固相微萃取气质联用分析百里香花和叶挥发性成分

利用顶空固相微萃取技术(SPME)采集百里香Thymus mongolicus花和叶的挥发性成分,采用GC/MS技术分析鉴定,并用峰面积进行归一化定量。结果表明,从百里香花和叶总离子流图中分别鉴定出24、14种化合物,分别占总峰面积的99.573%和97.187%。百里香花和叶主要成分包括酚类和萜烯类,其中百里香酚在百里香花和叶中分别占35.38%和49.13%。     

牛蒡籽油中脂肪酸成分的气相色谱-质谱联用分析

牛蒡 (ＡｒｃｔｉｕｍｌａｐｐａＬ .)是菊科 (Ｃｏｍｐｏｓｉｔａｅ)牛蒡属(ＡｒｃｔｉｕｍＬ .)植物 ,二年生草本 ,普遍分布于全国各地 ,野生或栽培。其根、叶、瘦果和籽均入药 ;茎皮纤维可造纸 ;根部含大量菊糖 ,可酿酒及作蔬菜食用 ;另外 ,还可以作为蜜源和饲料[1～ 4 ] 。据记载 ,其种子含油 2 5 %～ 30 % ;另据文献报道 ,其脂肪酸的主要成分为软脂酸、硬脂酸及油酸的甘油酯[2 ] 。牛蒡是耐盐植物 ,前人虽对其进行了较多的研究 ,但未见其籽油脂肪酸组成的准确报道 ,本文用气相色谱 质谱联用进行分析 ,以期为耐盐植物的开发利用积累部分…     

气相色谱—质谱联用技术在植物激素分析中的应用

本文结合自己多年来工作的体会介绍了GC—MS技术如何用于植物激素分析和在分析过程中应注意的关键技术问题。     

现代气相色谱- 质谱联用技术 在分析不同果品香气成分中的应用

本文概述了现代气相色谱-质谱（GC-MS）联用技术在测定不同果品香气成分中的应用,以期为果品的鲜食与加工提供参考依据。     

分析植物组织中海藻糖的气质联用及毛细管气相色谱法

介绍一种用1-甲基咪唑为溶剂和催化剂、盐酸羟胺和乙酸酐为肟化和乙酰化试剂,对植物样品中海藻糖等糖类物质进行乙酰化衍生化后的气相色谱分离、质谱鉴定的分析方法.以核糖醇为内标,通过校准曲线对植物组织中的海藻糖进行定量分析.此法测定海藻糖的最低量可达8.17×10-11g,适于植物样品中微量海藻糖的分析测定.     

甘肃岷县当归不同药用部位挥发油的提取及其成分分析

采用水蒸气蒸馏法分别提取产于甘肃岷县道地产区当归的当归身、当归尾、当归头中的挥发油,使用气相-质谱联用(GC-MS)分析其挥发油的化学组分.在相同提取测定条件下,当归不同部位提取的挥发油中各化学成分含量存在差异性,当归身、当归尾、当归头在保持较多藁本内酯的同时,均含有其他有效成分,且这些有效成分种类与含量不尽相同.提示当归不同药用部位的挥发油化学成分含量具有一定的差异,药理作用的物质基础不同,探寻当归不同部位的挥发油的化学成分变化规律,为中药当归的加工及临床应用提供科学依据.     

气相色谱-三重四级杆质谱联用仪测定蔬果中38种农药残留及其在20种基质中的基质效应

建立了蔬果中38种农药残留检测的气相色谱-三重四级杆质谱联用（GC-MS/MS）方法,甲胺磷、δ-六六六回收率在79.8%~84.9%之间,另外36种农药回收率在96.4%~114.1%之间,RSD值在3.3%~9.3%之间。探讨了38种农药残留及其在20种蔬果产品中的基质效应,在GC-MS/MS上,主要表现为基质增强效应,随着化合物浓度增大,基质增强效应减弱。为保证检测结果的准确性,必须使用基质标样进行校正,当选取黄瓜或大白菜作为基质配制标样进行定量时,大部分农药在另外19种蔬果产品中的回收率能达到80%~130%之间。     

花椒挥发油的化学成分分析及体外抑菌活性研究

目的:明确花椒挥发油的主要化学成分及对部分细菌、真菌的体外抑菌活性.方法:①采用水蒸气蒸馏法提取花椒中挥发油并进行GC/MS分析;②K-B纸片扩散法和浓度稀释法测试6种菌株(金黄色葡萄球菌ATCC25923、大肠埃希菌ATCC25922、铜绿假单胞菌ATCC27853、枯草杆菌ATCC6633、白色假丝酵母菌ATCC90028、近平滑假丝酵母菌ATCC22019)体外抑菌活性.结果:①GC/Ms法分离出80余个峰,鉴定出81种物质,用面积归一法确定其相对百分含量;其中5种化合物已占到总量的60%以上,分别为桉树脑15.64%、4-萜品醇15.60%、D-柠檬油精13.72%、β-月桂烯10.20%、α-蒎烯4.03%.②花椒挥发油除对铜绿假单胞菌抑菌活性不明显外,对其它5种菌株均有较好的抑菌活性.结论:①花椒挥发油中化学成分复杂,其中含量超过5%的成分仅4种且最高含量小于16%.②花椒挥发油具有明显体外抑菌活性.     

