Twenty amino acids were chlorinated and examined for the formation of trihalomethane (THM) and haloacetic acid (HAA). The amino acids exhibited a high Cl₂ demand (3.4–10 mg Cl₂ mg⁻¹ C) but low THM formation (<4.19 μg mg⁻¹ C) except for tryptophan and tyrosine (45.8 − 147 μg mg⁻¹ C). Large variation in HAA yield occurred among the amino acids (from not detectable to 106 μg mg⁻¹ C). One group of amino acids, possessing chain structures, exhibited a slow increase in HAA formation (<6.2 μmol mol⁻¹ amino acid or <11.3 μg mg⁻¹ C) as the chlorine demand increased (3.4–8.9 mol Cl₂ mol⁻¹ amino acids). The other group of amino acids, containing ring structures (including tryptophan, tyrosine, histidine, phenylalanine, and proline) and two amino acids with chain structures (aspartic acid and asparagine), showed a fast increase in HAA formation (16–96 μmol mol⁻¹ amino acid or 27–106 μg mg⁻¹ C) with the increase in chlorine demand (5.2–15.9 mol Cl₂ mol⁻¹ amino acid). The ratios of TCAA to DCAA (mol/mol), derived from the amino acids, ranged between 0.01 and 1.10. Copyright © 2008 Springer Science+Business Media, LLC.
|Journal||Archives of Environmental Contamination and Toxicology|
|Publication status||Published - May 2009|