Determination of oxalic acid in the solution of glyoxylic acid by HPLC

The determination of oxalic acid in the solution of glyoxylic acid by HPLC.Under the condition of 0.025 mol/L potassium dihydrogen phosphate-0.01 mol/L tetrabutylammonium hydroxide(phosphorous acid to pH=2.0)as mobile phase at 210 nm.The calibration curves showed good linearities in the range of 0.406 4~3.251 2 mmol/L with correlation coefficients of 0.999 7.The average recoveries were 98.3%~100.4% with RSD of 1.06%.The average content of oxalic acid in the solution of glyoxylic acid were 3.22%,with RSD of 1.08%.The method could be applied to the determination of oxalic acid in the solution of glyoxylic acid with good reproducibility and reliability.