High-performance liquid chromatographic assay for L-glyceric acid in body fluids. Application in primary...

We describe a liquid chromatographic technique to determine L-glycerate in body fluids. The method is based on the derivatisation of the L-glycerate by incubation with lactate dehydrogenase and nicotinamide-adenine dinucleotide in the presence of phenylhydrazine. Oxidation of L-glycerate forms beta-hydroxypyruvate which is converted in turn into the related phenylhydrazone. The UV-absorbing derivative is determined using reversed-phase high performance liquid chromatography. The sensitivity was 5 mumol/l and 50 microliters of sample were required. The imprecision relative standard deviation was 4.5% and the recovery was 96.5 +/- 6.8% for L-glycerate in plasma. L-Glycerate concentrations in urine and plasma were less than 5 mumol/l in both normal individuals and patients with glycolic aciduria. In a patient with systemic oxalosis and normal plasma glycolate, plasma L-glyceric acid was 887 mumol/l.