Gas chromatography and mass

Kitson, F. G. Larsen, B. S. McEwen, G. N. Gas Chromatography and Mass Spectrometry A Practical Guide. Academic Press San Diego, 1996. 

GC/MS. gas chromatography and mass spectrometry used as a combined technique... 

Py/GC/MS. pyrolysis, gas chromatography, and mass spectrometry used as a combined technique Py/MS. pyrolysis and mass spectrometry used as a combined technique oa-TOF. orthogonally accelerated time of flight Q. quadrupole field or instrument... 

Kitson, F.G., Larsen, B.S., and McEwen, C.N., Gas Chromatography and Mass Spectrometry, Academic Press, New York, 1996. 

Impurities in hydrocarbons can be characterised and evaluated by gas chromatography and mass spectrometry. The total amount of impurities present can be estimated from the thermometric freezing curve. 

A large number of silylating agents exist for the introduction of the trimethylsilyl group onto a variety of alcohols. In general, the sterically least hindered alcohols are the most readily silylated, but are also the most labile to hydrolysis with either acid or base. Trimethylsilylation is used extensively for the derivatization of most functional groups to increase their volatility for gas chromatography and mass spectrometry. 

Thermogravimetric analysis has also been used in conjunction with other techniques, such as differential thermal analysis (DTA), gas chromatography, and mass spectrometry, for the study and characterisation of complex materials such as clays, soils and polymers.35... 

Maximum benefit from Gas Chromatography and Mass Spectrometry will be obtained if the user is aware of the information contained in the book. That is, Part I should be read to gain a practical understanding of GC/MS technology. In Part II, the reader will discover the nature of the material contained in each chapter. GC conditions for separating specific compounds are found under the appropriate chapter headings. The compounds for each GC separation are listed in order of elution, but more important, conditions that are likely to separate similar compound types are shown. Part II also contains information on derivatization, as well as on mass spectral interpretation for derivatized and underivatized compounds. Part III, combined with information from a library search, provides a list of ion masses and neutral losses for interpreting unknown compounds. The appendices in Part IV contain a wealth of information of value to the practice of GC and MS. 

Gas Chromatography and Mass Spectrometry A Practical Guide is designed to be a valuable resource to the GC/MS user by incorporating much of the practical information necessary for successful GC/MS operation into a single source. With this purpose in mind, the authors have kept the reading material practical and as brief as possible. This guide should be immediately valuable to the novice, as well as to the experienced GC/MS user who may not have the breadth of experience covered in this book. 

The carbon number distribution of technical secondary alkanesulfonates determined by pyrolysis gas chromatography and mass spectrometry (GC-MS) is shown in Fig. 13 together with the corresponding carbon number pattern of the raw material paraffins obtained by GC [16]. Pyrolysis was performed in a crucible-modified SGE pyrojector after covering the mixture with quartz wool. The presence of up to 10 wt % of disulfonates in technical alkanesulfonates is demonstrated by fast atom bombardment and mass spectrometry (FAB-MS) (Fig. 14) [24],... 

An environmental protocol has been developed to assess the significance of newly discovered hazardous substances that might enter soil, water, and the food chain. Using established laboratory procedures and C-labeled 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD), gas chromatography, and mass spectrometry, we determined mobility of TCDD by soil TLC in five soils, rate and amount of plant uptake in oats and soybeans, photodecomposition rate and nature of the products, persistence in two soils at 1,10, and 100 ppm, and metabolism rate in soils. We found that TCDD is immobile in soils, not readily taken up by plants, subject to photodecomposition, persistent in soils, and slowly degraded in soils to polar metabolites. Subsequent studies revealed that the environmental contamination by TCDD is extremely small and not detectable in biological samples. 

Cole WJ, Mitchell RG, Salamonsen RF. 1975. Isolation, characterization and quantitation of chloral hydrate as a transient metabolite of trichloroethylene in man using electron gas capture gas chromatography and mass fragmentography. J Pharm Pharmacol 27 167-171. 

