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.