An environmental friendly flow-injection procedure for on line extraction and spectrophotometric determination of gossypol in cottonseed meal

Abstract

A fast, simple and inexpensive procedure is described for the determination of gossypol in cottonseed meal. The procedure is based on a flow injection analysis system and a complexation reaction with spectrophotometric detection at 620 nm. A fluidized bed column was used to implement the on line that was coupled to the extraction flow system in order to analyze the solid samples directly. A linear response was observed from 0.96 to 3.85 mmol L-1, and the detection limit, the coefficient of variation and the sampling rate were estimated at 100 µmol L-1 (99.7% confidence level), 1.90% (n = 20) and 30 h-1, respectively. The reagent consumption was 1.08 mg of Fe(NO3)3, with a volume of 20 mL of effluent per determination. Analyses of the results of commercial samples were consistent with through the official procedure of detoxification of cottonseed meal as described by American Oil Chemists’ Society (AOCS) at the 95% confidence level.