determination of Glycolic acid, mono- and di chloroacetic acids in betaine by Amino-functionalized SBA-15 as a effective adsorbent

This paper reports amino-modified ordered mesoporous silica as a new solid phase extractor for determination Glycolic acid, monochloroacetic acid (MCA) and dichloroacetic acid (DCA) in synthetical betaine products. Befor extraction octadecyl silica cartridge was used to reduce the concentration of matrix betaine and a PS-Ag+ pretreatment cartridge was used to remove high Cl− concentration.The amino-modified ordered mesoporous silica (APS-SBA-15) nanoadsorbent exhibited high adsorption affinity for aqueous Glycolate, mono- and dichloroacetate due to the acid and alkaline interactions among the amino functional groups and analytes. Chloroacetates and Glycolate were eluted with 0.8 mol L−1 solution of HClO4 and measured by HPLC with a UV-Vis detector.The effect of pH, flow rate of sample and eluent, type and volume of the eluent were investigated and optimized.At optimum effective parameters, preconcentration factor of 129 was achieved in this method. The detection limits of DCA, MCA and Glycolic acid were 3.7, 13 and 86 ng/L, respectively.

Keywords:

amino-modified mesoporous silica (APS-SBA-15) , Betaine , mono-and dichloroacetic acid , Glycolic acid