Baser H-R, MD Muller (1993) Enantioselective determination of chlordane components, metabolites, and photoconversion products in environmental samples using chiral high-resolution gas chromatography and mass spectrometry. Environ Sci Technol 27 1211-1220. 

F.G. Kitson, B.S. Larsen and C.N. McEwen, Gas Chromatography and Mass Spectrometry. A Practical Guide, Academic Press, San Diego, CA (1996). 

Leenheers, L.H., Breugel, D.G., Ravensberg, J.C., Meuling, W.J.A., and Jongen, M.J.M. (1992) Determination of 2-isopropoxyphenol in urine using capillary gas chromatography and mass-selective detection, ]. Chromatography, 578 189-194. 

The conventional approach to solvent extraction is the batch method. Early work with this method was hampered by the low concentration of the compounds present and the relative insensitivity of the methods of characterization. Thus lipids and hydrocarbons have been separated from seawater by extraction with petroleum ether and ethyl acetate. The fractionation techniques include column and thin-layer chromatography with final characterisation by thin-layer chromatography, infrared, and ultra-violet spectroscopy and gas chromatography. Of these techniques, only gas chromatography is really useful at levels of organic matter present in seawater. With techniques available today such as glass capillary gas chromatography and mass spectrometry, much more information could be extracted from such samples [20]. 

Behavioral bioassays are inextricably linked with chemical studies to decipher the information content of olfactory signals (Albone 1984). As a complement to the experimental approach described above, several research groups have applied chemical approaches, particularly gas chromatography and mass spectrometry (GC-MS),... 

The asterisked analyses were carried out by a combination of gas chromatography and mass spectrometry. 

Kester [5] has discussed the application of the purge and trap gas chromatographic method to the determination of aliphatic chloro-compounds in soil. Following methanol extraction of the soil the extract is gas purged and the purge gases trapped on a Tenax silica gel/ charcoal trap followed by thermal desorption from the trap and examination by gas chromatography and mass spectrometry. Compounds that have been determined by this method are listed in Table 5.1. 

McMurtrey et al. [65] investigated the feasibility of determining polychlorinated biphenyls adsorbed on sediments by a procedure involving pyrolytic desorption at 1000°C, followed by gas chromatography and mass spectrometry. The procedure was capable of detecting polychlorinated biphenyl in sediment at the lOmg kgy1 level. 

Alford Stevens et al. [49] have reported on an inter-laboratory study of the determination of polychlorinated biphenyls in environmental sediments. Electron capture gas chromatography and mass spectrometry were used to identify and determine polychlorinated biphenyls. For electron capture, an overall standard deviation of 30% was achieved while mass spectrometry gave 38%. 

Bianchi AP, Varney MS. 1993. Sampling and analysis of volatile organic compounds in estuarine air by gas chromatography and mass spectrometry. J Chromatogr 643(l) 11-23. 

Structure elucidation of semiochemicals by modern NMR-techniques (including HPLC/NMR) is often hampered by the very small amounts of available material and problems in the isolation of pure compounds from the complex mixtures they are embedded in. Thus, the combination of gas chromatography and mass spectrometry, GC/MS, is frequently the method of choice. Determination of the molecular mass of the target compound (by chemical ionisation) and its atomic composition (by high resolution mass spectrometry) as well as a careful use of MS-Ubraries (mass spectra of beetle pheromones and their fragmentation pattern have been described [27]) and gas chromatographic retention indices will certainly facihtate the identification procedure. In addition, the combination of gas chromatography with Fourier-transform infrared spec-... 

Other methods for the determination of aromatics in naphtha include a method (ASTM D5580) using a flame ionization detector and methods that use combinations of gas chromatography and Fourier transform infrared spectroscopy (GC-FTIR) (ASTM D5986) and gas chromatography and mass spectrometry (GC-MS) (ASTM D5769). 

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