Extraction and reverse‐phase high‐pressure liquid chromatography of gibberellic acid in soil

Abstract Several aqueous extractants buffered above pH 6.5 were evaluated for their ability to extract gibberellic acid from a Xerollic Calciorthid. More than 90% of the GA3 added to soil was recovered with 0.01 M KH2PO4, pH 7.4. Gibberellic acid in soil extracts concentrated under vacuum was determined by reverse‐phase high‐pressure liquid chromatography (HPLC) by comparing the reproducible GA3 peak areas with those of standards prepared in the same background solution.