Niwa O, Tabei H, Solomon B P, Xie F, Kissinger P T
NTT Basic Research Laboratories, Kanagawa, Japan.
J Chromatogr B Biomed Appl. 1995 Aug 4;670(1):21-8. doi: 10.1016/0378-4347(95)00145-9.
The detection limit of catecholamines can be lowered by using a carbon-based interdigitated array (IDA) microelectrode as a detector for liquid chromatography (LC). The IDA electrode is more sensitive than conventional glassy carbon electrodes due to the high current density caused by radial diffusion at each microband, and redox cycling between two microband arrays. Since the number of redox cycles increases at lower flow-rates, the carbon IDA is particularly useful for microbore LC. In an LC system with a 1-mm microbore column and a carbon IDA electrode, the peak height of dopamine (DA) and DOPAC did not decrease with decreasing flow-rate because of this redox cycling. A low detection limit of 5 fg (32 amol) and 9.6 fg (57 amol) was obtained for DA and DOPAC due to the high current density and low background noise level (0.1 pA) at the carbon IDA electrode. The total charge generated by oxidizing DA at the anodic array was more than the value calculated by assuming that all the DA molecules were oxidized.
通过使用碳基叉指阵列（IDA）微电极作为液相色谱（LC）的检测器，可以降低儿茶酚胺的检测限。由于每个微带处径向扩散以及两个微带阵列之间的氧化还原循环导致的高电流密度，IDA电极比传统的玻碳电极更灵敏。由于在较低流速下氧化还原循环的次数增加，碳IDA对于微径LC特别有用。在具有1毫米微径柱和碳IDA电极的LC系统中，由于这种氧化还原循环，多巴胺（DA）和3,4-二羟基苯乙酸（DOPAC）的峰高不会随着流速降低而降低。由于碳IDA电极处的高电流密度和低背景噪声水平（0.1 pA），DA和DOPAC的检测限低至5 fg（32 amol）和9.6 fg（57 amol）。在阳极阵列处氧化DA产生的总电荷超过了假设所有DA分子都被氧化所计算的值。
