Determination of Sulfadimethoxine, Sulfamethoxazole, Trimethoprim and Their Main Metabolites in Lung and Edible Tissues from Pigs by Multi-Dimensional Liquid Chromatography

Abstract

A practically fully automated liquid chromatographic method was developed in order to investigate the tissue distribution of sulfadimethoxine, sulfamethoxazole, trimethoprim and their main metabolites in lung tissue and edible tissues from pigs. The sample pre-treatment consisted of a simple extraction with an aqueous buffer solution. The filtered extract was injected onto a liquid chromatographic system which consisted of an on-line gel- permeation column, a small preconcentration column and an analytical HPLC column. Parent drugs and metabolites were separated by reversed-phase HPLC and detected by UV absorption. Recoveries of parent compounds and their metabolites in spiked lung, muscle, kidney and liver tissue were constant and varied between tissues from 60-85 %. Detection limits in these tissues were 10-50 ng/g tissue. Application of the method for the analysis of drug residues in tissue samples obtained from treated pigs is described.