An electrochemical sensor based on a clay-coated screen-printed electrode for the determination of arbutin

A preanodized clay-coated screen-printed electrode (CCSPE) is used for the determination of arbutin (hydroquinone-beta-D-glucopyranoside) in cosmetic bleaching products by square-wave voltammetry. The peranodization process e xhibits a marked enhancement in the current response of arbutin at the CCSP E. Compared to the performance at a preanodized SPE, the coating of clay wa s found to further improve the sensitivity and reproducibility. Under optim ized conditions, the linear range for arbutin detection is up to 90 mu M (c orrelation coefficient=0.999) in pH 10.0 ammonium buffer with a detection l imit of 0.18 mu M (S/N=3). The electrode can be either disposable or reused since renewal provides good reproducible surfaces. Quantitative analysis w as performed by standard addition for the arbutin content in commercial ava ilable cosmetic bleaching products. (C) 2000 Elsevier Science B.V. All righ ts reserved.