Abstract: On the basis of the reaction of sulfate with standard barium in water solution, an indirect method for the determination of total amount of thioglucosides in rapeseed by Zeeman AAShas been developed.The operating conditions are as following, wavelength 553.6 nm, lamp curent 10mA, silt width 1.3 nm, burner height 7 mm, flow rate of air and acetylene 9.4 L/min and 2.5 L/min, respectively.The method can be outlined as follows:a known weight sample of rapeseed is placed in a constant temperature bath(55℃)for an hour, after enzymolysis, put it into boiling water for 5 min, remove residure by filtration, dilute the filtrate to a definite volume, take a suitable aliquot of the filtrate to a calibrated centrifuge tube, add a given amount of barium, place the tube in boiling water for 5 min, cool, dilute to mark, mix, determine the excess barium by AAS.Rapeseed sample containing different amount of thiogluoosides from 35.9 to 98.2 μmol/g are analyzed, the standard deviations are 2.72 to 7.83 μmol/g, coefficients of variation are 0.0354 to 0.174, and the method is compared with volumetric analysis, the results obtained are satisfactory, the regression equation is Y = 12.836 + 0.7838X the correlation coefficient is 0.935.

Key words: AAS, Rapeseed, Enzymolysis, Thioglucoside