HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF PLASMA GLYCOLIC ACID IN HEALTHY-SUBJECTS AND IN CASES OF HYPEROXALURIA SYNDROMES

A liquid chromatographic procedure for the determination of glycolic acid in plasma is proposed. The system is based on pre-column derivatization of the alpha-keto acid by means of phenylhydrazine, coupled with the enzymatic oxidation of glycolate to glyoxylate. The phenylhydrazone formed is separated by reversed-phase liquid chromatography and detected by UV absorption. The measured within and between-batch CV imprecision was 2.6 and 11.3%, respectively, at 5.68-mu-mol/l glycolate concentration; the analytical recovery was 102.0 +/- 7.3% and the minimum detectable concentration of glycolate was 0.3-mu-mol/l. The reference interval for plasma glycolate was 4.51 to 12.20-mu-mol/l (n = 14). Results of determinations of plasma samples from uremic patients, patients with type I primary hyperoxaluria and patients with chronic renal failure secondary to systemic oxalosis are reported.