Determination of Chloracetic Acids in Drinking Water by Ion Chromatography Using Silver Oxide as Precipitant Eliminating Interference of Chlorate in Matrix

In this study, a method was developed for the simultaneous determination of mono-, di-and trichloroacetic acids in drinking water by ion chromatography with large volume direct injection, combined with silver oxide as precipitant to eliminate the interference of chloride ions in matrix and barium hydroxide as precipitant to eliminate the interference of sulfate ions in matrix. This process did not bring in any new interference into sample solution. With a medium high capacity, hydrophobic anion IonPac AS14A column, and sodium hydroxide as eluent, the three chloroacetic acids and chloride and sulfate ions could be well separated and determined in 40 min by gradient elution. A 500-μl sample loop was used. The detection limits for the three chloroacetic acids were 3.7, 3.6 and 35.4 μg l−1. The spiked recoveries for the three chloroacetic acids were between 92% and 106%.