Gas chromatography—Fourier transform infrared spectroscopy—mass spectrometry. A powerful tool for component identification in complex organic mixtures

Fourier transform infrared spectrometry (FTIR) and mass spectrometry (MS) have been combined with gas chromatography (GC) for the identification of eluted components in a complex mixture. The combined technique, GC—FTIR—MS, provides simultaneous GC—FTIR and GC—MS data from a single injection.     

应用GC/FTIR鉴定一些单萜类化合物的研究

本文介绍毛细管GC/IR方法鉴定a-蒎烯在固体酸Nafion H催化下酯化及重排异构化的产物. 讨论了GC/IR方法定性的可靠性及存在的问题, 并对GC/IR实验方法, 作了较为详细的研究, 其中包括不同口经毛细管色谱柱与光管匹配问题和影响红外检测灵敏度的多种因素.     

Polychlorobiphenyls differentiation and identification by gas chromatography/fourier transform infrared spectroscopy

Reference infrared vapour phase spectra of 20 polychlorobiphenyls (PCBs) have been obtained by gas chromatography/Fourier transform infrared spectroscopy (GC/FTIR). These spectra are consistent with those of PCB obtained by diffuse reflectance IR spectroscopy (DRIFT) and with those of more simple molecular structures (iodochlorobenzenes, 1-bromodichlorobenzenes). The IR frequencies of the GC/FTIR spectra of PCB are assigned in terms of substitution patterns. This work shows that GC/FTIR can be a good approach for differentiation and identification of PCB in complex mixtures.     

变径毛细管柱GC／FTIR联用技术的研究

本文介绍了使用新型变径毛细管柱的气相色谱/傅里叶变换红外光谱联用技术(GC/FTIR)。以正构烷烃的混合物为样品,研究了载气速流、色谱进样量及柱后死体积对联用效果的影响。分别在变径毛细管柱GC/FTIR和普通毛细管柱GC/FTIR联用系统上分析了烷烃芳烃混合物和合成汽油样品,并利用软件系统提供的程序和红外标准谱库对所得光谱进行了检索。实验结果表明,变径毛细管柱GC/FTIR系统具有色谱进样量大,可鉴定组分多,分离能力强和检测灵敏度高等显著优点。     

多种气相色谱联用技术分析陕西刺五加茎挥发油的化学成分

采用气相色谱/四极杆质谱(GC/qMS)、气相色谱/正交加速飞行时间质谱(GC/oaTOFMS)和气相色谱/傅里叶变换红外光谱(GC/FTIR)联用技术,对一种陕西产刺五加Acanthopanax senticosus (Rupr. et Maxim.) Harms茎挥发油的化学成分进行了分析。基于GC/qMS谱库的检索功能,结合GC/FTIR在结构鉴别上的优势和GC/oaTOFMS对质谱碎片离子精确的质量测定功能,成功地实现了对68个色谱组分的定性分析。与使用单一的联用技术(例如GC/qMS)相比,利用多种色谱联用技术在定性分析上的互补性,可以明显提高对组成复杂的挥发油类样品分析的可靠性。     

傅里叶变换红外光谱和气相色谱-质谱法快速检测鼠药

用傅里叶变换红外光谱(FT-IR)差谱技术和气相色谱．质谱(GC/MS)全扫描法及特征离子监测技术，建立了毒鼠强和氟乙酰胺的标准质谱图库。利用有机溶剂直接萃取与FT-IR和GC/MS的结合，建立了混合组分原形物中毒鼠强和氟乙酰胺的快速检测方法。对7份实际样品的鉴定获得满意的结果。建立的方法为侦破案件提供了快速、灵敏、准确、有效的分析手段。     

FTIR及Py-GC/MS定性分析高聚物单体

红外光谱反应出的是特征化学基团的振动 ,对于高聚物的具体单体组成分析 ,只能借助于紫外光谱、核磁共振及质谱进行综合判断才能得到圆满的鉴定结果[1,2 ] 。本工作针对在红外光谱仪不能分辨的情况下通过气相色谱 质谱联用技术进行综合分析鉴定 ,结果可为其它高聚物分析研究提供实验依据。1　实验1 1　仪器及试验条件未知高聚物试样为白色颗粒状 (晨光化工二厂 )。ＳＹＳＴＥＭ2 0 0 0ＦＴＩＲ ,ＰＥ公司造ＩＲ谱仪 ;ＣＤＳ2 0 0 0铂金丝裂解器 ,裂解室温度 2 5 0℃ ,裂解温度 6 0 0℃ ,升温速率 1 40℃ ｍｓ;ＨＰ6 890型 ,Ｃｏｍｐｏｎｄ…     

