰氨基硝基安定、7-氨基硝基安定和2-氨基-5-硝基苯基苯甲酮;4种尼美西泮代谢物:7-乙酰氨基尼美西泮、7-乙酰氨基硝基安定、7-氨基尼美西泮和2-氨基-5-硝基苯基苯甲酮,检出少量尼美西泮原体.并推断出2种药物在大鼠体内的代谢途径.     

固相萃取-气相色谱-质谱法检测尿液中乙基葡萄糖醛酸苷

建立了固相萃取(SPE)-气相色谱-质谱(GC-MS)检测尿液样本中乙基葡萄糖醛酸苷(EtG)的方法.1 mL尿液样本经100μL 3 mol/L盐酸去蛋白后,通过SPE法提取上清液中的目标物质及内标,提取物经衍生化后,采用GC-MS检测,选择离子模式(SIM)扫描,内标法定量分析.该方法在0.1～3.2 mg/L范围...     

非靶向尿液代谢组学方法研究五味子治疗精尿病并发症作用机制

采用超高效液相色谱-串联四级杆飞行时间质谱联用技术(Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry,UPLC/Q-TOF-MS),结合主成分分析技术(Principal component analysis,PCA),进行了五味子治疗糖尿病并发症大鼠尿液代谢组学研究,对五味子治疗糖尿病并发症大鼠后尿液生物标志物变化进行了考察.采用UPLC/Q-TOF-MS方法分析了健康组、糖尿病并发症模型组和五味子给药组的大鼠尿液,采用偏最小二乘法-判别分析(Partial least squares discriminant analysis,PLS-DA)和正交偏最小二乘法-判别分析(Orthogonal partial least squares discriminant analysis,OPLS-DA)载荷图筛选,通过分析对各组分离贡献较大(VIP>1,P°0.05)化合物的串联质谱数据,再经Human Metabolome Data-base(HMDB)等数据库检索,进行质谱信息匹配,尿液中共鉴定出28种潜在生物标记物,其中正谱13种,负谱15种.这些生物标记物主要影响戊糖和葡糖醛酸相互转化通路、核黄素代谢、泛酸和CoA合成、精氨酸和脯氨酸代谢、肠内菌代谢、嘌吟代谢、Vc代谢胆酸合成、色氨酸代谢等通路,五味子从能量代谢、氨基酸代谢、肠内菌代谢、脂类代谢等各个角度发挥治疗糖尿病并发症的作用.从各个通路的相关生物功能分析,五味子治疗糖尿病肾病的作用较强,此外还具有降脂、抗氧化的功效.     

气相色谱-质谱结合随机森林鉴定糖尿病小鼠经诺和龙治疗代谢轨迹

采用气相色谱-质谱法(GC-MS)同时测定经诺和龙治疗的2型糖尿病KK-ay小鼠和C57BL/6J健康对照组小鼠尿液中的多种代谢物。利用随机森林算法对经诺和龙治疗后不同周期的2型糖尿病(T2DM)KK-ay小鼠的GC-MS数据进行统计分析,获得小鼠经治疗后的代谢轨迹图。样品预处理中,以核糖醇为内标,用甲醇除蛋白,尿酶除去尿素,经N2吹干后用肟化-硅烷化法进行衍生;GC-MS测定中,采用DB-5MS毛细管柱程序升温分离尿样中的多种成分,并结合NIST标准质谱库和标准品对尿液中代谢物进行定性定量分析,共鉴定出氨基酸、脂肪酸、有机酸、酯类和糖类等40种内源性代谢物质。将得到的数据输入随机森林进行建模分析,得到其治愈轨迹图。研究结果表明,诺和龙能有效地改善糖尿病小鼠的血糖代谢。     

