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 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-C, LC-C 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) with the correlation coefficient R > 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. 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.