Preparation of polydopamine-functionalized mesoporous silica-coated core/shell magnetic nanocomposite for efficiently extracting five amphetamine-type stimulants from wastewater followed by UPLC-MS/MS determination

Wastewater-based epidemiology (WBE) was a near-real-time monitoring strategy for illegal drugs. However, solid-phase extraction (SPE) widely used in WBE was time-consuming and labor-intensive to extract ultra-trace target compounds from wastewater. In this study, a convenient magnetic solid-phase extraction (MSPE) approach based on newly designed and synthesized polydopamine functionalized core-shell magnetic mesoporous silica (Fe 3 O 4 @nSiO 2 @mSiO 2 @PDA) nanocomposite was synthesized and firstly utilized for simultaneously extracting five amphetamine-type stimulants (ATSs) from wastewater samples. Subsequently, ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method coupled with optimal MSPE was developed for determination of ultra-trace ATSs in wastewater. The validation results indicated a favorable linearity ranging from 1 to 200 ng L −1 , low limit of detection (0.5–2.5 ng L −1 ), and qualified recovery (95.1–106.6%) and repeatability (0.6–6.2%). In addition, the Fe 3 O 4 @nSiO 2 @mSiO 2 @PDA nanoparticles could be reused for at least ten times without significant loss of the adsorption efficiencies of ATSs. Finally, the MSPE-UPLC-MS/MS method was successfully applied to real wastewater samples with the results that the preparation procedure was shrunk from 2 h to 30 min without obvious decline of extraction efficiency compared with the SPE. Hence, based on merits of the novel Fe 3 O 4 @nSiO 2 @mSiO 2 @PDA nanocomposite, the proposed method is convenient and reliable for determination of ATSs in wastewater.