黄芪口服液降低大鼠顺铂毒性作用机制的尿液代谢组学研究

采用基于液相色谱-飞行时间质谱联用(LC-TOF-MS)技术的代谢组学方法,分析大鼠尿液内源性代谢物的变化,研究黄芪口服液(HO)降低大鼠顺铂(CDDP)毒性的作用机制.采用低剂量多次腹腔注射CDDP的方法建立CDDP染毒大鼠模型,并连续给予16天HO.于第18天收集正常对照(Control)组、顺铂模型(CDDP)组和黄芪口服液(HO)组大鼠的24 h尿液, 进行LC-TOF-MS分析,以获取尿液代谢物组数据集,对所得数据进行主成分分析(PCA)和正交偏最小二乘法-判别分析(OPLS-DA)等多元统计分析,以筛选潜在生物标志物.于第20天采集大鼠血清测定肌酐和尿素氮水平.血清指标测定结果表明, HO可以显著降低CDDP染毒大鼠的肌酐和尿素氮水平(p<0.05).PCA得分图显示,3组可分别聚类,HO组位于Control组和CDDP组中间,表明HO可部分改善CDDP所致大鼠尿液代谢产物的异常变化.综合OPLS-DA分析、t检验和倍数变化分析结果,最终共筛选并初步鉴定出35个尿液代谢产物作为HO减毒相关的潜在生物标记物.代谢通路分析结果表明,HO可通过纠正体内氨基酸代谢、能量代谢和核苷酸代谢等通路的紊乱,降低CDDP所致机体毒性.     

气相色谱-质谱结合化学计量学方法用于2型糖尿病小鼠尿液代谢物的定性定量分析

建立了气相色谱-质谱(GC-MS)同时测定2型糖尿病(Type 2Diabetes Melli-tus,T2DM)KK-ay小鼠尿液中多种代谢物的方法。样品预处理中,以核糖醇为内标,用甲醇去除蛋白,尿酶去除尿素,经N2吹干后用肟化-硅烷化法进行衍生;气相色谱-质谱测定中,采用DB-5MS毛细管柱程序升温法分离尿样中的多种成分。获得二维数据后用直观推导式演进特征投影法(HELP)对重叠色谱峰进行解析,并结合NIST标准质谱库和标准品对尿液中的代谢物进行定性定量分析,共鉴定出氨基酸、糖类、脂肪酸、有机酸和酯类等43种内源性代谢物质。结果表明,该方法简便快捷,易于操作,且灵敏度高,能够同时检测尿液中的多种组分。     

Rapid discrimination of fatty acid composition in fats and oils by electrospray ionization mass spectrometry.

Fatty acids in 42 types of saponified vegetable and animal oils were analyzed by electrospray ionization mass spectrometry (ESI-MS) for the development of their rapid discrimination. The compositions were compared with those analyzed by gas chromatography-mass spectrometry (GC-MS), a more conventional method used in the discrimination of fats and oils. Fatty acids extracted with 2-propanol were-detected as deprotonated molecular ions ([M-H]-) in the ESI-MS spectra of the negative-ion mode. The composition obtained by ESI-MS corresponded to the data of the total ion chromatograms by GC-MS. The ESI-MS analysis discriminated the fats and oils within only one minute after starting the measurement. The detection limit for the analysis was approximately 10(-10) g as a sample amount analyzed for one minute. This result showed that the ESI-MS analysis discriminated the fats and oils much more rapidly and sensitively than the GC-MS analysis, which requires several tens of minutes and approximately 10(-9) g. Accordingly, the ESI-MS analysis was found to be suitable for a screening procedure for the discrimination of fats and oils.     

Metabolic studies with phenobarbitone, primidone and their N-alkyl derivatives: quantification of substrates and metabolites using chemical ionization gas chromatography-mass spectrometry

Metabolic studies with phenobarbitone, primidone and some of their N-alkyl derivatives required the concurrent assay of any mixture of these substrates (twelve compounds) and their major metabolites (an additional twenty-two compounds) in urine. The method described in the present report met this requirement by incorporating two complementary derivatization techniques into a gas chromatographic-mass spectrometric (GC-MS) assay procedure. Following hydrolysis of conjugates with beta-glucuronidase, urine samples were extracted with ethyl acetate (3 X 5 ml). The combined extracts were dried over sodium sulphate, divided into two equal portions, and the solvent was removed. One residue was derivatized by propylation using 1-iodopropane with base catalysis. The other residue was silylated using methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide. The derivatives in each case were analysed by GC-MS, using temperature-programmed packed-column GC and chemical ionization MS. Mass spectra were acquired over an appropriate mass range, and peak areas for the compounds of interest were determined from specific mass chromatograms. Satisfactory precision, accuracy, specificity and sensitivity were obtained for all analytes. All compounds produced satisfactory derivatives by at least one procedure; twelve compounds could be analysed by both techniques. The method illustrates the utility of chemical ionization GC-MS for the simultaneous quantitative analysis of multiple related analytes in complex biological samples.     

