Determination of glyoxylic acid and maleate by high performance liquid chromatography with photodiode array detectors

A precolumn-derivatization method was applied to determine glyoxylic acid and maleate in high performance liquid chromatography(HPLC) was established.The HPLC with photodiode array detection(PAD) was performed on a Shim-pack VP.ODS column(250 mm×4.6 mm I.D.,5 μm).The mobile phase was CH3OH-0.1 mol/L NaH2PO4 buffer solution 5∶95(v/v),of which NaH2PO4 buffer solution was adjusted to pH 2.98 using H3PO4.The flow rate was 1.0 mL/min at the column temperature of 40 ℃ and the detection wave length was 195 nm.The linear range of glyoxylic acid was 79.6~26 660 mg/L while that of maleate was 9.3~7 864 mg/L.The detection limit of glyoxylic acid and maleate was 39.4 mg/L and 4.7 mg/L,respectively.The relative standard deviations(RSD) of inter and intra-day precision experiments were 0.22%,0.46% and 0.02%,0.03%.