Optimized and Validated DBS/MAE/LC–MS Method for Rapid Determination of Date-Rape Drugs and Cocaine in Human Blood Samples—A New Tool in Forensic Analysis

Abstract

The aim of this work was to develop a new method for the determination of selected substances from the date-rape drugs group: ketamine, benzodiazepines and cocaine. The method is based on the dried blood spot method which seems to be a suitable tool in the analysis of tested substances. The extraction process based on microwave-assisted extraction was optimized to enable optimal conditions for the isolation of a wide range of analytes from blood samples collected on DBS cards. The extraction with ethyl acetate with a buffer of pH = 9 carried out at a temperature of 50 °C for 15 min ensured high extraction efficiency of the tested analytes. The optimized method was validated. Limits of detection (LOD = 4.38–21.1 ng/mL) and quantification (LOQ = 14.6–70.4 ng/mL), inter- and intra-day precision (CV = 1.37–13.4% and 3.39–14.8%, respectively), recovery (RE = 93.0–112.4%) and matrix effect (ME = 98.4–101.6%) were determined. The validation results indicate the possibility of using the proposed method in the analysis of real blood samples collected from victims of sexual assault.