Multi-residue screening method of 195 drugs of abuse and metabolites in whole blood using LC-MS/MS and application to real blood samples.

Polydrug use is a growing concern in the forensic field due to its high risk of overdose and its significant impact on physical and psychological health. Hence, the development of methods for simultaneously analyzing multiple drugs in blood has become increasingly essential recently. The aim of this study is to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous detection of 195 drugs of abuse (DOAs), including amphetamines, opiates, cathinones, phencyclidines, synthetic cannabinoids, cocaine, and metabolites, in 100 μL of blood. Blood samples were extracted using liquid-liquid extraction (LLE) with acetonitrile containing 0.1 % trifluoroacetic acid, and multiple reaction monitoring (MRM) was employed for the detection of 195 drugs and metabolites in a single run. The method was validated over a concentration range of 1-100 ng/mL for all target compounds, showing good linearity with a coefficient of determination (R²) greater than 0.99 for 193 compounds. The limits of quantification (LOQs) of target analytes ranged 0.1-10 ng/mL. The method was successfully applied to 20 real blood samples, detecting 22 drugs of abuse and their metabolites, with concentrations ranging from 0.2 to 401.4 ng/mL. This developed method is expected to be highly applicable in the forensic or clinical field for the rapid detection of polydrug use.