固相微萃取—气相色谱—质谱联用分析蓼实挥发性成分

察了萃取样品温度、萃取纤维吸附时间等因素对于固相微萃取蓼实挥发性成分的影响,确定较佳的实验条件为：萃取样品温度60℃,萃取纤维吸附时间60 min,脱附温度250℃,脱附时间5 min。用气相色谱—质谱联用技术测定上述条件所得蓼实挥发性化学成分,并鉴定出其中43种,占总峰面积的76.73%。其中含量较高的物质有：罗汉柏烯 (6.99%),丁香烯 (5.59%),2,5,5,8 a-四甲基-6,7,8,8a 四氢-5H-萘-1-酮(5.52%),α-丁香烯(4.29%),1,2,4a,5,6,8a-六氢-4,7-二甲基-1-异丙基萘(4.04%),环氧石竹烯(3.60%),α-香附酮(3.54%),4,5,5a,6,6a,6b-6氢-4,4,6b-三甲基-2-乙烯基-2H-环丙香豆酮(3.54%),香叶基丙酮(3.48%)。     

‘长营’橄榄果实挥发性成分分析

采用固相微萃取法和气相色谱-质谱联用法,对福建闽侯地区的优良橄榄品种'长营'橄榄(Canarium album'Changying')果实的香气成分进行分析,分离出22个峰,确认了22种化学物名称及其相对含量.结果表明:'长营'橄榄挥发油主要成分为石竹烯、八氢-7-甲基-3-亚甲基-4-异丙基-1H-五环[1,3]三环[1,2]苯、1,2,3,5,6,8a-六氢-4,7-二甲基-1-异丙基萘、古巴烯、α-石竹烯、丁基羟基甲苯、β-蒎烯、α-毕澄茄油烯等,其中石竹烯含量最高,达42.40%.比较'冬节圆'橄榄、'三棱'榄橄的挥发物成分,表明橄榄挥发物的主要成分为烯类,但成分各不相同.可见不同品种或不同产地的橄榄香气成分差异较大.     

气相色谱-质谱法测定中药沙苑子中的氨基酸

本文利用气相色谱一质谱(GC/MS)联用技术首次对中药沙苑子中的氨基酸进行了定性定量分析。沙苑子经盐酸水解后,对其氨基酸水解液进行羟基脂化和氨基酰化的衍生化反应,利用GC/MS法共测得15种氨基酸,由外标法测定了每种氨基酸的含量。由此得出沙苑子中氨基酸的总质量分数为4.23％。     

Analysis of Substituted Pyridine-C-Nucleosides by Direct Liquid Introduction Liquid Chromatography/Mass Spectrometry

Abstract

A method was elaborated for the analysis of a few original pyridine-C-nucleosides via microbore DLI/LC-MS. The compounds were analyzed on a 10RP8 column (25 cm × 1 mm) using a number of 0.01 M HCOONH₄/CH₃OH mixtures as eluant. Under appropriate LC-MS conditions, both α- and β-anomers were separated and identified. All nucleosides were characterized by the protonated molecular ion [MH]+, [B+30]+ and [B+44]+-fragment ions. Assignment of the α, β-configuration at C₁′ was done with the aid of ¹³C-NMR. From the DLI/LC-MS data, a semi-preparative HPLC-method was developed to purify the pyridine-C-nucleosides prior to biological evaluation.     

Estimation of D-Arabinose by Gas Chromatography/Mass Spectrometry as Surrogate for Mycobacterial Lipoarabinomannan in Human Urine

