Determination of sibutramine with a new sensor based on luminol electrochemiluminescence

A flow injection electrochemiluminescence (FI-ECL) analysis method for the determination of sibutramine in the presence of luminol was studied under conventional cyclic voltammetry in alkaline Na2CO3-NaHCO3 buffer solution (pH 8.0-12.0). This method is based on the enhanced ECL of luminol-sibutramine. Meanwhile, in order to overcome the drawbacks of conventional cells, a FI cell was designed, which is reusable and has a great improvement in sensitivity and selectivity for ECL analysis. Under the optimal experimental conditions, the enhanced ECL intensity was linearly related to the concentration of sibutramine in the range 1.0 x 10(-8)-1.0 x 10(-6) g mL(-1) with a detection limit of 2.48 x 10(-9) g mL(-1) and a correlation coefficient (R) of 0.9995. The relative standard deviation (RSD) for 1.0 x 10(-7) g mL(-1) samples was 2.1% (n = 11). The possible mechanism discussed. The proposed FI-ECL method has been successfully applied to the determination of sibutramine in diet pill samples. (C) 2011 Elsevier B.V. All rights reserved.