Simultaneous detection of 93 synthetic cannabinoids by liquid chromatography-tandem mass spectrometry and retrospective application to real forensic samples.

The Internet is flooded with steadily changing synthetic cannabinoids in `Spice` products. In routine forensic work, it is difficult to keep the analytical methods for the detection of these analytes up to date. We describe a liquid chromatography-tandem mass spectrometry method after liquid-liquid extraction for the detection of 93 synthetic cannabinoids in human serum. The method was validated for selectivity and specificity, matrix effects, and analytical limits (<1 ng/mL for 81 substances) for qualitative analysis. A short quantitative validation regarding linearity and precision data was also conducted. The method was applied to 189 serum samples provided by police authorities. Sixty-four samples (33.8%) were found positive for at least one synthetic cannabinoid, whereby MDMB-CHMICA, AB-CHMINACA, and 5 F-PB-22 were the substances most frequently detected. Consumption of these substances and plasma concentrations are linked to symptoms documented by the police. Six case reports are presented.