Enantioanalysis of l-2-hydroxyglutaric acid in urine samples using enantioselective, potentiometric membrane electrodes based on maltodextrins

Abstract

Quantitative assay of l-2-hydroxyglutaric acid ( l-2-HGA) is important for the diagnosis of l-2-hydroxyglutaric aciduria. Three enantioselective, potentiometric membrane electrodes (EPMEs) based on maltodextrins with different dextrose equivalent (DE) (DE: 4.0–7.0 (I), 13.0–17.0 (II), 16.5–19.5 (III)), were designed for the enantioanalysis of l-2-HGA. The enantioselective, potentiometric membrane electrodes can be used reliably for enantiopurity assay of l-2-HGA using the direct potentiometric method in the ranges of 10 −9–10 −5, 10 −6–10 −3 and 10 −8–10 −5 mol L −1 for the enantioselective, potentiometric membrane electrodes based on maltodextrins I, II and III, respectively, with very low detection limits. A high reliability was obtained when the electrodes were used for the assay of l-2-HGA in urine samples.