Stability of the Gossypol‐Amine Adducts Used for Chromatographic Measurement of Total and Isomeric Gossypol

Abstract

AbstractThe stability of the gossypol amine adducts used for chromatographic determination of gossypol was studied. After extraction and complexation with R‐(−)‐2‐amino‐1‐propanol, the samples were diluted into an acetonitrile/phosphate buffer solution as described in AOCS Recommended Practice Ba 8a‐99. The solutions were then stored under different conditions before being analyzed by reverse‐phase chromatography. Samples stored in the dark at −80 °C or at −20 °C showed little change in peak size over 30 days. Samples stored in the dark at −4 °C or at room temperature showed a measurable reduction in gossypol peak size over the study period. Samples stored in the light at room temperature showed the greatest reduction with only 25% of the initial gossypol detectable after 30 days. The rate of degradation followed first‐order kinetics. The rate of decrease in gossypol peak size did not differ for the different gossypol matrices studied, i.e., cottonseed kernels, cottonseed meal, or pure gossypol‐acetic acid; nor did it differ for the individual gossypol enantiomers. The results indicate that these gossypol Schiff's base adducts can be transported on dry ice before chromatography with minimal concern for their stability.