气相色谱-质谱法测定富硒酵母中的硒蛋氨酸

建立了气相色谱-质谱（GC-MS）测定富硒酵母中硒蛋氨酸含量的方法。比较了3种从样品中提取硒蛋氨酸方法的效果。样品在三羟甲基氨基甲烷（Tris）缓冲液中酶解24 h后,以丁醇及三氟乙酸酐为衍生化试剂对硒蛋氨酸进行衍生化,采用选择离子模式对衍生物进行GC-MS测定。硒蛋氨酸的回收率为98.5%~103.7%,相对标准偏差为0.9%~2.4%,检出限为0.5 mg/L（S/N=3）。对实际样品进行测定,得到样品中硒蛋氨酸的含量结果。该法简便快速,准确可靠,灵敏度高。     

Global and selective detection of organohalogens in environmental samples by comprehensive two-dimensional gas chromatography-tandem mass spectrometry and high-resolution time-of-flight mass spectrometry

We successfully detected halogenated compounds from several kinds of environmental samples by using a comprehensive two-dimensional gas chromatograph coupled with a tandem mass spectrometer (GC×GC-MS/MS). For the global detection of organohalogens, fly ash sample extracts were directly measured without any cleanup process. The global and selective detection of halogenated compounds was achieved by neutral loss scans of chlorine, bromine and/or fluorine using an MS/MS. It was also possible to search for and identify compounds using two-dimensional mass chromatograms and mass profiles obtained from measurements of the same sample with a GC×GC-high resolution time-of-flight mass spectrometer (HRTofMS) under the same conditions as those used for the GC×GC-MS/MS. In this study, novel software tools were also developed to help find target (halogenated) compounds in the data provided by a GC×GC-HRTofMS. As a result, many dioxin and polychlorinated biphenyl congeners and many other halogenated compounds were found in fly ash extract and sediment samples. By extracting the desired information, which concerned organohalogens in this study, from huge quantities of data with the GC×GC-HRTofMS, we reveal the possibility of realizing the total global detection of compounds with one GC measurement of a sample without any pre-treatment.     

人参皂苷Rb1在大鼠体内的药物代谢研究

人参皂苷Rb1是人参中的达玛烷型三萜皂苷类化合物, 具有多种生物活性. 对人参皂苷Rb1代谢产物的分析已有报道, 在大鼠尿液、粪便、胃和大肠中共检出了5种代谢产物. 本文采用高效液相色谱-飞行时间串联质谱进行人参皂苷Rb1的体内代谢研究, 通过口服和静脉给予药物, 在大鼠尿液中共检出了人参皂苷Rb1的14种代谢产物, 并系统分析和推断了这些代谢物的转化规律和可能结构.     

基于非靶标筛查的超高效液相色谱-三重四极杆质谱法检测尿液样品中的酰基肉碱

建立了一种基于母离子扫描模式的超高效液相色谱-三重四极杆质谱检测尿液中酰基肉碱的分析方法。对酰基肉碱类化合物所共有的m/z为60、85和144的碎片离子进行选择性检测,结合化合物母离子扫描的结果及其对应的保留时间,选取一致性较好的化合物进行筛选,再利用高分辨质谱确认,最终检测到37种酰基肉碱化合物,其中有14种尚未被HMDB和LIPID MAPS数据库收录。该方法可应用于其他生物样本(如血液、组织)中酰基肉碱的定性、定量分析,可作为检测酰基肉碱化合物的新选择。     

Chemical fingerprinting of petroleum biomarkers in biota samples using retention-time locking chromatography and multivariate analysis

