Determination of Glycolate Acid, Mono- and Dichloroacetic Acids in Synthetical Betaine by Anion-exchange Chromatography

• Published in: Chinese journal of chemistry 2011-04, Vol.29 (4), p.778-782
• Main Author: 石海宁 王宗花 王辉 赵锐 丁明玉
• Format: Article
• Language: English
• Subjects: dichloroacetic acid; glycolate acid; ion chromatography (IC); monochloroacetic acid; NaHCO3; solid phase extraction (SPE); synthetical betaine; 乙醇酸; 二氯乙酸; 甜菜碱; 阴离子交换柱; 阴离子交换色谱法; 高氯离子浓度
• ISSN: 1001-604X; 1614-7065
• DOI: 10.1002/cjoc.201190157

An anion-exchange chromatography method combined solid phase extraction （SPE） was developed for the simultaneous analysis of glycolate acid （GL）, monochloroacetic acid （MCA） and dichloroacetic acid （DCA） in synthetical betaine products. The analytes and unknown anionic impurities were well separated on a Metrosep A supp5 anion-exchange column （150 mm×4 mm） with 2.0 mmol/L Na2CO3＋2.0 mmol/L NaHCO3 solution as eluent. Suppressed conductivity detection was used. A strong cation exchange （SCX） solid phase extraction （SPE） cartridge was used to reduce the concentration of matrix betaine and a Cleanert IC-Ag pretreatment cartridge was used to remove high Cl- concentration. The detection limits of GL, MCA and DCA were 0.09, 0.017 and 0.05 μg/L, respectively. The relative standard deviations （RSDs） of the retention times and peak areas were less than 0.09% and 0.49%, respectively. The recoveries of the three analytes were between 90.6% and 100.8%. The analytical results showed that GL and DCA were present in high concentration and no MCA was found when the proposed ion chromatography method was applied to three synthetical betaine samples. The proposed method is simple, sensitive and timesaving, and is also suitable for routine analysis in quality control of synthetical betaine products.