RESUMO
This paper presents a method for the direct determination of intact glucosinolates in rapeseed by reversed-phase ion-pair liquid chromatography (RILC). The catechin, mercaptoethanol and phytic acid was adopted respectively in sample pretreatment to prevent indole glucosinolates being oxidized. Among them, the effect of mercaptoethanol was the most obvious. The effects of composition and concentration of the mobile phase, the pH of the mobile phase and the column temperature on the retention and the capacity factor of the glucosinolates were studied. The condition of this method by RILC has been set up: column, YWG-C18 H37(10 microns, 250 mm x 4 mm i.d.); mobile phase, 0.02 mol/L KH2PO4 buffer(pH 6) containing 4.5 mmol/L (C4H8)4NBr and CH3CN(90/10, V/V); flow rate, 1 mL/min; detector, UV-226 nm; column temperation, 30 degrees C. In this condition, six glucosinolates were separated completely. The relative correction factors were determined by using sinigrin or benzoic acid as the internal standard. The characteristics of glucosinolates in different kinds of Chinese rapeseed can be determined by this RILC method.
