Metabolite identification biological matrix

Lopez, L.L. Yu, X. Cui, D. Davis, M.R. Identification of Drug Metabolites in Biological Matrixes by Intelligent Automated Liquid Chromatography/Tandem Mass Spectrometry, Rapid Commun. Mass Spectrom. 12(22), 1756-1760 (1998). 

The use of radiolabeled drugs is not only crucial for the quantification of unknown metabolites but has also long played a critical role in metabolite identification studies. The utility of radiolabeled substrates inelude (1) their use as tracers of drug-related components during sample elean-up, eoneentra-tion, profiling, and isolation from complex biological matrixes and (2) facilitation of LC-MS/MS detection of radiolabeled metabolites based on their HPLC retention times, peak shapes, and in some cases, isotopic ratios. 

To overcome the difficulties encountered with the bioassays and TLC methods, immunoassays using specific polyclonal and monoclonal antibodies have been developed for most of the major trichothecene mycotoxins and their metabolites.73 These antibodies have been used to produce simple, sensitive, and specific radioimmunoassays (RIAs) and enzyme-linked immunosorbent assays (ELISAs) for the mycotoxins. In the presence of the sample matrix, the lower detection limits for identification of trichothecene mycotoxins by RIA is about 2 to 5 ppb73 and by ELISA, 1 ppb.74 We conclude that immunoassays are useful tools for screening biomedical samples for evidence of a biological warfare attack with trichothecene mycotoxins. 

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