Simultaneous Determination of Chloroacetic Acid, Dichloroacetic Acid, Acetic Acid in Industrial Chloroacetic Acid by High Performance Liquid Chromatography

The sample of industrial chloroacetic acid was dissolved with mobile phase composed of 0.05% phosphoric acid solution and methanol in volume ratio of 95:5, the mixture was filtered by 0.45 μm filter membrane, and the contents of chloroacetic acid, dichloroacetic acid and acetic acid in filtrate were determined by high performance liquid chromatography (HPLC). The Inert Sustain AQ-C₁₈ chromatographic column was chosen as stationary phase, the mobile phase was used for isocratic elution, and the detection wavelength of 215 nm was adopted for determination. The results showed that the 3 target compounds were all got baseline separation. Linearity relationships between mass concentration of chloroacetic acid, dichloroacetic acid, acetic acid and their respective peak areas were all kept in defite ranges, with correlation coefficient greater than 0.999 5, and detection limits (3S/N) of chloroaectic acid, dichloroacetic acid and acetic acid were 0.19, 0.08, 0.12 mg·L^-1, respectively. The 6 parallel tests were made on actual samples by the above method, giving values of RSDs of 0.11%, 6.6%, 5.1% and ranges of 0.32%, 0.03%, 0.03%, meeting requirments of difference of determined values specified by standard of HG/T 3271-2000. Recoveries found by the spiked recovery on the actual sample were kept in the ranges of 99.8%-100%, 97.5%-101%, 96.7%-102%, respectively. Compared with standard method HG/T 3271-2000, the range of the determined values given by the proposed method was smaller.