โ Scribed by S.B. Turnipseed; A.J. Allentoff; J.A. Thompson
No coin nor oath required. For personal study only.
Qualitative and quantitative determinations of hydroperoxides are of central importance in many areas of biochemical research, but analysis of intact hydroperoxides by capillary gas chromatography-mass spectrometry (GC-MS) generally has not been possible due to the thermal instability of these compounds. It is demonstrated here that structurally diverse hydroperoxides can be converted to trimethylsilyl (TMS) peroxides and analyzed by GC-MS without significant thermal decomposition. The hydroperoxides investigated in this report include cumyl hydroperoxide, 2-phenylethylhydroperoxide, 13-hydroperoxy-octadeca-9,11-dienoic acid, 2,6-di-tert-butyl-4-hydroperoxy-4-methylcyclohexadienone (BHTOOH), and 2,4,6-trimeth-yl-4-hydroperoxycyclohexadienone (TMPOOH). A representative peracid, 3-chloroperoxybenzoic acid, was successfully analyzed as its TMS peroxyester. Chromatographic and mass spectral characteristics of the TMS peroxides and their corresponding TMS ethers were obtained and compared with thermospray HPLCMS data for underivatized hydroperoxides. The utility of the GC-MS assay for quantitating low levels of hydroperoxides in biological matrices was demonstrated by measuring BHTOOH and TMPOOH formed during the NADPH-dependent oxidation of alkylated phenols by rat liver microsomes. Overall, the results demonstrate that the advantages of GC--MS analysis (i.e., high chromatographic resolution, quantitative precision, high sensitivity, and the acquisition of structural information) can be applied successfully to intact hydroper-
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Gas chromatographyfion-trap mass spectrometry in the electron ionization (EI) mode, with a cooled temperature-programmable injector, has been used for the analysis of a series of thermolabile carbamate and phenylurea pesticides. The mass spectra were found to be in good agreement with 70eV solid-pro