The formation of di- and trichloroacetic acid (TCAA and DCAA) during beverage preparation and its impact on quantitative exposure assessment for drinking water disinfection by-products

The effect of beverage preparation on trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) concentrations was assessed by analysis of water samples and samples of beverages made with the same water. Samples were analyzed by solid phase microextraction with gas chromatography using electron capture detection (SPME GC-ECD). TCAA and DCAA concentrations increased when beverages were prepared. Increasing the chlorine residual caused a corresponding increase in the concentration of TCAA and DCAA when beverages were prepared. Increase in TCAA from coffee preparation was applied to hot beverage ingestion data from a human exposure trial. Applying the elevated exposure estimates showed a considerable impact on estimated TCAA ingestion and excretion, especially for those ingesting large volumes of hot beverages. TCAA ingestion exposure estimates are affected by applying beverage data, indicating that a reliable exposure estimate should include beverage ingestion information.