Globally, tuberculosis is slowly declining each year and it is estimated that 37 million lives were saved between 2000 and 2013 through effective diagnosis and treatment. Currently, diagnosis relies on demonstration of the bacteria, Mycobacterium tuberculosis (Mtb), in clinical specimens by serial sputum microscopy, culture and molecular testing. Commercial immunoassay lateral flow kits developed to detect Mtb lipoglycan lipoarabinomannan (LAM) in urine as a marker of active TB exhibit poor sensitivity, especially in immunocompetent individuals, perhaps due to low abundance of the analyte. Our present study was designed to develop methods to validate the presence of LAM in a quantitative fashion in human urine samples obtained from culture-confirmed TB patients. Herein we describe, a consolidated approach for isolating LAM from the urine and quantifying D-arabinose as a proxy for LAM, using Gas Chromatography/Mass Spectrometry. 298 urine samples obtained from a repository were rigorously analyzed and shown to contain varying amounts of LAM-equivalent ranging between ~10–40 ng/mL. To further substantiate that D-arabinose detected in the samples originated from LAM, tuberculostearic acid, the unique 10-methyloctadecanoic acid present at the phosphatidylinositol end of LAM was also analyzed in a set of samples and found to be present confirming that the D-arabinose was indeed derived from LAM. Among the 144 samples from culture-negative TB suspects, 30 showed presence of D-arabinose suggesting another source of the analyte, such as disseminated TB or from non-tuberculosis mycobacterium. Our work validates that LAM is present in the urine samples of culture-positive patients in small but readily detectable amounts. The study further substantiates LAM in urine as a powerful biomarker for active tuberculosis.     

天然除虫菊素的毛细管气相色谱定量分析

本文建立了一种利用毛细管气相色谱从除虫菊提取物中分离六个有杀虫活性菊酯类化合物,并进行定量分析的方法.采用15 m × 0.25 mm i.d.0.25 μm 的DB-1MS石英毛细管柱,柱温从150至242 ℃分二阶程序升温分离除虫菊提取物中六个有杀虫活性菊酯类化合物,以邻苯二甲酸二丁酯为内标物,用FID检测器进行六个化合物的定量分析.该方法线性相关系数为0.9995,高、中、低三个水平的添加回收率分别为99.7%、99.4%和99.3%.     

Evaluation of HCH,DDT and Endosulfan Levels in Soil by Gas Chromatography/Tandem Mass Spectrometry

Persistent organic pollutants (Σ DDX, Σ HCH, and Σ Endosulfan) were quantified in top soil and deep soil of a pesticide manufacturing industry. It was also possible to identify the presence of some other organochlorinated compounds (OCs) in the soil. A suitable multiresidue analysis of persistent organic pollutants in soil samples was developed based on soxhlet extraction and gas chromatography–mass spectrometry for quantifying parent compounds and degradation products, namely OCs and other miscellaneous pesticides. The quantification protocol was developed using Programmed Temperature Vaporization (PTV) and GC/MS/MS as identification tools. Extraction, PTV and MS/MS conditions were optimized for 11 pesticides with unambiguous spectral confirmation. The protocol has been applied to a large number of environmental samples and has proved to be reliable. The degradation ratios between the parent substances and their metabolites (DDX and HCH isomers) were calculated to determine whether there were any fresh inputs of parent pesticide at the site. Pesticide concentrations in the low to high concentration range (159 μ g/kg to 133 mg/kg) have been measured. The investigations clearly indicate pesticide contamination in the soil.     

Quantitative Analysis of Cytokinins in Plants by High Performance Liquid Chromatography: Electronspray Ionization Ion Trap Mass Spectrometry

The present paper introduces a highly sensitive and selective method for simultaneous quantification of 12 cytokinins(free form and their conjugates).The method includes a protocol of extraction with methanol/water/formic acid(1514/1,v/v/v)to the micro-scale samples,pre-purification with solid phase extraction(SPE)cartridges of the extracts,separation with a high performance liquid chromatography(HPLC)and detection by an electrospray ionization ion trap mass spectrometry(ESI-Ion trap-MS)system in a consecutive ion monitoring(CRM)mode at the three stage fragmentation of mass spectrometry(MS3).The lowest detection level of the cytokinins of the method reaches 0.1-2.0 pg with a very wide range of linear regression from 1-512 pg,at the coefficient factors of 0.98-0.99.The feasibility of this method has been proven in the application of the method to the analysis of the trace-amount contents of cytokinins in the micro-scale samples of various types of plant materials,such as aerial parts of rice and poplar leaves etc.12 endogenous cytokinins had been identified and quantified in the plant tissues,with an acceptable relatively higher recovery rate from 40% to 70%.     

The Identification of 5′-Deoxy-5′-Methylthioguanosine in Human Urine by Gas Chromatography/Mass Spectrometry

Abstract

5′-Deoxy-5′-methylthioguanosine (MTG) has been identified in human urine by combined gas chromatography/mass spectrometry. Preliminary identification of MTG in the urine of a lung cancer patient was based upon mass spectral comparisons of the trimethylsilylated (TMS) urinary component to both MTA-(TMS)₃ and guanosine-(TMS)₅. Structural confirmation was obtained by comparing the mass spectral and chromatographic characteristics of authentic MTG to those of the urinary component.