title: A rapid gas chromatographic method for the determination of chlorophenoxyisobutyric acid in plasma and urine.
abstract: A rapid gas chromatographic method is described for the determination of chlorophenoxyisobutyric acid (the active metabolite of clofibrate) in plasma and urine. The assay involves an extraction into toluene and back-extraction of the chlorophenoxyisobutyric acid and the internal standard (2-naphthoic acid) into the methylating reagent (trimethylanilinium hydroxide). Concentrations of 1 mug/ml in plasma and urine can easily be measured; the precision of the method is 3.3 +/- 0.7% for plasma and 2.7 +/- 0.4% for urine. There is no interference from endogenous compounds or from drugs commonly prescribed together with clofibrate.
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D002994:Clofibrate / Q000031:analogs & derivatives* / Q000097:blood / Q000652:urine; D006358:Hot Temperature; D006801:Humans; D013997:Time Factors
chemical_list: D002994:Clofibrate