Determination of UV Filters in Surface Water by VA‐DLLME‐SFOD Technique Coupled with GC‐MS/MS

A simple, rapid, and sensitive method is developed for the determination of UV filters in river waters by applying the vortex‐assisted dispersive liquid–liquid microextraction based on solidified floating organic droplet technique followed by the injector port silylation (IPS) in a gas chromatography‐tandem mass spectrometry system. Statistical experimental design methods including general factorial design, one factor at a time, and central composite face‐centered design are used for optimization purposes. Under optimized conditions, 460 µL of acetone and 30 µL of 2‐dodecanone are rapidly injected into a 10 mL water sample with 10% (w/v) NaCl at pH 2.5 and vortexed for 3 min. After centrifugation, 2 µL of the separated organic solvent is subjected to auto‐IPS with 1 µL of bis (trimethylsilyl) trifluoroacetamide containing 1% trimethylchlorosilane, at 260 °C for 4.5 min in programmable temperature vaporization mode. As a result of the validation studies, the intra‐day and inter‐day precision indicated as relative standard deviation are less than 12.4% and 18.8%, respectively. For all UV filters, detection limits are between 1.1 and 5.5 ng L−1 and limit of quantitation values are between 3.1 and 16.6 ng L−1. Successful recovery of extraction values (77.1%–107.4%) and good enrichment factors (231–350) are obtained. A novel dispersive liquid–liquid microextraction‐solidified floating organic droplet method is developed for the preconcentration of emerging UV filters by a gas chromatography‐tandem mass spectrometry system. The analytes enriched in a nonchlorinated solvent drop is subjected to silylation in the injector port prior to quantitation. Analytical method performance is statistically optimized by central composite face‐centered design and the method is validated by using environmental water samples.