Determination of glyoxylic acid in similar organic mixtures using HPLC technique has been successful in using refractive index and photo diode array detectors, respectively. Another method required the conversion of glyoxylic acid into one of its derivatives with 2,4-dinitrophenylhydrazine, . Glyoxylic acid in other mixtures was also determined by this technique however using a more sensitive detector; the fluorescence detector, after converting glyoxylic acid into a fluorocarbon derivative with detection limit reaching 5 nanomol/L, .