Liquid chromatographic analysis of di(2-ethylhexyl) phthalate: application to pharmacokinetic studies in the mongrel dog.

A high-performance liquid chromatographic (HPLC) assay was developed for the determination of di(2-ethylhexyl) phthalate (DEHP) in serum or plasma. Plasma DEHP concentrations that were measured by HPLC in specimens obtained from hemodialysis patients were in good agreement with corresponding concentrations that were measured by gas chromatography with selected ion monitoring (GC-SIM) (r2 = 0.996). Plasma DEHP concentrations were measured after intravenous DEHP administration (1.2-4.4 mg DEHP/kg body weight) to determine the effect of bilateral ureteral ligation on DEHP elimination in the mongrel dog. DEHP plasma clearance (approximately 6.3 ml/min/kg), steady-state distribution volume (approximately 0.21/kg), and terminal half-life (approximately 50 min) were unchanged in two dogs following bilateral ureteral ligation. DEHP terminal half-life and steady-state distribution volume were substantially smaller (25- to 70-fold) than reported previously in the rat or dog.