Simultaneous determination of seven anaesthetic-related compounds in municipal sewer wastewater using solid-phase extraction followed by HPLC-MS/MS: method development and occurrence analysis

Solid-phase extraction (SPE) coupled to HPLC-MS/MS was used to measure seven anaesthetic-related compounds in municipal sewer wastewater.. During sample pretreatment, three SPE sorbents were evaluated, and mixed-mode cation exchange (MCX) provided the best overall performance. Chromatographic separation was achieved on a Phenyl column, and detection was performed by positive electrospray ionization mode. Under the optimized conditions, all analytes showed good linearity (R2 >0.999), with limits of detection and quantification of 0.172–1.74 ng L−1 and 0.573–5.82 ng/L, respectively. Mean recoveries at three spiking levels ranged from 86.7% to 116.4%, with RSDs below 15%. Matrix effects ranged from 80.5% to 96.7%, indicating limited ion suppression after sample cleanup. The method was applied to 24 real samples, and the detection frequencies of the seven analytes ranged from 17% to 100%, with summed concentrations of 24.3-1.05 × 103 ng/L. The method is suitable for the routine monitoring of anaesthetic-related contaminants in wastewater.