Bohai crude oil identification by gas chromatogram fingerprinting quantitative analysis coupled with cluster analysis

By gas chromatogram, six crude oils fingerprinting distributed in four oilfields and four oil platforms were analyzed and the corre- sponding normal paraffin hydrocarbon （ including pristane and phytane） concentration was obtained by the internal standard methed. The normal paraffin hydrocarbon distribution patterns of six crude oils were built and compared. The cluster analysis on the normal paraffin hydrocarbon concentration was conducted for classification and some ratios of oils were used for oils comparison. The results indicated： there was a clear difference within different crude oils in different oil fields and a small difference between the crude oils in the same oil platform. The normal paraffin hydrocarbon distribution pattern and ratios, as well as the cluster analysis on the nomad paraffin hydrocarbon concentration can have a better differentiation result for the crude oils with small difference than the original gas chromatogram.

GC/MS: A Valid Tool for Soil Gas Hydrocarbons Speciation

This work describes an alternative method based on GC/MS technique with SCAN-ion approach for speciation of hydrocarbons contained in soil gas matrices and sampled on solid sorbent tubes (coconut shell charcoal).

Study on the Specific GC Chromatograms of Volatile Oil from Xinyi Biyan Pills

[Objectives]This study was conducted to establish characteristic chromatograms of of the volatile oil of Xinyi Biyan Pills by gas chromatography,discover possible problems in the production processes of different manufacturers,and further improve the quality control methods.[Methods]The volatile oil in samples was extracted and tested by gas chromatography to collect chromatograms,which were analyze and evaluated by the similarity evaluation software of chromatographic fingerprints of traditional Chinese medicine.[Results]Nineteen common peaks were calibrated in the characteristic chromatograms;and the characteristic chromatograms of samples produced by different manufacturers were obviously different.[Conclusions]Controlling the volatile components in Xinyi Biyan Pills by the established characteristic chromatograms of GC is accurate and feasible,and can be used as a quality control method for Xinyi Biyan Pills.

Research on Comparison of Gas Chromatography and Liquid Chromatogram Detecting Pesticide Residue

The existing methods of detecting pesticide residue include gas chromatography, high performance liquid chromatography, gas chromatograph-mass, liquid chromatograph-mass, capillary electrophoresis, radioimmunoassay, biosensor and rapid detection on the spot. The paper analyzes the comparison of gas chromatography and liquid chromatogram detecting pesticide residue, for achieving the development tendency and the future goal of analyzing pesticide residue.

Determination of 7 Indictor Polychlorinated Biphenyls (PCBs) Residues in Porphyra by Ultrasonic Extraction and Gas Chromatography (GC)

A method was developed for determination of 7 indictors the polychlorinated biphenyls (PCBs) residues in porphyra by gas chromatography (GC) with electron capture detector (ECD). The PCBs were extracted with hexane/methylene chloride (1:1, v/v) by ultrasonic extraction and the samples were cleaned up by concentrated sulfuric acid and Alumina-N solid phase extraction cartridge. The analytes were quantified by an internal standard method. Under optimal experimental conditions, good linearity was observed in the range of 5 - 200 ng/mL and the correlation coefficients were 0.9994 - 0.9998. The limit of quantitation (LOQ) for target analytes ranged from 6.0 to 10.0 μg/kg. At the spiked levels of 10, 50, 100 μg/kg, the average recoveries ranged from 90.9% to 102% with the relative standard deviations 2.12% - 6.32%. The result showed that the proposed method was rapid, and could be used for the determination of the PCBs in porphyra.

自动固相微萃取(SPM E)GC-MS、GC-MS-MS法检测环境水中有机磷杀虫剂的研究

固相微萃取(solid-phase microextraction,SPME)是20世纪90年代发展起来的一种样品前处理技术,与传统的液-液提取、液-固提取相比,SPME更适用于提取、浓缩液态或气态的挥发性和半挥发性物质,SPME技术可将采样、萃取、浓缩和样本引入集中于一个步骤完成,尤其随着自动SPME与GC-MS等联用技术的日益完善,使SPME技术优点得到更充分的发挥.……

建立火场样品中汽油残留物ATD-GC-MS检验结果的评价方法

目的建立火场中汽油燃烧残留物ATD-GC-MS检验结果评价方法。方法将模拟燃烧样品用ATD-GC-MS法检验,检验结果通过对芳烃、烷烃、茚满、和萘系列的4个特征离子色谱图与已知汽油作比较,并利用向量夹角法计算样品与汽油色谱指纹图的相似度来对检验结果作评价。结果有汽油作助燃剂的模拟燃烧样品与汽油色谱指纹图的相似度一般大于90%,无汽油作助燃剂的样品则在60%以下。结论利用样品的4个特征离子色谱图与已知汽油作比较,并结合样品与汽油色谱指纹图相似度的计算,能对检验结果作出客观、可靠和准确的评价。

