Determination of Sudan III in Chili Products by Linear Sweep Polarography

[Objective]The study amied to establish the determination method for sudanⅢcontents in chili powder by linear sweep polarography. [Method]The linear sweep polarography and cyclic voltammetry methods was used to study electrochemical behavior of sudanⅢ,the determination of the experimental conditions were optimized.[Result]Under the determination condition of BR buffer medium of pH 7.0,a sensitive reduction wave was given by sudanⅢwith its peak potential at -0.93 V(vs.SCE) by linear sweeping polarography.Linear relationship between the 2nd derivative of peak current of the reduction wave and the concentration of sudanⅢwas obtained in the range of 0.8～8.0μmol/L(r = 0.999 3),with a detection limit of 0.388μmol/L.The determination of micro amounts of sudanⅢin chili powder with the average recovery in the range of 95.93%- 105.7%.[Conclusion]The determination method of linear sweep polarography had characters of simple,rapid speed,high sensitivity,which was a rapid determining method suitable to detect the sudanⅢcontents in chili powder.