Ultra-high sensitive MSPE-UPLC-MS/MS method based on magnetic nanoparticles for the detection of synthetic cannabinoids in wastewater.

The design and synthesis of Fe3O4@PDA@poly(AA-co-EGDMA) nanoparticles (NPs) as a novel magnetic solid-phase extraction (MSPE) material for efficient enrichment and detection of synthetic cannabinoids (SCs) of various structures in large-volume wastewater is reported. The Fe3O4@PDA@poly(AA-co-EGDMA) NPs were synthesized via a two-step process involving dopamine polymerization and functionalization with poly(acrylic acid-co-ethylene glycol dimethacrylate) polymers, providing hydrophobic and acidic functional groups for enhanced analyte adsorption. An MSPE-ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and optimized for the detection of 24 SCs in wastewater. The method exhibited excellent analytical performance with good linearity (R > 0.99), low limits of quantification (LOQ, 0.02-0.1 ng/L), and good precision with recoveries ranging from 50.20 to 92.72%. The method is capable of reliably analyzing trace SCs in large volume samples (300 mL and 1 L). This study introduces a simple, rapid, and cost-effective MSPE-UPLC-MS/MS approach for detecting SCs in complex environmental samples. The proposed method offers significant potential for wastewater-based epidemiology (WBE) applications, providing a valuable tool for monitoring drug use trends, public health surveillance, and regulatory enforcement.