Simultaneous determination of nine anticoagulant rodenticides by ultra-performance liquid chromatography–tandem mass spectrometry with ultrasound-assisted low–density solvent dispersive liquid–liquid microextraction

A sensitive determination method is developed for nine anticoagulant rodenticides (ARs) in urine samples by ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) with ultrasound-assisted low–density solvent dispersive liquid-liquid microextraction (UA–LDS–DLLME) pretreatment. The target analytes are brodifacoum, bromadiolone, warfarin, coumachlor, coumatetralyl, difenacoum, pindone, diphacinone and chlorophacinone. The parameters that influence the extraction recovery in the UA–LDS–DLLME were systematically investigated and optimized. With the optimized extraction parameters, recoveries ranging from 64.6%–124.2% were obtained for the target analytes. The linear range for all analytes was 0.1–100 ng/mL with correlation coefficients higher than 0.99. Very low LODs ranging in 0.003–0.03 ng/mL were obtained. LOQs were in the range of 0.01–0.1 ng/mL for the nine target analytes. The accuracy that was expressed as mean relative error was within ±5.8% while the precision expressed as relative standard error was less than 5.9%. The combination of UA–LDS–DLLME with UPLC–MS/MS is a feasible, sensitive and rapid analytical approach for the determination of ARs in urine matrix, which is particularly suitable for clinical and forensic purposes.