多壁碳纳米管化学修饰玻碳电极用于曲酸的伏安测定

Voltammetric Determination of Kojic Acid with the Multi-wall Carbon Nanotubes Modified Glassy Carbon Electrode

考查了曲酸在多壁碳纳米管化学修饰电板上的电化学行为，相对于裸玻碳电板，多壁碳纳米管化学修饰电极测定曲酸的峰电流明显增加。示差脉冲伏安法测定曲酸的线性范围为1．0×10^-5～1．0×10^-3mol·L-1，检出限（3S／N）为5．0×10^-6mol·L-1。用此修饰电极连续测定一种酱油样品的曲酸含量，得到一致的结果，而用裸玻碳电极时所得结果明显降低，由此可见，修饰电极的稳定性显著提高。方法用于酱油、黄酒等复杂样中曲酸的直接测定，加标平均回收率为99．5％，测定值的相对标准偏差均小于5％。

Electrochemical behavior of kojic acid at the multi-wall carbon nanotubes （MWCNT＇ s） modified glassy carbon electrode （GCE） was studied voltammetrically. As compared with the bare GCE, a remarkable increase of anodic peak current of kojic acid was obtained at the modified electrode. Linear relationship was found between values of peak current （Ip） and concentration of kojic acid in the range of 1.0×10^-5 -1.0×10^-3mol · L-1 as determined by the differential pulse voltammetry （DPV）. Detection limit （3S/N） of the method was found to be 5.0×10^-6mol · L-1. Test for stability of the MWCNT＇s modified GCE was made by successive determination of kojic acid in a soy sample and consistent results were obtained, while the results obtained by using bare GCE were decreased apparently. The proposed method was used for determination of kojic acid in some complex samples, e. g. , soy and millet wine, giving values of RSD＇s （n=5） less than 5%, and of average recovery 99. 5%.