Determination of Synthetic Musks and UV Filters in Surface Water by Stir Bar Sorption Extraction and Gas Chromatography-Mass Spectrometry

A method for simultaneous determination of 16 synthetic musks (including 5 nitro musks, 6 polycyclic musks and 5 macrocyclic musks) and 2 UV filters (BP-3 and UV-P) in water samples was developed by stir bar sorption extraction (SBSE) with liquid desorption (LD), coupled with gas chromatography-mass spectrometry (GC/MS). In order to get good extraction efficiencies of the target compounds, the important factors affecting the stir bar sorption extraction procedure were discussed, such as extraction time, temperature, stirring speed, volume of sample, pH value, ionic strength, content of organic modifier, different extraction solvents for desorption and the time of liquid desorption by ultrasound extraction. Finally, 50 mL water sample with certain amount of surrogate was stirred extraction for 4 h at 40 ℃ with magnetic stir bar of PDMS, the stirring speed was 950 r/min. Then the stir bar was resolved twice with acetonitrile-acetone solvent. The extract was concentrated to 0.5 mL and added the internal standard for injection. The chromatographic separation was carried on a DB-5MS Ultra Inert column (30 m×0.25 mm×0.25 μm) and detected by mass spectrometry at selected ion monitoring (SIM) mode. The results show that 16 synthetic musks and 2 UV filters have good linearity, the linear range of this method is 2-120 μg/L, while the correlation coefficients (R²) are more than 0.996. The recoveries of three spiked level range from 68.5% to 126%, the relative standard deviations (RSDs) of this method are 2.3%-14.9%, and the limits of detection (LOD) range from 3 μg/L to 0.038 μg/L. Moreover, the method was applied to detect surface water samples in Beijing. The results show that the detection rate of HHCB is the highest, and the concentration is between 0.003 μg/L and 0.337 μg/L. In conclusion, this method is suitable for the rapid analysis of 16 synthetic musks and 2 UV filters in water samples with easy operation, less organic solvent consumption, and can be applied to the accurate analysis of synthetic musks and UV filters in actual surface water samples.