Study of the Aquatic Chlorination of UV Filter Avobenzone in the Presence of Inorganic Salts by Gas Chromatography–High-Resolution Mass Spectrometry

Disinfection is an essential technological stage in water treatment. It is used not only for potable water but also for, e. g., swimming pool water. Water chlorination is the most common method for eliminating microorganisms today. However, active chlorine reacting with natural and anthropogenic compounds dissolved in water gives rise to the formation of numerous compounds that may be hazardous to human health. The assortment of anthropogenic contaminants grows every year; UV filters are well represented among them. Since recently, they are referred to as ecotoxicants, while their application to skin protection becomes more and more popular all over the world. Over 30 compounds, including numerous halogenated derivatives forming in the aquatic chlorination of a popular UV filter avobenzone in the presence of inorganic salts of iron and copper, as well as bromides and iodides, were identified by gas-chromatography–high-resolution mass spectrometry. The study demonstrated the notable variation of the qualitative and quantitative composition of the reaction products depending on the added salt. It is worth mentioning the formation of brominated and iodinated products.