离子色谱法测定椰油酰胺丙基甜菜碱中一氯乙酸和二氯乙酸

Determination of monochloroacetic acid and dichloroacetic acid in cocamidopropyl betaines by ion chromatography

建立了离子色谱法测定椰油酰胺丙基甜菜碱中微量一氯乙酸（MCA）和二氯乙酸（DCA）的方法。采用3．2mmol／L碳酸钠和1．0mmol／L碳酸氢钠混合溶液作流动相，MCA和DCA检出限分别为0．011mg／L和0．032mg／L，线性相关系数分别为1．0000和0．9998，加标回收率分别为93．1％～101．8％和92．6％-99．1％，能满足工业分析要求。

An ion chromatography method for measuring residual monochloroacetic acid （MCA） and dichloro- acetic acid （DCA） in cocamidopropyl betaines was developed. This method uses a mixed solution composed of 3.2 mmol/L sodium carbonate and 1.0 mmol/L sodium bicarbonate as mobile phase. The dectection limit （LOD） of MCA and DCA was identified as 0. 011 mg/L and 0. 032 mg/L respectively. The linear correlation coefficient was 1. 000 0 and 0.999 8 respectively. The recovery of adding standard sample for MCA and DCA was 93.1% - 101.8% and 92.6% -99.1% respectively. It showed that this method meets the requirements of technical analysis.