Thin-film microextraction using the metal-organic framework DUT-52 for determining endocrine disrupting chemicals in cosmetics
Adrián Gutiérrez‐Serpa, Jorge Pasán, Ana I. Jiménez‐Abizanda, Stefan Kaskel, Irena Senkovska, Verónica Pino
Abstract
Metal-organic frameworks (MOFs)-based mixed-matrix membranes (MMMs) were used in a thin-film microextraction (TFME) method for the determination of six personal care products (PCPs) present in cosmetic samples, using ultra-high performance liquid chromatography coupled to a UV/Vis detector (UHPLC-UV/Vis). The type of MOF used (testing UiO-66, UiO-66-COOH, UiO-67, DUT-52, DUT-67, MOF-801, and MOF-808) in the MMM as well as the amount of MOF loaded (up to 60%, w/w) were optimized carefully to select the most adequate MOF-based MMMs for the analytical application. The type of exposure of the MOF-based MMM to the sample, the agitation mode, and the dimensions of the membranes, were also carefully evaluated. Besides, the main parameters affecting the TFME procedure were optimized by a Doehlert experimental design, dictating the following optimum conditions: the MOF DUT-52 MMMs presenting a 60% (w/w) of MOF loading, with membranes prepared using a 250 µm thickness as gap height (resulting in thicknesses of ∼ 60 µm once all solvents of the membranes are removed) and dimensions of 2 × 2 cm, 90 min of TFME time, a vortex assisted desorption step using 625 µL of acetonitrile (2 × times), and a further preconcentration to 150 µL. The entire method showed adequate analytical performance with limits of detection down to 0.030 ng·mL−1, and intra-day, inter-day, and inter-batch precision values (as RSD), better than 10%, 14%, and 20%, respectively, for a concentration level of 75 ng·mL−1. Three cosmetic samples were analyzed, with proper calibrations in the matrix, thus proving the stability and applicability with these matrices. Besides, a thorough study of the greenness of the method was assessed by application of the different existing metrics.