LAUSR

Abstract The improper use of diuretics in veterinary practices may lead to their presence in animal-derived foods, which could cause the inadvertent poisoning of consumers and doping of athletes that consume these contaminated products. Herein, we describe the analytical method that we developed to monitor diuretic residues in foods, which comprises an optimized, modified QuEChERS pre-treatment technique and subsequent high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) analysis. This method was employed to simultaneously analyze seven diuretics in 120 animal-derived food samples, which included porcine muscle, bovine muscle, lamb muscle, rabbit muscle, milk, and eggs. The method included 2 g of each animal-derived food samples with 15 mL acetonitrileand 2.0 g of anhydrous sodium sulfate for extracting. After vortex and centrifugation, the resulting liquid was purified using primary secondary amine (100 mg), octadecylsilane (100 mg), and MgSO4 (600 mg). Under optimal conditions, the limits of quantitation were lower than 2 μg/kg for all analytes. The recoveries were in the range of 72.1–118.1 % at three fortified levels with relative standard deviations of less than 17.3 %. All the tested samples showed negative results for the diuretics.