Voltammetric determination of trace level of cadmium in mussels and seawaters by a lacunar apatite-modified carbon electrode

An electrochemical sensor was fabricated by potassium lacunar apatite (KCaAP). This sensor, coupled with differential pulse anodic stripping voltammetry, could provide a means for a relatively inexpensive detector for trace levels of cadmium. The analytical performance was evaluated with respect to the quantity of modifier in the paste, preconcentration time and the stripping voltammetric parameters. A linear calibration graph was obtained in the concentration range 7.0 × 10–7–1.0 × 10–4 mol L−1 Cd (II) with a detection limit of 4.86 × 10−8 mol L−1. For eight repetitions, the differential pulse voltammetric response was repeated with 7.15% and 4.69% expressed as relative standard deviations in 9.0 × 10−6 and 9.0 × 10−5 mol L−1 of cadmium (II), respectively. The lacunar apatite modified carbon paste electrode (KCaAP-CPE) was applied to the detection of cadmium content in mussels and seawater samples with satisfactory results.