Simultaneous Determination of Trimethoprim and Diaveridine in Tissues of Chicken, Porcine, and Fish by Hydrophilic Interaction Liquid Chromatography-Tandem Mass Spectrometry

A sensitive liquid chromatography-tandem mass spectrometry method for simultaneous determination of trimethoprim and diaveridine in edible tissue samples (chicken and porcine muscle; liver, kidney, and fat tissues as well as fish muscle) was developed and validated in this study. Trimethoprim, diaveridine, and the internal standard trimethoprim-D-3 were extracted from samples using acetonitrile. The Oasis MCX Solid-Phase Extraction Cartridge was selected for cleaning up the extracts. Chromatographic separation was performed on a hydrophilic interaction liquid chromatography column with gradient elution. The analytes were determined using triple-quadrupole mass spectrometry in positive electrospray ionization and multiple reaction monitoring mode. The relative recoveries from spiked samples ranged from 82.5 to 117.2 %, with the relative standard deviations generally being below 15.4 %. Limits of detection and quantification for analytes were within 0.3-1 and 1-2 mu g kg(-1), respectively. The proposed method was successfully applied to detect trimethoprim and diaveridine in real samples.