Flow injection analysis of zinc pyrithione in hair care products on a cobalt phthalocyanine modified screen-printed carbon electrode.

Zinc pyrithione (ZPT) is an antibacterial and antifungal reagent that is often utilized for the antidandruff activity in hair-care shampoos with a composition level up to 1% in the formulation. It has some adverse effects to human and animal if consumed orally. A disposable type of cobalt phthalocyanide modified screen-printed carbon electrode (CoPc/SPE) in couple with flow injection analysis (FIA) was developed for easy and selective analysis of ZPT in commercial hair-care products. Under the optimized FIA conditions, the CoPc/SPE yielded a linear calibration plot in the window of 6-576muM with sensitivity and detection limit of 1.65nAmuM(-1) and 0.9muM (i.e. 1.42pg in 5mul sample loop), respectively, in 0.1M KOH solution at an applied potential of 0.3V versus Ag/AgCl. Since the approach is simple, easy, selective, and inexpensive, it offers a potential application of daily ZPT analysis in hair-care products.