LC-MS COMPATIBLE HPLC SEPARATION FOR XENOBIOTICS AND THEIR PHASE-I AND PHASE-II METABOLITES - SIMULTANEOUS ANION-EXCHANGE AND REVERSED-PHASE CHROMATOGRAPHY

Benzene and five of its mammalian metabolites, phenol, phenyl-beta-D-glucuronide, phenylsulfate, phenylmercapturate, and t,t-muconic acid, are separated on a methylstyrene-divinylbenzene-based anion exchange-reversed-phase column. The retention of the model compounds is manipulated by modifying the type, ionic strength, and pH of the mobile phase buffer, and the type and percent of organic mobile phase modifier. The separations developed are compatible with both particle beam (PB) and thermospray (TSP) interfaces used in liquid chromatography-mass spectrometry (LC-MS). These separations should be adaptable to the study of a wide range of xenobiotics and their phase I and phase II metabolites, and provide an LC-MS compatible alternative to the use of ion pairing reagents.