Ionic liquids-based nanoemulsion for assisted by ultrasound liquid–liquid microextraction of UV-filters in water samples

Abstract

Organic UV filters can contaminate various bodies of water such as streams, rivers, and seas, and as such, they have been identified as emerging contaminants of relevance in aquatic ecosystems. Therefore, the detection and determination of these compounds at low concentrations from an environmentally friendly perspective are necessary. In this work, an ionic liquids based nanoemulsion for the ultrasound assisted liquid–liquid microextraction (ILs-NE/US-LLME) of benzophenone-3, octocrylene, octisalate and octinoxate in different water bodies was reached. The material was based on a mixture of the ionic liquids 1,3-didecyl-2-methylimidazolium chloride and 1-butyl-3-methylimidazolium hexafluorophosphate, and the surfactant Triton X-100. The microextraction process was assisted by ultrasound and was performed using 475 µL of extractant solvent and 10.0 mL of sample, and an optimal preconcentration factor of 100 was achieved. The detection was performed by HPLC-UV in less than 5 min for all analytes. Low detection limits (lower than 2.0 µg L− 1 ) and an optimal precision (RSD lower than 6.7 %) were obtained for the four UV filters. Different water samples (pool, stream, river, sea and a simulated sample) were analyzed and satisfactory recovery values were obtained in all cases (82–119 %). The method was fast (15 min− 1 ) and it presented an optimal value of greenness (0.50) according to the AGREE metric. The extractant material was easily synthesized using a minimum amount of materials. The chromatographic procedure for separation and detection of the analytes was simple and fast. Moreover, the method was more environmentally friendly compared to previous work reported in the literatur