Rapid Screening of 18 Synthetic Cannabinoids Using Atmospheric Pressure Solids Analysis Probe Coupled With Single-Quadrupole Mass Spectrometer

Synthetic cannabinoids (SCs) have extremely strong biological activity, and have become new psychoactive substances (NPS) with the most types and the most diverse abuse. SCs induce severe adverse effects, including tachycardia, respiratory difficulties, hypertension, acute renal failure, suicidal ideation, psychosis and cognitive impairment. Chronic use of SCs has been associated with serious psychiatric and even death. There are various types of SCs seized by the anti-drug department of public security in various cases, and their compositions are unknown. Therefore, there is an urgent need for rapid qualitative detection techniques for SCs in unknown samples. In this study, a method of utilizes atmospheric pressure solids analysis probe coupled with single-quadrupole mass spectrometer (ASAP-MS) was determined to rapidly screen 18 SCs. It can be used for the analysis of solid or liquid samples with very simple pretreatment and no need for chromatographic separation. The method consistd of four steps: dissolving the sample, centrifuging and separating the liquid, inserting the capillary probe for collection, and getting the real-time matching results. Combined with Live ID software, it could automatically search for a home-built mass spectral library and rapidly identify suspicious additives. Firstly, the cone hole voltage of ASAP-MS analysis was optimized, four cone hole voltages of 15, 25, 35 and 50 V could provide comprehensive mass spectral information of the compounds. Secondly, a series of SCs standard solutions were analyzed under optimized conditions, and the mass spectral libraries of the 18 SCs were established. Thirdly, using Live ID software, the ASAP-MS analysis data were automatically matched online in the home-built library, and the suspicious compounds were scored in the range of 0-999 points. The whole analysis process could be completed within 2 min. Fourthly, the proposed method was subsequently validated using different concentrations of standard solution (10-100 mg/L, methanol) based on the optimized condition and SC-positive standard samples. The detection limits of the 18 SCs are 10-20 mg/L, and the results showed a total score of 991 for the 100 mg/L ADB-BUTINACA match (three replicates). Finally, the prosed ASAP-MS method was applied to analyze 15 batches of unknown samples sized, and 9 batches were shown positive result. This method has the advantages of simple preprocessing, fast analysis, efficient and accurate matching, and accurate qualitative analysis. If the detection limit is lower than that of LC-MS/MS, then qualitative detection can only be conducted. Nevertheless, this method is sufficient for the detection of suspected SCs, and it can be widely applied to grassroots public security anti-drug departments, which may lack professional laboratory conditions and experienced staffs.