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在玻碳电极上成功制备了多壁碳纳米管(MWNTs)修饰玻碳电极(GCE),并对其进行显微表征。研究表明,该修饰电极(MWNTs/GCE)对Fe3+具有明显的电催化还原作用。将其用于流动注射不可逆双安培(FI-IB)体系的构建,即:利用Fe3+在MWNTs/GCE上的还原和硫酸羟胺((NH2OH)2.H2SO4)在另一支金电极上的氧化,构建了双安培检测新体系,建立了在外加电压为0 V条件下流动注射双安培法直接测定Fe3+的新方法。在0 V外加电位差下,在6×10-2 mol/L HCl载液中,该还原峰峰电流与Fe3+浓度在4.0×10-3～10-1mg/mL范围内呈良好的线性关系,其线性回归方程为i(nA)=1.4456×105C-582.97(r=0.9992,n=7),方法检出限为8.0×10-4mg/mL(S/N=3)。连续测定1.00×10-2mg/mL的Fe3+标准溶液20次,电流值RSD为2.99%,进样频率为90样/h。该方法具有较高的选择性和灵敏度。对模拟样品中Fe3+含量的测定,结果比较满意。
Multi-walled carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE) was successfully prepared on glassy carbon electrode and its microstructure was characterized. Studies have shown that the modified electrode (MWNTs / GCE) on the Fe3 + significant electrocatalytic reduction. It was applied to the construction of flow-injection irreversible bi-ampere (FI-IB) system by using the reduction of Fe3 + on MWNTs / GCE and the oxidation of hydroxylamine sulfate ((NH2OH) A new double amperometric detection system was established and a new method was established for the direct determination of Fe3 + by flow injection dual amperometry under the applied voltage of 0 V. Under the potential difference of 0 V, the reduction peak current in the 6 × 10-2 mol / L HCl carrier liquid has a good linear relationship with the concentration of Fe3 + in the range of 4.0 × 10-3 ~ 10-1mg / mL. The linear regression equation was: i (nA) = 1.4456 × 105C-582.97 (r = 0.9992, n = 7). The detection limit was 8.0 × 10-4mg / mL (S / N = 3). Continuous determination of 1.00 × 10-2mg / mL of Fe3 + standard solution 20 times, the current value of RSD was 2.99%, the injection frequency of 90 samples / h. The method has high selectivity and sensitivity. The results of the determination of Fe3 + in the simulated samples are satisfactory.