A Radio-Gas Chromatographic Method for Determining the Specific Radioactivity of Glycolic Acid in 14C-Labeled Leaf Tissue
A method for the extraction and quantitative determination of both the mass and radioactivity of glycolic acid from 14C-labeled leaf tissue is described. The recoveries of both mass and radioactivity from standard [1-14C]glycolic acid solutions averaged 98%, and recovery of radioactivity added to plant samples as [1-14C]glycolic acid was over 90% after the complete procedure. The method was reliable with total samples containing as little as 130 nmol of glycolic acid.The mass of glycolic acid recovered from sunflower leaf tissue was proportional to the amount of tissue extracted. In experiments with different plant material, the amount of glycolic acid varied between 530 and 1120 nmol/dm2 of leaf tissue. The specific radioactivity of the glycolic acid in sunflower leaf tissue during photosynthesis in 14CO2 was never more than 20% of the specific radioactivity of the 14CO2 supplied.