Voltammetric determination of cadmium(II) using a chemically modified electrode.
An 1-(pyridylazo)-2-naphthol modified glassy carbon electrode has been investigated as sensor for the measurement of trace levels of Cd2+. Cd2+ is deposited on the surface of a PAN modified glassy carbon electrode at -1.10 V (vs. SCE) via forming Cd2+-PAN and subsequent reduction at the electrode. In the following step, Cd-PAN is oxidized, and voltammograms are recorded by scanning the potential in a positive direction. Calibration plots were found to be linear in the range 2 x 10(-8) mol/L to 8 x 10(-7) mol/L. The detection limit was 5 x 10(-10) mol/L, and the coefficient of variation, determined on one single electrode at a concentration of 5 x 10(-7) mol/L, was calculated to be 3.2% (n = 5). Using this new kind of modified electrode, trace levels of Cd(II) in water samples were determined; the average recovery was calculated to be 98.78%.
Hu
S
S
Department of Chemistry, Wuhan University, P.R. China.
Wu
K
K
Yi
H
H
Dai
X
X
Cui
D
D
D002104:Cadmium / Q000032:analysis*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D015386:Hazardous Substances / Q000032:analysis*; D008670:Metals / Q000032:analysis; D009284:Naphthols / Q000737:chemistry*; D012623:Seawater / Q000737:chemistry; D013054:Spectrophotometry, Atomic; D014873:Water Pollutants / Q000032:analysis*
D015386:Hazardous Substances; D008670:Metals; D009284:Naphthols; D014873:Water Pollutants; D002104:Cadmium; C041728:1-(2-pyridylazo)-2-naphthol