Analysis of the volatile oil from the stem of Acanthopanax Senticosus (Rupr. et Maxim.) harms with several hyphenated methods of chromatography

Gas chromatography/quadrupole mass spectrometry (GC/qMS), gas chromatography/Fourier transform infrared spectrometry (GC/FTIR) and gas chromatography/orthogonal acceleration time-of-flight mass spectrometry (GC/oaTOFMS) were applied to analyze the volatile oil from the stem of Acanthopanax Senticosus (Rupr. et Maxim.) Harms. Based on the mass spectra search function of GC/qMS with the aid of the discriminability of the geometrical isomer by GC/FTIR and the ability to determine the accurate mass charge ratio (m/z) by GC/oaTOFMS, 68 GC eluants were identified successfully. Compared with the results obtained by GC/qMS only, the analytical results obtained by these hyphenated methods of gas chromatography are more credible. __________ Translated from Chinese Journal of Chromatography, 2005, 23(2)(in Chinese)     

不分流进样/Cu~(2 )预柱-毛细柱GC/FTIR鉴定环境水中痕量有机污染物

本文介绍一种新的分离分析技术,即不分流进样/Cu~(2 )预柱-毛细柱GC/FTIR,它能彻底消除溶剂影响,实现大容量进样,系统灵敏度比现行GC/FTIR系统高约1～2个数量级。这种技术已成功地用于长江水中痕量有机污染物的分析。     

Pyrolysis-gas chromatography/fourier-transform infrared spectrometry of poly(ester urethane) elastomers

Three types of industrial poly (ester urethane) elastomers were studied by Curie–point pyrolysis–gas chromatography/Fourier–Transform infrared spectrometry (Py–GC/FTIR) with a maximum pyrolysis temperature of 973 K. The samples chosen were the Urepans 600 and 641 from Bayer and Elastollan C 78 A from BASF/Elastogran. The poly(ester urethane) elastomers are composed of three units: a polyesterdiol, a short chain diol and a diisocyanate. Py–GC/FTIR allows a rapid and unambiguous identification of the polymer chains by key fragments.     

Multilevel profiling and identification of Dalbergia odorifera and Dalbergia stevensonii by FTIR,NMR and GC/MS

Chemical differences of the extractives revealed by FTIR methods can be further confirmed by ¹H NMR and ¹³C NMR. Meanwhile, the volatile compounds in the extractives can be identified by GC/MS     

Individual determination of ortho and non-ortho substituted polychlorobiphenyls (PCBs) in sediments by high performance liquid chromatographic pre-separation and gas chromatography/ECD detection

Summary An analytical procedure for the individual determination of ortho and non-ortho PCB congeners in sediments, using high performance liquid chromatography (HPLC) preseparation and gas chromatography/ECD detection, is described. Gas chromatography/FTIR spectrometry (GC/FTIR) and gas chromatography/mass spectrometry (GC/MS) were employed for individual congener identification and determination. Sample extraction, clean-up of extract and selective elution procedures were optimized by using reference certified marine sediment samples. Recovery and precision were typically 83% and 16% respectively at 2 ng/g of total PCB content. The proposed procedure, tested by analyzing real sediment samples, showed a reproducibility better than 20% at 13 ng/g PCB level.     

鱼油中二十碳五烯酸和二十二碳六烯酸的气相色谱—红外光谱分析

本文利用气相色谱－红外光谱联用仪对鱼油中的ＥＰＡ和ＤＨＡ进行了定性，定量的分析研究，建立了ＥＰＡ－Ｅ和ＤＨＡ－Ｅ的蒸气相红外标准谱图和气相色谱保留时间数据库，提供了一种在无法找到标准物质的情况下鱼油中ＥＰＡ和ＤＨＡ进行定性，定量分析的简便准硼确的方法。     

Determination of ethers and alcohols in reformulated gasolines by gas chromatography/atomic emission detection

A GC method for the determination of oxygenated additives in reformulated gasolines (RFG) is described. The method uses on-column injection and atomic emission selective detection of oxygenates using the 777 nm NIR emission line. Detection limits are approximately 10 ppm oxygen. Results compared well with other techniques, such as GC/FTIR.     

