Abstract:

A method for determination of glycolic acid, monochloroacetic acid and dichloroacetic acid in alkylpolyethoxy carboxylate （AEC） by high performance liquid chromatography was established. The column was Acclaim Trinity P1 column （3.0 mm×150 mm, 3 μm） for separation and it was adapted gradient with 10% acetonitrile-90% phosphate buffered saline （10 mmol sodium dihydrogen phosphate, adjust pH to 5.0）. A UV detector at 210 nm was used. The separation and determination of glycolic acid, monochloroacetic acid and dichloroacetic acid could be completed. The resolution of chromatographic peaks of the three compounds to be tested in the sample solution is good, and the peak area and concentration of the reference substance show good linear correlation, and the correlation coefficients are greater than 0.999. The stability and precision of the analysis meet the requirements of methodological investigation. The average recovery of three compounds is in the range from 96% to 98%, and the relative standard deviation （RSD） is less than 3%. Compared with the method of GB/T 28193—2011 （Determination of chloroacetic acid （chloroacetate） contents in surfactants）, this method is not limited by product solubility, and can be used in product systems with long carbon chain or poor water solubility. Therefore, it has a wider scope of application, and it can provide references for AEC product quality control, production process upgrading and test method improvement.

Key words: alkylpolyethoxy carboxylate, glycolic acid, monochloroacetic acid, dichloroacetic acid, high performance liquid chromatography