广防己挥发油的GC-MS指纹图谱研究

防己药材主要分粉防己和木防己两类,木防己包括广防己和汉中防己.广防己为马兜铃科植物广防己Aristolochia fangchi Y.C.WuexL.D.Chou.et S.M.Hwang的干燥根[1],习称"木防己"、"水防己",主产于广东、广西,具有祛风止痛、清热利水之功效[2].……

GC-MS Analysis of Essential oil and n-Hexane Extract from Moso Bamboo

[Objective] This study aimed to analyze the chemical composition and yield of essential oil and n-hexane extract from moso bamboo to find active compounds with potential value. [Method] Essential oil and n-hexane extract were respectively extracted from moso bamboo of four different ages by using hydrodistillation and ultrasonic-assisted extraction with n-hexane, and analyzed with gas chromatography/mass spectrometry （GC/MS）. [Result] The results show that cedrol （46.39%） is the first principal volatile component in essential oil of the middle stem of 7-year old moso bamboo; dibutyl phthalate （59.46%） is the first principal volatile component in n-hexane extract of the middle stem of 3-year old moso bamboo; yield of n-hexane extract is higher than that of essential oil from moso bamboo. [Conclusion] Cedrol is an active compound with potential value.

感冒清热颗粒挥发油GC特征图谱研究

目的建立感冒清热颗粒中挥发油的特征图谱,对其部分成分归属进行初步判定,为其全面质量评价提供依据。方法 Agilent HP-5毛细管柱(30 m×320 mm,0.25μm);进样口温度300℃,检测器温度320℃;柱温:初始温度65℃,保持5 min,1℃.min-1升至75℃,保持2 min,再以10℃.min-1升至180℃,保持10 min,然后以5℃.min-1升至300℃,保持10 min;载气为氮气;流速:3.8 ml.min-1;进样量为2μl,不分流。结果特征图谱中共标定了6个共有峰,精密度、稳定性、重复性都达到了要求(RSD<5%),相似度分析中,不同厂家、批次各成分的种类差异不大,但成分的比例和量上差异较大。结论建立的气相特征图谱中,各共有峰分离较好,大部分批次均检出胡薄荷酮及薄荷脑,两者分离效果达到要求,可为感冒清热颗粒的质量评价提供借鉴,为进一步严格规范中成药从选材到制备工艺的全过程提供一定的参考。

药对木香-乌药与其单味药挥发油化学成分GC-MS的比较分析

目的分析比较药对木香-乌药与其单味药的挥发油成分。方法采用水蒸气蒸馏法从药对及其木香、乌药中提取挥发油,利用气相色谱-质谱(GC-MS)联用技术进行分离检测,通过质谱自动解析鉴定系统(AMDIS)结合色谱保留指数辅助定性。结果从单味药木香、乌药及其药对挥发油中分别鉴定出72、79、99种化学成分;药对与单味药挥发油共有成分26种,为药对挥发油总含量的12.4%。结论已鉴定的药对主要成分多来自单味药木香,药对挥发油组分种类为单味药的综合结果。

用气相色谱最佳分离条件的特征值rt_0/β确定GC/MS的操作条件

作者从理论和实践上证明了在检测器、载气及色谱柱参数不同的条件下，通过改变死时间ｔ０和升温速率ｒ，保持特征值ｒｔ０／β不变。

药对萸黄连-木香挥发性成分的GC-MS分析

将药对萸黄连-木香中的挥发油成分进行气相色谱-质谱联用技术(GC-MS)检测,并用自动质谱去卷积软件(AMDIS)和保留指数(RI)定性分析,利用峰面积归一化法对化学成分定量。从药对中鉴定出76种化学组分,主要成分为去氢木香内酯(9.51%)、异土木香内酯(2.90%)、α-木香醇(4.94%)、α-檀香醇(4.40%)等。

Characteristics of gas evolution profiles during coal pyrolysis and its relation with the variation of functional groups

Strict relation between the substituents or functional groups attached to the coal macromolecules and the generation of the volatile products, e.g., CH4 H2O, CO, CO2, etc., during the coal pyrolysis is an important but confusing subject. In this paper, quadrupole mass spectronletry, gas chromatography, and ^l3C nuclear magnetic resonance are applied to real-time monitoring the formations of volatile products, off-line quantitative determination of the total products from the pyrolysis of a sub-bituminous coal (SC), and the changes of diverse substitents in the SC along with coke foamation, respectively. These measurements are also performed for the pyrolysis of a caking coal to contrast SC. The qualitative and quantitative data reveal that, during coal pyrolysis, the functional groups related with the formation of CO, i.e., ether, carbonyl, and anhydride, can directly gen erate CO via bond breaking, or take a detour of the formation of other intermediates via condensation and recombination firstly. Moreover, the formations of CO2 and CH4 are related to the direct removal of -COO- and -CH3,respectively.

