Simultaneous Determination of Amitraz and its Metabolites in Blood by Support Liquid Extraction Using UPHLC-QTOF

This paper describes the use of UPHLC-QTOF for the analysis of pesticide amitraz and its metabolites in human blood. UPHLC-QTOF working in full scan mode simultaneously with a single MS/MS scan at 10 eV was employed to analyze in solid-support liquid-liquid extracts (SLE) of the human blood. Detection and quantification were carried out using full scan data (protonated molecules [M+H]+) while MS/MS data were used for fragment identification only. MS/MS scans were not found to have any negative influence on quantitation under the applied conditions. Verification studies were accomplished at low concentrations (1 ng/mL), and accuracy errors lower than 5 ppm were achieved. The human blood extracts spiked at LOQ and three QC fortification levels produced average recoveries in the range of 79.3-92.5% with relative standard deviations smaller than 10% for all analytes. Limits of detection (LODs) were between 0.1 and 0.5 ng/mL. Finally, the proposed method was successfully applied to a case of human poisoning.