Cathodic electrochemical analysis of methyl parathion at bismuth-film-modified glassy carbon electrode

Bismuth-film electrode (BiFE) was prepared by ex situ depositing bismuth onto glassy carbon electrode for the detection of organophosphate (OP) pesticides, using methyl parathion (MP) as a model analyte. The sufficiently wide negative potential window available made the BiFE a potentially suitable electrode for application in the field of cathodic electrochemical detection of OPs. The BiFE showed similar or even favorable behavior compared to that of mercury and bare electrode. Operational parameters, including the deposition potential and time of bismuth film, pH of the analytic solution and concentration of surfactant, cetyltrimethyl ammonium bromide (CTAB) have been optimized. Under the optimum experimental conditions, the cathodic voltammetric response was proportional to the concentration of MP range from 3.0 to 100 ng mL(-1), with a correlation coefficient of 0.9981. The detection limit was 1.2 ng mL(-1) (threefold standard deviation of a blank). Due to the easy preparation and regeneration of BiFE together with its good reproducibility and stability, the combination of the promising BiFE and cathodic voltammetric perfortnances opens new opportunity for fast, simple, and sensitive analysis of OP compounds in samples. (c) 2008 Elsevier Ltd. All rights reserved.