Development of a capillary electrophoresis method for haloacetic acids

An innovative analytical method was developed for directly determining haloacetic acids in drinking water samples without sample derivatization using capillary electrophoresis. All nine haloacetic acids, including monohaloacetic acids, dihaloacetic acids, and trihaloacetic acids, were analyzed. The detection limits for monohaloacetic acids and dihaloacetic acids were less than 3 μg/L, and ranged from 4.0 to 7.0 μg/L for trihaloacetic acids. The spiking recovery for eight haloacetic acids except tribromoacetic acid was in the range of 74.8% to 107%. The newly developed method for haloacetic acid analysis consists of liquid-liquid extraction and capillary electrophoresis with direct UV detection. The extraction and back-extraction took 30 to 45 min to process and the total run time for capillary electrophoresis was 12 min. Further study is needed to improve the peak asymmetry for trihaloacetic acids, method sensitivity, and to simplify or automate the sample extraction process.