关键词: 碳糊电极, 碳纳米管, 线性扫描伏安法, 碘酸根

Abstract: A highly-sensitive and mercury-free method of determining iodate ion in table salt was established based on carboxylic carbon nanotubes modified carbon paste electrode.In 0.1 mol/L NaOH solution,there was a sensitive cathodic stripping peak on voltammograms.The stripping peak potential was-0.52 V when accumulation time of IO-3 at the modified electrode was 60 s and the potential scan rate was 300 mV/s.There was a good liner relationship between the peak current and IO-3 concentration in the range of 8.0×10-10 ～ 5.0×10-8 mol/L and 1.0×10-7 ～ 3.0×10-6 mol/L with the correlation coefficient of 0.999 and 0.998,respectively.The detection limit was 1.0 × 10-11 mol/L.This proposed method had been applied for determination of IO-3 content for the table salt sample and the average recovery was 101.1%.The results of CV test that indicated the electrochemical reaction of iodate ion at the modified electrode was irreversible.The standard rate constant of the cathodic electrode reaction was determined to be 0.0109 cm·s-1.

Key words: carbon paste electrode, carbon nanotubes, linear sweep voltammetry, iodate ion