Cleaning up blood samples using a modified “QuEChERS” procedure for the determination of drugs of abuse and benzodiazepines by UPLC–MSMS

• Simple blood samples preparation using "QuEChERS".
• Simultaneous determination of drugs of abuse and benzodiazepines and analogues in blood.
• Application on various forensic cases for determination of pharmaceuticals and drugs of abuse.

The “QuEChERS” (quick, easy, cheap, effective, rugged, and safe) dispersive SPE (dSPE) method is an emerging sample preparation technique that is becoming increasingly popular in the area of multi-residue pesticide analysis in food and agricultural products. A simplified QuEChERS extraction method followed by ultra high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) has been developed for the simultaneous determination of forensically relevant drugs of abuse (opiates including buprenorphine, methadone and fentanyl and analogues, cocaine and metabolites, amphetamines, LSD) and benzodiazepines and analogues (Z-drugs) in 1 mL of human whole blood performing a sole extraction. The method was validated showing good repeatability, accuracy and linearity; LODs were 0.5 ng/mL for all benzodiazepines tested while for drugs of abuse LODs varied from 0.05 to 2 ng/mL. The method showed high throughput capabilities and was applied on various forensic cases for determination of pharmaceuticals and drugs of abuse.