Effects of a Surfactant on the Electrocatalytic Activity of Cobalt Hexacyanoferrate Modified Glassy Carbon Electrode Towards the Oxidation of Dopamine

The cobalt hexacyanoferrate film (CoHCF) was deposited on the surface of a glassy carbon (GC) electrode with a potential cycling procedure in the presence and absence of the cationic surfactant, cetyl trimethylammonium bromide (CTAB), to form CoHCF modified GC (CoHCF/GC) electrode. It was found that CTAB would affect the growth of the CoHCF film, the electrochemical behavior of the CoHCF film and the electrocatalytic activity of the CoHCF/GC electrode towards the electrochemical oxidation of dopamine (DA). The reasons of the electrochemical behavior of CoHCF/GC electrode influenced by CTAB were investigated using FTIR and scanning electron microscope (SEM) techniques. The apparent rate constant of electrocatalytic oxidation of DA catalyzed by CoHCF was determined using the rotating disk electrode measurements.     

Identification of amphetamine isomers by GC/IR/MS

The methods of gas chromatography/Fourier transform infrared spectroscopy (GC/FTIR) and gas chromatography/infrared spectroscopy/mass spectrometry (GC/IR/MS) are evaluated for their ability to differentiate side chain isomers of amphetamine. It is found that absorption bands from 3000 to 2850 cm-1 and 900 to 650 cm-1 are most useful for differentiating the alkyl amines, while the bands from 1600 to 900 cm-1 are only useful for differentiating primary amines from the other substituted amines. The combination of GC/IR/MS is superior for differentiating these side chain isomers.     

Compositional studies of high-temperature coal tar by GC/FTIR analysis of light oil fractions

Summary A method for determination of the composition of the light oil fractions in high-temperature coal tar by means of distillation, followed by gas chromatography on a crosslinked fused-silica, capillary column coated with optimum amount of stationary phase and identification by capillary gas chromatography/Fourier transform infrared spectrometry combined with GC retention indices (GC/FTIR-RI) is described. This method was effectively used to identify complex mixture such as coal tar without any standard samples, especially, adapted for isomeric compounds. More than 60 and 50 compounds were also separated and identified respectively in light oil fractions. This shows the capability of the capillary GC/FTIR combined with GC retention indices to identify isomers not accomplished by GC/MS.     

玻璃芯毛细管柱的研制

介绍了含玻璃内芯的新型毛细管色谱柱的制备方法,以正癸烷和正庚烷为测试物,测定了这种柱子的柱效率和柱容量,并与普通玻璃毛细管柱进行了比较。结果表明,所制玻璃芯毛细管柱的柱效率和柱容量均优于普通毛细管柱。用玻璃芯毛细管柱及使用这种柱子的GC/FTIR联用系统分别分析了烷芳烃混合物和合成汽油样品,取得了满意的结果。     

裂解气相色谱－红外光谱联用分析聚合物结构（Ⅱ）

采用国产ＳＣ－７型色谱仪及ＪＰ－０１型居里点裂解器、Ｎｉｃｏｌｅｔ１７０ＳＸ红外光谱仪及接口组成的裂解气相色谱－傅里叶变换红外光谱（ＰＧＣ／ＦＴＩＲ）分析仪、ＨＰ－１７型大口径毛细管色谱柱，分析了两个复杂组成的聚合物样品。从主要裂解碎片峰的定性结果及形成机理出发，逐步推出了原样品的组成和结构。常规红外光谱分析方法被用来作为对比，但它获得的信息有限，无法得到能与ＰＷＢＣＧＣ／ＦＴＩＲ分析结果相媲美的结论，充分显示了ＰＷＢＣＧＣ／ＦＴＩＲ用于聚合物分析的优越性。     

Determination of total <Emphasis Type="Italic">trans</Emphasis> fats and oils by infrared spectroscopy for regulatory compliance

The mandatory requirement in many countries to declare the amount of trans fat present in food products and dietary supplements has led to a need for sensitive and accurate methodologies for the rapid quantitation of total trans fats and oils. Capillary gas chromatography (GC) and infrared spectroscopy (IR) are the two methods most commonly used to identify and quantify trans fatty acids for food labeling purposes (see the article by Delmonte and Rader in this ABC issue for a detailed presentation of GC methodology). The present article provides a comprehensive review of the IR technique and the current attenuated total reflection (ATR) Fourier-transform (FT) IR methodologies for the rapid determination of total trans fats and oils. This review also addresses potential sources of interferences and inaccuracies in FTIR determinations, particularly those done at low trans levels. Recent observations have shown that the presence of saturated fats caused interferences in the FTIR spectra observed for trans triacylglycerols. The recognition and resolution of previously unresolved quantitative issues improved the accuracy and sensitivity of the FTIR methodology. Once validated, it is anticipated that the new negative second-derivative ATR-FTIR procedure will make IR spectroscopy more suitable than ever, and a rapid alternative and/or complementary method to GC, for the rapid determination of total trans fats for regulatory compliance. Figure Infrared light bouncing inside an internal reflection crystal