Chemiluminescence Determination of Gossypol at Trace Levels Using Flow Injection as Sample Introduction Techniques

A simple and sensitive flow injection method with chemiluminescence (CL) detection is developed for the determination of gossypol at trace levels. The method is based on the reaction of luminol with ferricyanid in a sodium hydroxide medium sensitized by gossypol. Under the optimum conditions. the CL intensity is proportional to the concentration of gossypol over the range of 1.11 X 10(-17)-2.78 x 10(-16) M in an acidic solution and 8.00 x 10(-11)-7.39 x 10(-8) M in a neutral solution with correlation coefficients of 0.9983 and 0.9905, respectively. The detection limit is 1.48 x 10(-18) M (3 sigma). The proposed method has been applied to the determination of gossypol in cottonseeds and pharmaceutical preparations with satisfactory results. The CL mechanism is discussed by examining the CL emission spectrum and the effect of various free radical scavengers on the CL emission intensity.