A silica gel chromatographic procedure adapted to liquid‐scintillation counting of 14 c labelled organic acids from plant material and silage

A method is described for the separation of a wide range of organic acids present in plant material and in silage. The method consists of cold extraction with dilute sulphuric acid, followed by purification of the extract on a silica gel column. The organic acids in the purified extract were separated quantitatively using a continuous gradient‐elution system of eluents through a small silica gel column. The extraction method was found to be more efficient for extracting citric, oxalic and fumaric acids from red clover, than a standard method with ethanol, water and ion‐exchange resins. Most of the acids of the tricarboxylic acid cycle were detected in red clover. An unidentified acid accounted for more than 37% of the organic acidity. The activity of 14 C‐labelled acids could be measured directly on the eluate from the column in combination with a liquid scintillation system.