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. Copyright © 2016 John Wiley & Sons, Ltd.

Information about stability of synthetic cannabinoids is important to give recommendations for storage conditions in cases in which use of synthetic cannabinoids is suspected. In this study, freeze-thaw stability (3 cycles at -20 °C at 1.5 ng/mL) and long-term stability at room temperature, 4°C and -20°C (for 150 days) were tested by a validated liquid chromatographic-mass spectrometric method for 80 synthetic cannabinoids. Results demonstrated good freeze-thaw stability for most of the substances. For 5 F-ABICA (72.6% of peak area of time point zero), 5 F- 2 ADB PINACA 2 Isomer (68.7 %), 5Cl-AB-PINACA (84.2 %), AB FUBINACA 2-Isomer (33.5 %), 5 F-PCN (89.7 %), ADB-FUBINACA (78.0 %), EG 018 (88.9 %), and PX-1 (89.4 %) three freeze-thaw cycles led to absolute peak areas < 90% compared to 6 control samples. For 51 of the 84 substances, stability in serum could be demonstrated after 315 days of storage at -20°C. For 82 of the 84 substances, stability in serum could be shown for at least 1 month at -20°C. Long- term stability at 4°C or 20°C showed worse results. Therefore, it is our recommendation to store real serum samples at -20°C until analysis. Copyright © 2016 John Wiley & Sons, Ltd.