芥蓝未熟种子赤霉素的GC/MS定性分析

本文介绍GC／MS法对赤霉素的定性分析方法，并确认在芥蓝未熟种子中存在GA1、GA4、GA9、GA38等4种以上赤霉素形式。

羚羊感冒片的GC指纹图谱研究

目的:建立羚羊感冒片的气相色谱(GC)指纹图谱。方法:毛细管柱为DB-5 ms毛细管柱,检测器为氢火焰离子化检测器,进样口温度为240℃,检测器温度为250℃,程序升温,载气为氮气,流速为1.0 mL/min,进样量为1μL,进样方式为分流进样,分流比为20∶1。以薄荷酮为参照物,测定10批羚羊感冒片的GC图谱,采用《中药色谱指纹图谱相似度评价系统》(2012版)进行共有峰指认和相似度评价。结果:10批羚羊感冒片的GC图谱有14个共有峰,相似度均>0.98。经验证,10批样品GC图谱与对照指纹图谱具有较好的一致性。结论:该研究所建指纹图谱可为羚羊感冒片的鉴别和质量评价提供参考。

Capillary gas chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco

Simple procedures for extraction and chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco are described.The determination was carried out by capillary gas chromatography(GC) with electron capture detection(ECD) and confirmed by GC-MS.The mean recoveries and relative standard deviation(RSD) were 93.2%～112.9% and 3.5%～6.7%,respectively at levels ranging from 0.01 to 0.1 mg/kg.The limit of determination was 0.001 mg/kg.Tobacco samples in routine check were successfully analyzed using the proposed method.

Identification and Characterization of Sulfur Compounds in Straight-Run Diesel Using Comprehensive Two-Dimensional GC Coupled with TOF MS

The solid-phase extraction using Pd-Al2O3 as the stationary phase was employed to pre-separate the sulfur compounds in straight-run diesel. The isolating effect was evaluated quantitatively by gas chromatography with a sulfur chemiluminescence detector to harvest a satisfactory result. The identification of the structure of sulfur compounds by comprehensive two-dimensional gas chromatography coupled with the time-of-flight mass spectrometry indicated that cyclo-sulfides, benzothiophenes, dibenzothiophenes, dihydro-benzothiophenes and tetrahydro-dibenzothiophenes were included in straightrun diesel obtained from the Arab medium crude(AM). A total of 259 individual compounds were detected and their molecular structures were identified. The analytical method was approved as an effective way to characterize the composition of sulfur compounds, which reduced the interference of other compounds, facilitated the data presentation and provided more detailed information about molecular composition of sulfur compounds.

A GC×GC-ToFMS Investigation of the Unresolved Complex Mixture and Associated Biomarkers in Biodegraded Petroleum

Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） has been investigated using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry（GC×GC-To FMS） within a set of biodegraded petroleums derived from distinct sedimentary basins, including northwestern Sichuan（Neoproterozoic, marine）, Tarim（Early Paleozoic, marine）, Bohai Bay（Eocene, saline/brackish） and Pearl River Mouth（Eocene, freshwater）. In general, the hydrocarbons that constitute the UCM in petroleum saturate fractions can be classified into three catalogues based on the distributions of resolved compounds on two dimensional chromatograms. Group 1 is composed mainly of normal and branched alkanes, isoprenoid alkanes and monocyclic alkanes; Group 2 comprises primarily terpanes ranging from two to five rings, and Group 3 is dominated by monoaromatic hydrocarbons such as tetralins and monoaromatic steranes. In addition, the UCM is source dependent and varies between oil populations. i.e., the UCM of petroleum derived from Precambrian and Early Paleozoic marine, Eocene saline/brackish and freshwater source rocks is specifically rich in higher homologues of A-norsteranes, series of 1,1,3-trimethyl-2-alkylcyclohexanes（carotenoid-derived alkanes）, and tetralin and indane compounds, respectively.

八角茴香中挥发油的GC特征图谱研究

目的:研究八角茴香中挥发油的GC特征图谱,为科学评价和有效控制质量提供可靠方法。方法:采用GC分析方法,聚乙二醇20000(PEG-2M)的弹性石英毛细管柱(30 m×0.53 mm,1μm)为分析柱。FID检测器。进样口温度:220℃,检测器温度:250℃,分流进样。程序升温:初温75℃,保持6min,以5℃·min^(-1)速度升至200℃,保持10 min,载气为氮气,载气流速:3 ml·min^(-1)。结果:测定了133批八角茴香样品,建立了对照特征图谱,有6个共有的特征峰,第4个峰为参照物反式茴香脑峰。结论:建立的GC特征图谱分析方法,简单、准确,可用于八角茴香的质量控制。