This work was conducted to study a new separation and evaluation approach for the chemical fingerprinting of petroleum biomarkers in biota samples. The final aim of this work was to study the correlation between the observed effects in the shore habitats (mussels and limpets) and one pollution source: the oil spill of the Prestige tanker. The method combined a clean-up step of the biota extracts (mussels and limpets), the retention-time locking of the gas chromatographic set up, and the multivariate data analysis of the chromatograms. For clean-up, solid-phase extraction and gel permeation chromatography were compared, and 5g Florisil cartridges assured the lack of interfering compounds in the last extracts. In order to assure reproducible retention times and to avoid the realignment of the chromatograms, the retention-time locking feature of our gas chromatography-mass spectrometry (GC-MS) set up was used. Finally, in the case of multivariate analysis, the GC-MS chromatograms were treated, essentially by derivatization and by normalization, and all the chromatograms at m/z 191 (terpenes), m/z 217-218 (steranes and diasteranes) and m/z 231 (triaromatic steranes) were treated by means of principal component analysis. Furthermore, slightly different four oil samples from the Prestige oil spill were analyzed following the Nordtest method, and the GC-MS chromatograms were considered as the reference chemical fingerprints of the sources. In this sense, the correlation between the studied samples, including sediments and biota samples, and the source candidate was completed by means of a supervised pattern recognition method. As a result, the method proposed in this work was useful to identify the Prestige oil spill as the source of many of the analyzed samples.     

Liquid chromatographic-mass spectrometric analysis for screening of patients with cystinuria, and identification of cystine stone.

Analyses of amino acids in the urine of a normal human and of patients with heterozygous and homozygous cystinuria have been carried out, using liquid chromatography-mass spectrometry with an atmospheric pressure ionization interface system. A kidney cystine stone was also analysed by this system. Very intense quasi-molecular ions ([M + H]+) of standard cystine, arginine, lysine and ornithine were observed on mass chromatograms as base peaks. Mass chromatograms of the urine samples from a normal human and from patients with heterozygous and homozygous cystinuria were easily distinguishable. The retention times in the mass chromatogram and mass spectrum of kidney stone cystine was almost the same as that of authentic cystine.     

Studies on the emission behavior of polypropylene by gas chromatography/mass spectrometry with static headspace or thermodesorption

Emissions from polypropylene (PP) may cause undesired smell, be harmful, or lead to so-called fogging which prohibits its use for car interiors. Thus, qualitative as well as quantitative emission studies are necessary. Thermodesorption (TDS) and static headspace (sHS) with subsequent GC-MS analysis are two powerful tools for analyzing the emission behavior of polymers with a minimum of sample handling. In this work we investigated the emission behavior of PP with TDS and sHS coupled to GC-MS paying special attention to quantitative considerations and to the relevance of emitted substances for fogging phenomena. After extraction for 30min and incubation for 2h, TDS-GC-MS and sHS-GC-MS results were satisfyingly repeatable (with relative standard deviations up to 5%). TDS allowed to introduce substances up to higher boiling points into the GC-MS system, but required to control sample geometry, as emission depended rather on sample surface than on sample mass. In sHS, emission was governed by partitioning between the gas and the sample phase rather than by full evaporation of the analytes. Above a certain analyte-dependent amount, peak area became independent of the sample amount. However, if the sample amount was kept constant, peak areas of emitted substances showed a linear dependence upon concentration of volatiles. Therefore, accurate quantitation was still possible. Typically alkanes, alkenes and dialkenes dominate TDS-GC-MS and sHS-GC-MS chromatograms of PP. They only contributed to fogging if they had a chain length higher than C16. These substances were only detectable when TDS was used for sample introduction, but not with sHS. sHS-GC-MS is thus not useful for judging fogging behavior.     

Analysis of Ultraviolet-Absorbing Compounds in Human Urine by High Performance Liquid Chromatography

Abstract

Ultraviolet (UV)-absorbing compounds in human urine were analyzed by means of high-performance liquid chromatography using the column of macroreticular anion exchange resin maintained at 60°C. The sample was eluted with a linear gradient of water to 0.25 M ammonium perchlorate-acetonitrile (85:15) at 0–50 min and with 0.25 M ammonium perchlorate-acetonitrile (85:15) at 50–70 min and monitored with absorption at 254 nm. Reproducible chromatograms were obtained and 68 well resoluted peaks were numbered. The storage of a urine sample at ?-20°C for 7 weeks did not significantly affect the chromatogram. The correlation coefficients of every pair of the numbered peaks were calculated to examine the daily variations and the individual difference of the UV-absorbing urine components.