Differential Pulse Anodic Stripping Voltammetric Determination of Bismuth(III) with 1-(2-Pyridylazo)-2-naphthol and Ionic Liquid Modified Carbon Paste Electrode

In this paper 1-(2-pyridylazo)-2-naphthol (PAN) and ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) were mixed with graphite powder to get a modified carbon paste electrode (PAN-IL-CPE), which was further used for the sensitive determination of bismuth(III). By the co-contribution of the formation of PAN-Bi complex and the accumulation effect of IL, more bismuth(III) was electrodeposited on the surface of the PAN-IL-CPE. Then the reduced Bi was oxidized and detected by differential pulse anodic stripping voltammetry (DPASV) with the oxidation peak appeared at 0.17 V (vs. SCE). Under the optimal conditions the oxidation peak current was proportional to the bismuth(III) concentration in the range from 0.04 to 7.5 μmol L−1 with the detection limit as 3.9 nmol L−1. The proposed method was successfully applied to the stomach medicine sample detection with good recovery.