The method is applicable to cottonseed and cottonseed meals and cakes. The method consists in extracting of the compound in the presence of 3-aminopropane-1-ol, either with a mexture of 2-propanol and hexane for the determination of free gossypol or with dimethylformamide for the determination of total gossypol. Conversion to gossypol-dianiline using aniline, and measurement of the absorbance at the wavelength of maximum absorbance (between 435 and 445 nm).