Fibrinogen-coated bismuth film electrodes for voltammetric analysis of lead and cadmium using the batch injection analysis

This work reports the application of fibrinogen-coated bismuth films deposited on carbon paste electrodes (Fbg-BiFEs) for the simultaneous determination of trace amounts of lead and cadmium by square-wave anodic stripping voltammetry, combined with a batch injection analysis technique (BIA-SWASV). The batch injection analysis system provides the advantages of rapid and simple electroanalysis of microliter samples. Its use in combination with Fbg-BiFEs allowed the determination of metals at trace levels in environmental samples, given that the surfactant interference observed with stripping analysis at bismuth electrodes could be minimized by use of a fibrinogen coating. The analytical characteristics, namely sensitivity, detection limits, and resistance to surfactants in the anodic stripping voltammetry of lead and cadmium, were investigated in acetate buffer. The resulting limits of detection were 0.2 mu g L-1 and 0.1 mu g L-1, for Cd and Pb respectively. Finally, the system based on Fbg-BiFEs combined with BIA-SWASV was applied to different real samples ( tap water and tea samples) for analysis of trace metals with satisfactory results.