title: Determination of trimethoprim metabolites including conjugates in urine using high-performance liquid chromatography with combined ultraviolet and electrochemical detection.
abstract: A high-performance liquid chromatographic method for the determination of trimethoprim metabolites in pig urine was developed. The metabolites-glucuronic acid and sulphuric acid conjugates of phenolic metabolites formed by demethylation of trimethoprim-were quantitated after treatment of urine with beta-glucuronidase (Escherichia coli). The sulphuric acid conjugate was not susceptible to enzymatic hydrolysis and was therefore assayed as the conjugate by use of ion-pair chromatography on the reversed-phase column. In order to find suitable conditions for enzymatic hydrolysis of the glucuronides, the conjugates were obtained by gel chromatography of urine from a [14C] trimethoprim-treated pig.
mesh_terms: D000818:Animals; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004563:Electrochemistry; D005965:Glucuronates / Q000652:urine; D006868:Hydrolysis; D010084:Oxidation-Reduction; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013552:Swine; D014295:Trimethoprim / Q000652:urine*
chemical_list: D005965:Glucuronates; D014295:Trimethoprim