Simultaneous enrichment and ultra-high sensitivity detection of multi-structural synthetic cannabinoids in large-volume wastewater.

Nowadays, the abuse of synthetic cannabinoids has aroused the world's great attention. However, the determination of synthetic cannabinoids in wastewater faces the bottleneck of complex species and very low content. Therefore, this work integrated GO-FeO with an ionic liquid (ILs-GO-FeO) to create a mixed hemimicelles magnetic solid-phase extraction (MHMSPE) system for the detection of synthetic cannabinoids (SCs) in wastewater samples using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Because of the multiple interaction sites of mixed hemimicelles' magnetic solid-phase extraction materials, multi-structural synthetic cannabinoids can be enriched simultaneously. Under the optimized conditions, the limits of quantitation (LOQ) of the method were as low as 10-50 pg/L, lower than other methods. The average recoveries of 18 analytes were in the range 71.23-96.08% with relative standard deviations (RSD) lower than 15% (n = 6). To our knowledge, this is the first development of magnetic solid-phase extraction for large-volume samples pretreatment (1 L) and ultra-high sensitive detection of synthetic cannabinoids (10 pg/L), due to the high enrichment factor (10,000-fold). The extraction process was convenient, accurate, and rapid, and offers significant potential for ultra-high sensitivity detection in large-volume samples, providing a valuable tool for simultaneous broad-spectrum extraction and drug abuse monitoring.