Determination of d-2-hydroxyglutaric acid in urine samples using enantioselective, potentiometric membrane electrodes based on antibiotics

Enantioselective, potentiometric membrane electrodes (EPMEs) based on carbon paste are constructed. The carbon paste is modified with antibiotics: vancomycin, teicoplanin, and teicoplanin modified with acetonitrile. The proposed electrodes can be used reliably for enantiopurity tests of d-2-hydroxyglutaric acid using direct potentiometric method of analysis. The linear concentration ranges recorded for EPMEs are 10−7 to 10−3, 10−7 to 10−2 and 10−6 to 10−2 mol/L with detection limits of 1.00 × 10−8, 1.00 × 10−8, 1.00 × 10−7 mol/L for the vancomycin, teicoplanin and teicoplanin modified with acetonitrile based EPME, respectively. The selectivity was determined over l-2-hydroxyglutaric acid, creatine, creatinine and some inorganic cations. The proposed EPMEs were applied for the assay of d-2-hydroxyglutaric acid in urine samples. The duration of one analysis is 10 min, including the calibration of the instrument and the determination of the amount of d-2-hydroxyglutaric acid in the urine sample.