Electrochemical Determination of Sudan I Based on Enhancement Effect of Sodium Dodecyl Benzene Sulfonate

The electrochemical behavior of Sudan I was examined by means of linear sweep voltammetry(LSV),cyclic voltammetry(CV)and chronocoulometry.At the carbon paste electrode(CPE),a non-sensitive oxidation peak was observed for Sudan Ⅰ.However,the oxidation peak current of Sudan Ⅰ remarkably increased after sodium dodecyl benzene sulfonate(SDBS)was added at a low concentration,suggesting that SDBS exhibtis an efficient enhancement effect towards Sudan Ⅰ.The results obtained from chronocoulometry indicate that SDBS significantly improves the adsorption of Sudan Ⅰ at the CPE surface.The experimental parameters such as pH value,concentration of SDBS,accumulation potential and time were optimized,and a new electrochemical method was then developed for the determination of Sudan Ⅰ.The linear range was from 2.0×10-7 to 1.5×10-5 mol/L,and the limit of detection was 6.0×10-8 mol/L after 180 s accumulation.Finally,this method was successfully used to detect Sudan Ⅰ in hot pepper and ketchup food.