Determination of seven precursor substances of 1-phenyl-2-propanone in atmospheric particulate matter by LC-MS/MS: A novel strategy for monitoring illicit drug synthesis and assessing potential health risks

In the process of illicit drug production and manufacture, some of the precursors might escape into the air and adhere to the surface of airborne particulate matter. The detection of precursor substances in atmospheric particulate matter in the vicinity of suspected drug manufacturing facilities can assist in the deduction of drug synthesis pathways and the reduction of illicit drug preparation at the source. In recent years, there has been a notable transition in methamphetamine synthesis from the ephedrine/pseudoephedrine-based route to the 1-phenyl-2-propanone (P2P)-based route, underscoring the growing significance of P2P and its precursor chemicals in the surveillance and control of illicit drug manufacturing. In this study, airborne particulate matter was enriched using an atmospheric particulate matter sampler, and the samples were processed by wet milling method. A quantitative method for the detection of seven precursor substances of P2P was established by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that the limits of detection for the seven precursor substances of P2P were in the range of 0.20–0.50 ng/mL, and the linear correlation coefficients (r) were all greater than 0.9940. The matrix effects and recovery at three spiked levels were in the ranges of 92.1 %–107.4 % and 94.0 %–105.2 %, respectively. Utilising this method to collect the actual samples from the laboratory, 3-oxo-2-phenylbutanamide (APAA) was detected in the in vitro sample weighing room and was identified at a concentration of 91.5 pg/m³ on the initial day of collection. It was determined that the maximum possible daily inhalation dose of APAA for room occupants was 1.83 × 10⁻⁶ mg. Subsequently, a nonlinear function correlating concentration and collection date was fitted, laying the research foundation for combating the illicit preparation of methamphetamine synthesised via P2P and highlighting the occupational exposure of anti-drug personnel and health threat to nearby residents due to high-concentration, drug-related atmospheric particulate matter.