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.
|Number of pages||8|
|Journal||Archives of Environmental Contamination and Toxicology|
|Publication status||Published - May 2009|
Scopus Subject Areas
- Health, Toxicology and Mutagenesis