Determination of glycolic acid released from marine phytoplankton by post-derivatization gas chromatography-mass spectrometry

In order to ensure a qualitative and quantitative determination of one among the various compounds that constitute the dissolved organic carbon in the oceans, a gas chromatographic method is described which allows precise determination of glycolic acid in sea water, released from marine phytoplankton during photorespiration. Glycolic acid is extracted from sea water using ethyl acetate and concentrated by solvent evaporation. Chromatographic separation is achieved using a capillary column, after derivatization with bis trimethylsilyl trifluoroacetamide. Flame ionization detection is used in routine measurements giving a quantitative assay for glycolic acid concentration. Identification of separated compounds is improved by on-line mass spectrometry. This method has been developed for use in marine ecology, but could be adapted for microalgal physiology experiments.