HPLC assay for characterizing alpha-cyano-3-phenoxybenzyl pyrethroids hydrolytic metabolism by Helicoverpa armigera (Hubner) based on the quantitative analysis of 3-phenoxybenzoic acid.

A new HPLC assay for characterizing the hydrolytic metabolism of alpha-cyano-3-phenoxybenzyl pyrethroids in Helicoverpa armigera (Hubner) through quantitative analysis of the common metabolite 3-phenoxybenzoic acid (3-PBA), converted from 3-phenoxybenzaldehyde (3-PBAld) by aldehyde-oxidizing enzymes, has been established. The method was validated by measuring beta-cypermethrin metabolism in H. armigera. The hydrolytic activity based on 3-PBA toward beta-cypermethrin was consistent with that based on (trans+cis)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA). The analysis system is based on using liquid-liquid extraction and HPLC with a C18 column, gradient elution, and UV detection at 230 nm. The analytical methodology was validated by its repeatability, linearity, accuracy, and limits of detection. The developed and validated HPLC assay method was applied to examine the inhibition effect of S,S,S-tributyl phosophorotrithioate (DEF) and piperonyl butoxide (PBO) on beta-cypermethrin hydrolytic metabolism, and to evaluate the inducibility of six alpha-cyano-3-phenoxybenzyl pyrethroids hydrolytic metabolism by 2-tridecanone, a generalized "inducer" of detoxifying enzyme activities.