气相色谱近年的发展

简要阐述了近几年气相色谱(GC)的发展和特点。GC是一个成熟的技术,广泛地应用于各个领域,近几年GC的发展除了继续研究新的固定相和高性能的毛细管色谱柱之外,主要在全二维气相色谱(GC×GC)、快速GC、便携式GC仪和微型GC仪几个方面。近几年新研究的GC固定相主要集中在常温离子液体和各种环糊精的衍生物。现在GC研究者趋向于使用商品化的GC毛细管柱,而商品化的GC毛细管柱应用最多的是以含5%苯基的聚甲基硅氧烷为固定相的色谱柱。GC×GC发展迅猛,特别是关于调制器的研究,已开发出十多种调制模式,并广泛地应用于各个领域。为了适应大量样品的分析和现场分析,研究和开发了多种快速GC方法和仪器以及便携式GC仪。为了仪器的小型化和专属性检测,μGC仪的研究也稳步地发展起来。     

Radio gas chromatography on capillary columns using a multi-column system (column-switching)

Summary A gas chromatographic system with capillary columns (fused silica) for the analysis of radiolabelled compounds is described. The system presented is based on a dual column gas chromatograph equipped with column switching facllity and a variable splitter at the column outlet combined with a dead-volume free adapter for the radioactivity monitor for continous measurement of radioactivity in the column effluent. The first column works as a separation column and the second is roughly shortened and used as a feed to the mass detector. The adjustment of the split ratio is regulated by the inlet pressures for the carrier gas supplying both columns. For mass detection all conventional systems can be used. Detection of radioactivity by a gas proportional counter (system based on a combustion technique). Three flow modes can be adjusted: a) total column effluent to the mass detector or b) to the radioactivity monitor, and c) simultaneous flow (dependent on the chosen split ratio) to mass-and radioactivity detectors. The system was developed for use in clinical chemistry and tested with labelled and unlabelled steroids. The method for peak identification by means of relative retention times and methylene units was possible also for radioactive peaks when a heart cutting technique was used. The radio gas chromatographic system presented allows the development of radiochromatograms with the same peak characteristics as in conventional capillary gas chromatography.Presented at the 14th International Symposium on Chromatography London, September, 1982     

Reaction gas chromatography: Hydrogenation cracking of hydrocarbons

Summary Hydrogenation degradation of hexane, 2-methylpentane, 2,2-dimethylbutane, trans 2-hexene, cyclohexane and benzene on a nickel catalyst was studied. The degradation products were separated in a capillary column with squalane and identified using the appropriate retention indices. The results obtained (the degree of conversion and the relative content of the individual products) are discussed in connection with the thermal degradation of these substances in an inert atmosphere.     

非晶硅太阳能电池生产工艺用氣分析方法研究

本文对非晶硅太阳能电池制造工艺过程所用的无机氢化物烷类气体硅烷、硼烷、磷烷、甲烷和氢及其混合气的配制与分析方法进行了研究,以微机控制配气、检测程序、气相色谱法分成分析杂质,电容法测水分,方法已应用于工艺过程分析。     

用台式色谱-质谱仪同时进行原油芳烃色谱和色谱-质谱分析

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。     

快速气相色谱研究

近年来快速气相色谱(HSGC)技术备受关注。本文根据色谱理论和实际应用中的特点对其进行了系统的分类和评价,阐述了如何针对具体样品选择分析方法和通过调整仪器的配置、参数以及性能来实现特定的快速分析。最后提出了HSGC未来的发展趋势。     

Low-pressure gas chromatography: Recent trends and developments

In the past few years, low-pressure gas chromatography (LP-GC) has been applied for the fast analysis of various pollutants in different environmental and food matrices. A typical LP-GC set-up involves the use of a short microbore column (typically 0.5–1 m × 0.10 mm internal diameter) at the injector side connected with a zero dead-volume connector to a short megabore column (typically 10 m × 0.53 mm) to be used with higher gas velocities. This set-up maintains atmospheric injection conditions, while the analytical column is operated under low-pressure conditions that are compatible with mass-spectrometer analyzers. Although the use of LP-GC results in a loss of separation efficiency, it offers a 3–5-fold reduction in analysis time for organic compounds and thus increased sample throughput and enhancement of the signal-to-noise ratio leading to improved detection limits. Considering the significance of, and the potential interest in, this topic, this review briefly describes the concept of LP-GC. Furthermore, we explore recent developments and applications of LP-GC, with a focus on the use of various column systems and analyzers. Finally, we critically evaluate the prospects for, and the limitations of, LP-GC.     

