Sensitive Determination of Trace Pb²⁺ in Seawater Using Columnar Glassy Carbon Electrode

Abstract

We herein report a mercury-free approach for the sensitive determination of trace Pb 2+ in seawater using differential pulse stripping voltammetric (DPSV) method with a novel columnar glassy carbon electrode (CGCE). Compared with the conventional disk glassy carbon electrode with the same diameter, it has much larger electrochemical area (0.627 ± 0.003 cm 2 ). The CGCE shows good accumulation ability and consequently acceptable behavior which makes it suitable as a working electrode in the DPSV determination of Pb 2+ with the great advantage of the avoidance of harmful mercury. Using acidified artificial seawater as supporting electrolyte, there was a good linear relationship between the peak currents and the concentration of Pb 2+ in the range of 0.6~140.0 mg L -1 with a detection limit of 0.3 µg/L (S/N = 3) when the accumulation time was 300 s. The method was employed to determine trace levels of Pb 2+ in real seawater samples successfully.

Review—Ion Interference and Elimination in Electrochemical Detection of Heavy Metals Using Anodic Stripping Voltammetry

“…But as interference ions, their existence posed a threat to accuracy of detection. Zhang et al 35 found that the same concentration of Hg 2+ increased the peak current of 10 μg l −1 Pb 2+ by 28.6% in acidified artificial seawater with pH 1.36. Another research also discovered that the current response of Pb increased when 100 μg l −1 of Bi 3+ was present, as shown in Fig.…”