Biological Reactive Intermediates III

Abstract

Kocsis, J. J.; Snynder, R.; Vainio, H.; Eds.; Plenum Press: New York, 1977; p 314. Fukoto, T. R.; Fahmy, M. A. H. Organic thiophosphate agricultural chemicals, such as malathion, parathion, and others, can be satisfactorily analyzed by the newer method of high-performance liquid chromatography (HPLC) with on-line photolysis (hv), followed by electrochemical detection (EC) using single-or dual-electrode approaches for the species generated. This approach, HPLC-hv-EC, has been applied to about 20 different thiophosphates, most of which are widely used agriculturally and for which trace residue levels are routinely monitored. Dual-electrode response ratios have been determined for all of these analytes, along with minimum detection limits (MDLs) in many cases. These approaches can also be used for the quality control evaluation of commercial formulations by flow injection analysis (FIA) with hv-EC and no HPLC separations. Wheat middling extracts have been analyzed by the commonly used gas chromatography (GC) flame photometric detection (FPD) method of residue analysis, as well as by HPLC-hv-EC. These comparative studies indicate that the newer method is reproducible, accurate, precise, and entirely reliable. Standard additions have been applied to wheat middling extracts, and the quantitative results are compared with the external standard method.