用天然气气相色谱分析仪快速分析天然气组分及性能参数

介绍用天然气气相色谱分析仪分析天然气中无机组分、有机组分和热值的方法,确定了分析方法和条件,该方法测量结果的相对标准偏差小于1%。采用该方法对制备的标准气体进行了考察,并将该方法用于天然气气体标准物质的性能评价和国际实验室间的比对,天然气组分含量比对相对误差在±1%之内,热量值比对相对误差在±3%之内,取得了国际等效性。     

Flow of the carrier gas in open-tubular capillary columns in temperature-programmed gas chromatography

A second-order non-linear partial different equation was derived to describe the dependence of carrier gas pressure in the column on the column distance and the time under temperature programmed conditions. This equation was solved numerically by the modified finite difference method for various column parameters. Constant inlet and outlet pressures were used as boundary conditions. The retention times calculated on assumption of a constant pressure profile along the column. Significant differences between retention times of corresponding solutes calculated by the two methods were found, especially when relatively long columns(L>50m) with small internal diameter(d<0.3mm)and high temperature program rates (r>5°/min)are used.     

端羟基β-氰乙基甲基聚硅氧烷气相色谱毛细管柱的研制

Sol-gel capillary column for gas chromatography was prepared with Hydroxyl-Terminated β-cyan-ethyl methyl-Polysiloxane as stationary phase.On this column alkanes,aromatic compounds,amines,alcohols etc.were separated successfully,although the length of this column was only 2.5m.Experiments showed that the column-inertness was good and the unsymmetrical factor was 1.At high temperatures the stationary phase of the column showed excellent stability.Results showed that the relative standard deviation of the ret...     

气相色谱法测定异氟烷含量

The isoflurane content was determined by using a 93mm × 2.1m glass GC column packed with 25%PEG-20M/Chromosorb P AW-DMCS(80～100 mesh)and flame ionization detector,and the column temperature was 70℃.The quantitative determination was performed with trichloromethane as internal standard.     

气相色谱法测定榄香烯含量

以正己醇为内标,用气相色谱法测定榄香烯及其制剂,方法简便、快速,结果准确,可作为控制质量的方法。     

毛细管气相色谱法测定油田水中短链有机酸

The evaporation of water phase has been used to remove a vast amount of inorganic salts and interferingorganic components. The distillate concentrated by rotary evaporator was directly analyzed by means of wide-bore capillary GC column, The coefficients of variation for C_2～C_5 organic acids were 1.9～6.4%. The recov-eries of the acids in the oilfield water were 81.0～106%.     

Analysis of the Sulfonylurea Herbicide Metsulfuron-Methyl and Its Metabolites in the Soil of Cereal Crops. Comparative Analytical Chemistry of the Sulfonylureas

Abstract

For the analysis of metsulfuron-methyl in the crop soils with a sensitivity limit of 0.3 μg kg^?1 dry soil, in the soil extract metsulfuron-methyl was separated from its soil metabolites and the soil impurities by repeated thin-layer chromatographies (TLC). In the cleaned soil extract, diazomethane transformed metsulfuron-methyl 1 into N,N′ -dimethyl metsulfuron-methyl 2 (methyl 2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)methylamino]carbonyl]methylamino]sulfonyl]benzoate). In the gas-liquid chromatograph with detection by electron capture (GC-EC) and in the combined gas chromatograph-mass spectrometer (GC-MS), 2 was transformed into 1-dioxy-2-N-methyl-3-keto-1,2-benzisothiazole 3 which was measured by GC-EC with confirmation by GC-MS. The metsulfuron-methyl soil metabolites 2-sulfonamido-methylbenzoate 6, 1-dioxy-3-keto-1,2-benzisothiazole (saccharin) 7 and 2-sulfonamidobenzoic acid 8 were analyzed in the soil of winter wheat crops by a procedure similar to the one for metsulfuron-methyl. After their separation and purification in the soil extracts by TLC, 7 and 8 were methylated, and analyzed as 3 in the GC-EC and GC-MS apparatus where the generated 6 was quantitatively transformed into 3; 6 was analyzed as such with the GC and GC-MS apparatus wherein it was transformed into 3. The sensitivity limit for each metabolite was 0.3 μg of equivalents of metsulfuron-methyl kg^?1dry soil. The syntheses of the analysis standards of the metsulfuron-methyl derivatives 2 and 3, and of the metsulfuron-methyl metabolites 6, 7 and 8 are described. The transformation pathways of metsulfuron-methyl and of its derivatives are different from those of the pyridine-pyrimidine sulfonylurea herbicides flupyrsulfuron-methyl and rimsulfuron. The soil analysis of a sulfonylurea -by means of one of its transformation product- needs a previous study of the chemical reactivity of the sulfonylurea. This leads to the analysis procedures for the main soil metabolites of the sulfonylurea.     

