Cox J A, Jaworski R K
Anal Chem. 1989 Oct 1;61(19):2176-8. doi: 10.1021/ac00194a012.
Cyclic voltammetry of a mixture containing 0.2 mM Na2IrCl6, 0.1 mM PdCl2, 0.2 M K2SO4, and 0.1 M HCl between 1.2 and -0.3 V vs Ag/AgCl for five cycles at 50 mV s-1 yields a stable film on a glassy carbon electrode. The reduction of hydrogen peroxide in 0.1 M KCl is diffusion controlled at that modified electrode. Calibration curves obtained at a 100 mV s-1 scan rate are linear in the range 0.2-1.8 mM H2O2. The slope, 28 microA L mmol-1, is independent of film thickness. Since dissolved oxygen is reduced at about the same potential as H2O2, -0.3 V, at the modified electrode, it will act as an interferent in solutions that are not deaerated; however, the currents are additive. A second limitation of the described procedure is that with the KCl electrolyte the immobilized film must be reoxidized prior to each measurement. Preliminary data are described which suggest that this problem is alleviated by switching to a basic supporting electrolyte.
在玻碳电极上，含有0.2 mM Na2IrCl6、0.1 mM PdCl2、0.2 M K2SO4和0.1 M HCl的混合物在相对于Ag/AgCl为1.2至 -0.3 V的电位范围内，以50 mV s-1的扫描速率进行五个循环的循环伏安法，会产生一层稳定的薄膜。在该修饰电极上，0.1 M KCl中过氧化氢的还原受扩散控制。在100 mV s-1的扫描速率下获得的校准曲线在0.2 - 1.8 mM H2O2范围内呈线性。斜率为28 μA L mmol-1，与膜厚度无关。由于在修饰电极上溶解氧在与H2O2大致相同的电位 -0.3 V处被还原，因此在未除气的溶液中它将作为干扰物；然而，电流是相加的。所描述方法的第二个局限性是，使用KCl电解质时，固定化膜在每次测量之前必须重新氧化。文中描述了初步数据，表明通过切换到碱性支持电解质可以缓解这个问题。
