| Abstract: | Abstract The electrochemical behavior of Colour Index Acid Blue 120 at carbon paste electrode is studied with cyclic voltammetry and square wave voltammetry for the first time. Two irreversible oxidative peaks at 0.61 V (Pa,1) and 0.90 V(Pa,2) (both vs. SCE) are found at a scan rate of 0.1 V/s. Their electrode processes are both adsorption-controlled with two electrons and two protons participating. The peak currents of the Pa,1 are proportional to the concentration of Colour Index Acid Blue 120 in the range of 2.08–20.80 µM and 62.4–520.0 µM. The coexisting substances such as inorganic ions and fatty alcohol polyoxyethylene ether do not interfere with the determination. The method is applied to the determination of dye-uptake for Colour Index Acid Blue 120 dyeing silk. The results are in good agreement with the spectrophotometric method. |