裂化气、乙炔尾气及产品乙炔中H_2S、CS_2的测定

原料天然气常含有300mg/m~3以上的硫化氢、甲硫醇、乙硫醇、甲硫醚、乙硫醚等硫化物,经脱硫精制处理后,仍有少量硫化物转入到裂化气、尾气、产品乙炔中。这些硫化物的存在对甲醇合成触媒和醋酸乙烯合成触媒均有不利影响。因此,硫化物的检测对生产控制极为     

Novel Test System for Gas Sensing Materials and Sensors

Summary: A growing interest in gas sensors necessitates the requirement for a test system that is reliable and capable of handling multiple gas analytes at various concentrations. Most test systems currently used do not incorporate some type of standard with which to verify the actual concentrations of the gas analytes being tested, but rather calculate concentrations indirectly. The problem is that the calculated concentrations rarely take into account any loss that may occur across the test system. The test system described herein uses a specialized gas chromatograph (GC) that is capable of detecting down to the ppb range. It can either be used to screen potential sensing materials or to verify the actual concentration being tested for a specific sensor.     

体液中-叶萩碱检测方法的研究

本文报道了用气相色谱(GC)及气相色谱-质谱联用(GC/MS)检出人体液中一叶萩碱的方法.尿样经碱化后用乙醚直接萃取,回收率为72.1％;血浆样品用Sep-pak小柱提取,回收率为 43.9％,GC/MS的检测限为 20ng.方法快速、简便、准确.     

山楂挥发性化合物的气相色谱-质谱分析

采用蒸馏－萃取法收集山楂果的挥发性化合物,通过气相色谱及气相色谱／质谱分析,鉴定了３２种化合物,占总峰面积的６１％～６８％。其中主要的１０种化合物是顺－３－己烯醇、顺－３－乙酸己烯酯、α－萜品醇、糠醛、己醇、乙酸己酯、壬醛、柠檬醛、３－戊烯－２－酮,反－２－癸烯醛等。     

石油样品全二维气相色谱分析的分离特性

汽油、柴油等石油产品是典型的复杂混合物体系。一维气相色谱 (1DGC)分离能力不够 ,重叠十分普遍 ,定性不准确 ,族之间也不能分离干净。研究了全二维气相色谱 (GC×GC)用于石油样品分析的分离特性。对一特定的石脑油进行研究 ,一次进样实现了烷、环烷和芳烃 (PNA)的族分离。与 1DGC比较 ,GC×GC的正交分离、族分离、瓦片效应等特性使其峰容量大、灵敏度高、定性更简单准确 ,适合复杂混合物体系的分析 ,也是一种检测痕量杂质的有效手段。     

Rapid analysis of hydrocarbons and inert gases by a multidimensional gas chromatograph

A combination of a pressure switching system with multiple columns and photoionization detectors makes possible rapid analysis of a mixture of inorganic gases and hydrocarbons. Hydrocarbons are separated by a narrow bore capillary column. An alumina PLOT column is used for the separation of lower molecular weight hydrocarbons, especially C4 isomers, while a combination of a micro-packed column with Porapak N and a PLOT capillary column with Molecular Sieve 5A is used for the fast separation of inorganic gases. A photoionization detector is a powerful additional tool for organic gas analysis.