Study on the electrochemiluminescent behavior of menadione sodium bisulfite in presence of luminol

Menadione sodium bisulfite (MSB) is a stable water-soluble derivative of Vitamin K3, which is found to be able to enhance the ECL of luminol at potential of 0.88 V in phosphate buffer solution. The conditions for the enhanced ECL, such as the selection of the type of buffer solution, applied potential mode, scanning rate, the effect of pH and concentration of luminol have been investigated in detail in this paper. Under the optimum conditions, the enhanced ECL intensity is linear with the concentration of MSB over a wide range, the detection limit for MSB is 3.0 × 10−7 mol/L. The proposed method has been applied to determine the MSB in the commercial injection samples. A possible mechanism for the enhanced ECL of luminol by MSB has also been proposed.