Simultaneous Determination of Seven Benzotriazole UV Stabilizers in Surface Waters by Using Solid-Phase Extraction Coupled With Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry With Electrospray Ionization

Benzotriazole ultraviolet stabilizers (BUVSs) are emerging persistent pollutants, due to the weak polarity and wide log K_ow values, there is no general optimal analytical method for BUVSs. In this study, a solid-phase extraction-ultra performance liquid chromatography tandem mass spectrometry (SPE-UHPLC/MS/MS) method was developed for the simultaneous determination of seven BUVSs in the aqueous environment, based on the generalized electrospray ionization (ESI+) mode. The conditions of ESI-UHPLC-MS/MS detection and SPE were systematically optimized. A 50 mm UHPLC column at a column temperature of 40°C gave the highest response for the target BUVSs using methanol–0.1% (v/v) formic acid solution as the mobile phase. The effects of the four packed SPE cartridges (HLB, HC-C₁₈, LC-C₁₈ and phenyl columns) and sample pH (3.0–9.0) on the SPE enrichment were comparatively analyzed, and the optimum condition was HLB cartridges at sample pH 3.0. The SPE elution solvent was optimized as 5 mL methanol + 5 mL dichloromethane (V:V = 1:1). The seven target BUVSs were quantified by isotope internal standard method, and the linear range of the standard curve was wide (0.1–50 ng∙L⁻¹) with the correlation coefficient R² > 0.998. The recoveries of the spiked standards for the purified water as well as the sample of Huangpu River were 80.6%–105.2% and 53.9%–103.7% (except UV-P: 141.6%–148.7%), respectively. The relative standard deviations (RSDs) of the intra-day were 4.1%–18.0%; and the RSDs of the inter-day were 3.4%–18.8%, respectively. The limits of detection of the method were in the range of 0.050–0.406 ng∙L⁻¹. Compared with the reported studies, this method is more sensitive and stable, and the UHPLC-MS/MS instrument based on the ESI ionization source is more generalizable.