GLC assay of fenclorac in human plasma

A simple, sensitive GLC assay for fenclorac is described. Plasma proteins were precipitated with methanol, and the methanolic extract was refluxed with hydrochloric acid to form the methyl esters of fenclorac and the internal standard. The esters were purified by partitioning into benzene. Aliquots of 1 microliter of the concentrated benzene phase were injected into the gas chromatograph and quantitated by a 63Ni-electron-capture detector. Recovery of fenclorac from plasma averaged 82 +/- 1.6%.