Development of a dispersive pipette extraction method for the determination of eleven sunscreen molecules in seawater samples

[Display omitted] •Dispersive pipette extraction method for sunscreen analysis was developed.•Styrene-divinylbenzene adsorbent was used for extraction.•The extracts were analyzed by HPLC-DAD.•Data obtained revealed the presence of sunscreen in the analyzed seawater samples. Sunscreen molecules are classified as emerging contaminants related to several environmental issues due to the increasing use of cosmetics for sun protection. This study proposes a simple sample preparation approach using the Dispersive Pipette Extraction (DPX) technique, followed by identification and quantification by high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD), to determine eleven sunscreen molecules in seawater samples. The DPX parameters, including extraction phase, sample volume, desorption solvent, extraction time, desorption time, and number of cycles, were optimized using univariate and multivariate designs. Styrene-divinylbenzene was selected as the extraction phase in the DPX procedure. The extraction process consisted of three 25-second cycles in 2400 μL of the sample divided into three vials, i.e., aliquots of 800 μL each. In the desorption step, three 10-second cycles were performed with a single 200 μL aliquot of acetonitrile. The analytical performance of the method was evaluated, showing coefficients of determination equal to or greater than 0.9958, precision with coefficients of variation below 10 %, recoveries ranging from 80 % to 116 %, and matrix effect values were negligible and could be ignored. The method was applied to determine the sunscreen molecules in eight seawater samples from different collection points, and all the samples showed at least one of the eleven analytes being studied. These data confirm the widespread presence of sunscreen molecules in the marine environment. The optimized DPX-based sample preparation method and the validated chromatographic method proved to be effective for the determination and quantification of these contaminants in the marine environment.