Coupled beta-cyclodextrin and reverse-phase high-performance liquid chromatography for assessing biphenyl hydroxylase activity in hepatic 9000g supernatant.

Coupled beta-cyclodextrin bonded-phase and reverse-phase high-performance liquid chromatography with fluorescence detection has been employed to detect the major hydroxylated metabolites of biphenyl following in vitro incubation with hepatic 9000g supernatant. The method requires only 0.3 mg of protein and its sensitivity was as low as 0.36 nmol metabolite formed/mg protein/h (0.32 pmol injected) for 2-, 3-, and 4-hydroxybiphenyl. Microsomes need not be purified and no organic extraction or derivatization was required. The method was employed successfully with samples from rats and mice treated with Aroclor, beta-naphthoflavone, or phenobarbital; from monkeys dosed with Aroclor; and from untreated dogs.