Chromatography and mass spectrometry

An important application of these results lies in the analysis of food flavorings using a combination of gas-phase chromatography and mass spectrometry (121, 122). Similarly, metabolic products of chlo-methiazole have been characterized (123). 

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... 

Fox, A., Morgan, S.L., Larsson, L., and Oldham, G., Analytical Microbiology Methods Chromatography and Mass Spectrometry, Plenum Press, New York, 1990. 

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],... 

To understand the need to interface liquid chromatography and mass spectrometry. 

To understand the requirements of an interface between liquid chromatography and mass spectrometry and the performance of the combined system. 

The combination of chromatography and mass spectrometry (MS) is a subject that has attracted much interest over the last forty years or so. The combination of gas chromatography (GC) with mass spectrometry (GC-MS) was first reported in 1958 and made available commercially in 1967. Since then, it has become increasingly utilized and is probably the most widely used hyphenated or tandem technique, as such combinations are often known. The acceptance of GC-MS as a routine technique has in no small part been due to the fact that interfaces have been available for both packed and capillary columns which allow the vast majority of compounds amenable to separation by gas chromatography to be transferred efficiently to the mass spectrometer. Compounds amenable to analysis by GC need to be both volatile, at the temperatures used to achieve separation, and thermally stable, i.e. the same requirements needed to produce mass spectra from an analyte using either electron (El) or chemical ionization (Cl) (see Chapter 3). In simple terms, therefore, virtually all compounds that pass through a GC column can be ionized and the full analytical capabilities of the mass spectrometer utilized. 

To understand the principles of operation of each of these interfaces, in particular with regard to the way in which they achieve compatibility between high performance liquid chromatography and mass spectrometry. 

The need for a more definitive identification of HPLC eluates than that provided by retention times alone has been discussed previously, as have the incompatibilities between the operating characteristics of liquid chromatography and mass spectrometry. The combination of the two techniques was originally achieved by the physical isolation of fractions as they eluted from an HPLC column, followed by the removal of the mobile phase, usually by evaporation, and transfer of the analyte(s) into the mass spectrometer by using an appropriate probe. 

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. 

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. 

GABA, heterocyclic analogues, 22 (1985) 67 GABAa receptor ligands, 36 (1999) 169 Gas-liquid chromatography and mass spectrometry, 12 (1975) 1 Gastric H /K -ATPase inhibitors, 31 (1994) 233... 

Li, S. and Dass, C., Iron(III)-Immobilized Metal Ion Affinity Chromatography and Mass Spectrometry for the Purification and Characterization of Synthetic Phosphopeptides, Anal. Biochem., 270, 9, 1999. 

Tjemberg, A., Edlund, P. O., and Noren, B., Screening of eltanolone metbolites in dog urine by anion-exchange/reversed phase liquid chromatography and mass spectrometry, /. Chromatogr. B, 715, 395, 1998. 

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

Analysis of Neuropeptides by Liquid Chromatography and Mass Spectrometry... 

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