A streamlined method for determination of total and individual glucosinolates in rapeseeds using spectrophotometry and high performance liquid chromatography was developed in this study. The rapeseeds were extracted using 70% methanol solution and purified by a strong anion exchange column. The sample solution was divided into two aliquots. One part was hydrolyzed to determine the total glucosinolates content by evaluating the loss of chromogenic ferricyanide at 420 nm. The quantitative analytical method of total glucosinolates was fully validated with respect to the linearity (r2 >0.995), sensitivity, precision, accuracy (the recovery between 91.7-108%), and robustness (the relative standard deviation ˂ 5.23%). The other part was enzymatic hydrolyzed by sulfatase, with optimized reaction time of one hour to establish the desulfoglucosinolate profiles by high performance liquid chromatography. The concentrations of the individual glucosinolates were calculated based on the total glucosinolate value and their response factors. The developed method was successfully applied to determine the content of individual glucosinolates in rapeseeds without an internal standard. The newly established method is simple, fast and reliable on the quantitation of glucosinolates in rapeseeds.

Keywords:  Total Glucosinolates; Individual glucosinolates; Rapeseed; Desulfo-Glucosinolates; HPLC; Spectrophotometry.