Optimization and validation of a multi-residue method for analyzing organic UV absorbers in human urine by UHPLC-MS/MS.

Organic UV absorbers (OUVAs) have gained increasing public concern over the past several years due to their potential adverse effects on humans. The currently available methods for determining OUVAs in humans are typically designed to detect only a limited number of these compounds and lack sufficient sensitivity. In this study, we established a simple and sensitive analytical method that combines liquid-liquid extraction (LLE) with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for the determination of 24 OUVAs and metabolites in human urine samples. This method efficiently analyzes a variety of OUVAs, including benzophenones, benzotriazoles, cinnamates, salicylates, camphor derivatives, triazines, dibenzoylmethane, and aminobenzoic acid derivative. Two extraction approaches, solid-phase extraction (SPE) and LLE, along with various extraction solvents and extraction times were investigated to optimize sample treatment with the aim of achieving high recoveries and minimizing matrix effects. The recoveries of 24 target analytes at three spiked levels (0.02, 0.5 and 2.5 ng/mL) ranged from 70.4 % to 130 %. The lower limits of quantification were 0.004 ng/mL to 0.028 ng/mL for benzophenones, 0.005 ng/mL to 0.012 ng/mL for benzotriazoles, 0.004 ng/mL to 0.026 ng/mL for cinnamates, 0.013 ng/mL to 0.031 ng/mL for salicylates, 0.003 ng/mL to 0.009 ng/mL for camphor derivatives, 0.01 ng/mL to 0.015 ng/mL for triazines, 0.006 ng/mL for dibenzoylmethane, and 0.017 ng/mL for aminobenzoic acid derivative. This is the first study to present a valuable method for the simultaneous determination of multiple urinary OUVAs using a single preprocessing method and dual injection. The analytical method was used for the analysis of OUVAs in 48 urine samples collected from healthy individuals. Eighteen OUVAs were detected, with detection rates ranging from 2.08 % to 100 %, indicating widespread exposure to these compounds among the Chinese population.