Determination of Dichloroacetic acid and Trichloroacetic acid of disinfection by-products in drinking water by free reagent ion chromatography

Objective To develop a method for simultaneous determination of dichloroacetic acid and trichloroacetic acid of disinfection by-products in drinking water by free reagent ion chromatography.Methods The target analytes in drinking water sample were separated on Ionpac AS19 anion exchange column with 8 mmol / L ～ 45 mmol / L KOH generated on line for gradient elution,and detected by conductivity detector with the injection volume of 500μl,the flow rate was 0.8 ml/min.Results This method had good linearity in the range of 0 mg/L ～0.20 mg/L and good analytic precision( RSD % 4.0).The correlation coefficient was 0.9991 for dichloroacetic acid and0.9995 for trichloroacetic acid.The recovery rate was 90.5% ～ 99.4% for dichloroacetic acid and 86.5% ～97.0% for trichloroacetic acid.The detection limit was 1.22 μg / L for dichloroacetic acid and 1.90 μg / L for trichloroacetic acid.Conclusion This method is simple,rapid and sensitive.It is available to determine the dichloroacetic acid and trichloroacetic acid of disinfection by-products in drinking water by free reagent ion chromatography.