Casella I G, Gatta M, Cataldi T R
Dipartimento di Chimica, Università degli Studi della Basilicata, Potenza, Italy.
J Chromatogr A. 2000 May 5;878(1):57-67. doi: 10.1016/s0021-9673(00)00274-0.
A nickel-based composite electrode obtained by anodic electrodeposition of nickel (III) oxyhydroxide film on the gold electrode substrate was characterized as an amperometric sensor and successfully applied to the determination of underivatised amino acids in flow-through systems. The electrodeposition of nickel oxyhydroxide films was obtained by cycling a gold electrode between 0.0 V and +1.0 V vs. a saturated calomel electrode in a 80 microM Ni2+ solution buffered at pH 10 with NaHCO3/Na2CO3. The resulting Au-Ni composite electrode exhibits good stability in alkaline medium and can be used as an amperometric sensor of underivatised amino acids at a fixed applied potential (+0.55 V vs. Ag/AgCl). The detection limits (S/N=3) for all investigated compounds ranged between 5 and 30 pmol injected, while the linear ranges spanned over two or three orders of magnitude. The contents of several free amino acids in two sample cheeses from different brands were evaluated by calibration graphs.
通过在金电极基底上阳极电沉积氢氧化氧镍膜获得的镍基复合电极被表征为安培传感器，并成功应用于流通系统中未衍生化氨基酸的测定。氢氧化氧镍膜的电沉积是通过在含有80 microM Ni2+且用NaHCO3/Na2CO3缓冲至pH 10的溶液中，将金电极相对于饱和甘汞电极在0.0 V和 +1.0 V之间循环来实现的。所得的金 - 镍复合电极在碱性介质中表现出良好的稳定性，并且可以在固定施加电位（相对于Ag/AgCl为 +0.55 V）下用作未衍生化氨基酸的安培传感器。所有研究化合物的检测限（S/N = 3）在注入5至30 pmol之间，而线性范围跨越两到三个数量级。通过校准曲线评估了来自不同品牌的两种样品奶酪中几种游离氨基酸的含量。
