A modification of the p‐anisidine method for the determination of free and total gossypol

Summary A modification of the Pons and Guthrie method for determining free gossypol in cottonseed materials is presented. The use of aniline, rather than p‐anisidine, as the color‐producing reagent is necessary if meals containing dianilinogossypol are to be analyzed correctly. Increasing the reaction temperature eliminates a serious weakness in the method and results in greater accuracy. The proposed method is applicable to all types of cottonseed meal now marketed. A slight modification of the Pons method for total gossypol is also presented. By doubling the strength of the oxalic acid used to hydrolyze bound gossypol and by using aniline to develop the color, the method is made applicable to chemically treated meals containing dianilinogossypol.