Mass spectrometric analysis organic compounds

The analyte must be converted into a volatile compound suitable for mass-spectrometric analysis. Procedures for C, N, and O follow those developed for conventional organic microanalysis— oxidation of organic C to COj, reduction of organic N to N2, and conversion of O2 into CO or COj. In most procedures, cryogenic purification of the products is carried out before mass spectrometry, and both off-line and on-line procedures have been developed. 

Principles and Characteristics Mass-spectral analysis methods may be either indirect or direct. Indirect mass-spectral analysis usually requires some pretreatment (normally extraction and separation) of the material, to separate the organic additives from the polymers and inorganic fillers. The mass spectrometer is then used as a detector. Direct mass-spectrometric methods have to compete with separation techniques such as GC, LC and SFC that are more commonly used for quantitative analysis of polymer additives. The principal advantage of direct mass-spectrometric examination of compounded polymers (or their extracts) is speed of analysis. However, quite often more information can be... 

Rieley, G. (1994) Derivatization of organic compounds prior to gas chromatographic combustion isotope ratio mass spectrometric analysis identification of isotope fractionation processes. Analyst 119, 915 919. 

CO2 is the gas generally used for mass-spectrometric analysis. More recently CO and O2 have also been used in high temperature conversion of organic material and in laser probe preparation techniques. A wide variety of methods have been described to liberate oxygen from the various oxygen-containing compounds. 

Yokouchi, Y H. Bandow, and H. Akimoto, Development of Automated Gas Chromatographic-Mass Spectrometric Analysis for Natural Volatile Organic Compounds in the Atmosphere, J. Chromatogr., 642, 401-407 (1993). 

Rosel I, A., Gomez-Behnehon, J.L, and Grimalt, J.O., Gas Chromatographic-Mass Spectrometric Analysis of Urban-Related Aquatic and Airborne Volatile Organic Compounds Study of the Extracts Obtained by Water Closed-Loop Stripping and Ah Adsorption with Charcoal and Polyurethane Foam, Journal of Chromatography. Biomedical Applications, Vol. 562, p 493-506. 1991. 

Mass spectrometry is a standard spectroscopic technique for the characterisation of high molecular weight organic and inorganic compounds, but has until recently received little attention from the zeolite community. The surface composition of zeolites has been explored using fast atom bombardment mass spectrometry (FABMS)[66] and secondary ion mass spectrometry [67], but mass spectrometric analysis of the bulk composition of a zeolite or of adsorbed molecules has not until very recently been attempted. The practical difficulty is to vaporise the solid. Two different strategies have been proposed laser ablation and plasma desorption. 

Solid-probe mass spectrometric analysis (31) showed that the benzene-ether extracts consist mainly of organic acids. Therefore, these extracts were deriva-tized with dimethylsulfate-de to yield methyl-da-labeled derivatives. The derivatives were analyzed by GCMS and high resolution MS using techniques that have been described previously (31). Authentic samples of phenolic acids deriva-tized with dimethylsulfate-dg or diazomethane were also analyzed by GCMS for reference. The distribution of the organic acids as methyl esters was determined by measuring areas of GC fiame ionization detector peaks with a correction for the effective carbon number for each compound. 

Anderson, D.M., Orgel, L.E., Oro, J., Owen, T., Shulman, G.P., Toulmin, P.and Urey, H.C., 1972. Mass spectrometric analysis of organic compounds, water and volatile constituents in the atmosphere and surface of Mars. Icarus, 16 111-38. 

Spectrometric Analysis. Remarkable developments ia mass spectrometry (ms) and nuclear magnetic resonance methods (nmr), eg, secondary ion mass spectrometry (sims), plasma desorption (pd), thermospray (tsp), two or three dimensional nmr, high resolution nmr of soHds, give useful stmcture analysis information (131). Because nmr analysis of or N-labeled amino acids enables determiaation of amino acids without isolation from organic samples, and without destroyiag the sample, amino acid metaboHsm can be dynamically analy2ed (132). Proteia metaboHsm and biosynthesis of many important metaboUtes have been studied by this method. Preparative methods for labeled compounds have been reviewed (133). 

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