VOLTAMMETRIC DETERMINATION OF CETYLPYRIDIUM CHLORIDE WITH A SILVER ELECTRODE

ABSTRACT

In the presence of l-cysteine (l-cys), cetylpyridium chloride (CPC) exhibited a sensitive cathodic stripping peak at about −1.2 V (vs SCE). The square root of the peak height was linear with CPC concentration over the range of 2 µM to 50 µM, with a slope of 0.124 µA^1/2/µM. This was developed for the determination of CPC concentration. The peak was thought to be generated by l-cys; CPC could catalyze/promote the electrochemical process and thus make the peak grow rapidly. However, other surfactants tested such as cetyltrimethyl ammonium bromide (CTAB) or sodium dodecyl sulfonate (SDS) did not behave so. Conditions such as solution pH, deposition potential and accumulation time were discussed. It was found that the cathodic stripping peak was well defined in 40 mM pH 10.9 sodium phosphate solutions; the optimum deposition potential was 0.5–0.1 V.

Keywords:

• Cetylpyridium chloride
• l-cysteine
• Silver electrode
• Cathodic stripping voltammetry

ACKNOWLEDGMENTS

This work is supported by financial support from Electroanalytical Open Lab of Application Chemistry Institute of Changchun, China.