A novel approach for determination of paraquat based on dried blood spot (DBS) extraction and UHPLC-HRMS analysis

摘要

Paraquat is an effective herbicide chemical but a highly toxic compound for humans and animals. The measurement of paraquat concentration in blood is important to clinic or forensic practice. Herein, a method has been developed for the analysis of paraquat in human blood using dried blood spot (DBS) extraction and subsequent UHPLC-HRMS analysis. Three droplets (100 μL each) of blood were spotted on the Whatman?FTA classic card and then let dry by microwave irradiation (1200?W) for 5?min to prepare DBS. An 8?mm diameter punch was removed from the center of DBS and extracted with 190 μL of mobile phase (20?mM ammonium acetate with 0.1% formic acid and 5% acetonitrile in ultra-pure water) and 10 μL of internal standard (paraquat-d8, 100?ng/mL). After ultrasonic treatment for 10?min, the tube was centrifuged, and the supernatant was then filtered by 0.2 μm membrane and injected into the UHPLC-HRMS system. The method was validated considering the following parameters: selectivity, LOD and LLOQ, linearity, precision, accuracy. The method showed satisfactory linearity in the range of 1–1000?ng/mL, with high determination coefficient (0.9986). LOD was 0.5?ng/mL, and LLOQ was 1?ng/mL. Selectivity, intra and inter day precision and accuracy were acceptable. The validated method was then applied to authentic blood samples and has proved to be a simple, fast and reliable procedure for the determination of paraquat in blood.