Doping-control analysis of 14 diuretics in animal-derived foods using ultra-high-performance liquid chromatography-tandem mass spectrometry

A rapid, sensitive, and confirmatory method was developed and validated for the determination of 14 diuretics in multiple animal-derived foods using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Analytes were extracted from samples using acetonitrile containing 0.1% formic acid (FA) and then purified and concentrated using an Oasis PRIME HLB cartridge. The extraction and purification as well as the chromatographic and MS conditions were investigated to increase sample throughput and sensitivity. Quantification was performed using MS/MS with an electrospray ionization source in the positive multiple reaction monitoring (MRM) mode. The overall recoveries ranged from 60.8 to 116.4% with intra-day and inter-day relative standard deviation lower than 11.8% and 12.2%, respectively. The limits of quantitation for different matrices (pork, beef, lamb, milk, and eggs) were between 0.53 and 2.43 μg/kg, which were satisfactory for surveillance monitoring. The proposed method can be used to provide additional information for the reliable risk assessment of foodborne doping.