Determination of trace nickel in water samples with multi-wall carbon nanotube-CdTe quantum dots composite modified electrode
MING Liang, XI Xia
1. Xinglin College, Nantong University, Nantong 226007, China;
2. School of Chemistry and Chemical Engineering, Nantong University, Nantong 226007, China
Abstract：A linear sweep stripping voltammetry for the determination of trace nickel in water samples was developed by using self-made multi-wall carbon nanotube (MWCNT)-CdTe quantum dots (QDs) modified glassy carbon electrode (GCE) and optimizing the determination conditions such as supporting electrolyte and pH, the amount of modifier, accumulation potential and time. The results showed that an anodic stripping peak with high sensitivity and good shape appeared at -0.27 V for nickel after 5 min accumulation at -1.10 V at pH 8.0 NH4Cl-NH3稨2O buffer solution, and the stripping peak current varied linearly with the concentration of Ni2+ over the range of 3.0?10-8 to 4.0?10-5 mol/L with a detection limit of 1.0?10-8 mol/L. The method was applied to the determination of trace nickel in the actual water samples. The results were consistent with those obtained by atomic absorption spectrometry, and the relative standard deviation were between 1.8% and 3.6% with recoveries between 99% and 104%.
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