A validated UPLC-MS/MS method for the determination of urinary metabolites of Uvinul® A plus

Uvinul® A plus (DHHB) is a synthetic benzophenone derivative mainly used in sunscreens, and also in other skin care products. The compound is authorized by the EU as UV filter and a maximum concentration of 10% in consumer products is permitted. Despite its high production volume and usage in consumer products,to date, no information about the systemic exposure to Uvinul® A plus in humans is available. Therefore, we developed a human biomonitoring method which allows the simultaneous determination of three major metabolites of Uvinul® A plus in human urine samples. Furthermore, three minor metabolites of Uvinul® A plus were identified by ion trap experiments. Urine samples were enzymatically hydrolyzed, extracted via liquid-liquid extraction with ethyl acetate, and analyzed by means of UPLC-MS/MS. The final method was validated according to FDA guidelines and applied to 58 urine samples retrieved from the general German population. The three major and specific metabolites of Uvinul® A plus were found in about 36% of the samples, proving the suitability of the method for future human biomonitoring studies.