Fast pressurized liquid extraction with in-cell purification and analysis by liquid chromatography tandem mass spectrometry for the determination of UV filters and their degradation products in sediments

This paper presents the development of a fast and sensitive analytical method for the simultaneous determination of UV filters and degradation products having quite different polarities (log Kow 2.19-6.88) in sediment, by means of pressurized liquid extraction (PLE) with in-cell purification and analysis by ultra-performance liquid chromatography (UPLC) coupled to tandem mass spectrometry (MS/MS). Analytes were simultaneously concentrated and purified by placing aluminium oxide as clean-up sorbent in the extraction cell for a faster sample pre-treatment. Under optimized conditions, quantitative recoveries (only one compound below 80%) and satisfactory precision (RSD, 5-15%) were obtained. Low limits of detection were achieved of 0.5-15 ng/g dry weight (dw). The use of PLE extraction and purification and UPLC technology enabled all the compounds to be separated chromatographically in less than 9 min, and with a total chromatographic analysis time of 18 min. This method significantly decreased the overall time of analysis as compared to those of previously developed. Finally, the optimized methodology was applied to investigate the occurrence of the target UV filters in sediment samples collected along the Ebro river basin (Spain). UV filters were detected in 95% of the sediment samples analysed. Results revealed a widespread presence of octocrylene (OC), reaching concentrations up to 24 x 10(2) ng/g dw, the highest reported so far. Ethylhexyl dimethyl PABA (OD-PABA) and benzophenone-3 (BP3) were also frequently detected (60-65%), but at lower concentrations (4.4-27 ng/g dw). 4DHB (an estrogenic degradation product of BP3) was present in three samples at concentrations between 12 and 21 ng/g dw. These results constitute the first data on the occurrence of OD-PABA and 4DHB in sediments.