Identification and Quantification of Toxic Unsaturated C4-Dicarbonyl Ring Cleavage Products from the Chlorination of Varying Phenolic Compounds

Nicholas Pham

Mentor: Dr. Carsten Prasse

The Prasse Lab, Johns Hopkins Bloomberg School of Public Health

Around the world, chlorination is the most widely used method of water disinfection due to its low cost and effectiveness. However, despite its effectiveness in removing pathogens, the addition of chlorine to water containing organic and inorganic constituents can also result in the formation of toxic disinfection byproducts (DBPs). A novel and toxic DBP species from chlorination that has drawn more attention recently is cis-2-butene-1,4-dial (BDA). This study focuses on the yields of BDA from different phenolic precursor compounds. Bench scale chlorination experiments were conducted on methylparaben, 4-hydroxybenzophenone, and 2-naphthol, simulating conditions similar to those observed in drinking water treatment plants (at a neutral pH of 7.5). N-α-acetyl-lysine (NAL) was added to samples after chlorination for derivatization of BDA. Samples were analyzed by an ultra high-performance liquid chromatography-high resolution mass spectrometer (uHPLC-HRMS) in order to detect transformation products from the chlorination reaction. It was found that all the selected model phenolic compounds produced BDA or its analogues, revealed from the detection of lysine adducts, the products from derivatization.