Lähdesmäki I, Kubiak W W, Lewenstam A, Ivaska A
Process Chemistry Group, c/o Laboratory of Analytical Chemistry, Abo Akademi University, FIN-20500 Turku-Abo, Finland.
Talanta. 2000 Jun 21;52(2):269-75. doi: 10.1016/s0039-9140(00)00330-1.
The main focus of this article is on the interferences encountered when an amperometric ammonia sensor is used in matrices that are typical in clinical samples. The sensor is tested in presence of such interferences and ways to suppress them by sensor modification are presented. Two modification procedures are evaluated by comparing the stabilities, detection limits and signal-to-noise ratios of such sensors. Further, the issue of the ammonia-sensing mechanism of the polypyrrole electrode is addressed. Evidence is shown that a mobile counterion may be required for proper sensor operation. Such evidence supports the idea that polypyrrole undergoes a reversible redox reaction when ammonia is detected at submillimolar concentrations.
本文的主要重点是在临床样本中典型的基质中使用安培型氨传感器时遇到的干扰。在存在此类干扰的情况下对传感器进行了测试，并提出了通过传感器改性来抑制干扰的方法。通过比较此类传感器的稳定性、检测限和信噪比，对两种改性程序进行了评估。此外，还讨论了聚吡咯电极的氨传感机制问题。有证据表明，适当的传感器操作可能需要一种可移动的抗衡离子。此类证据支持了这样一种观点，即当在亚毫摩尔浓度下检测氨时，聚吡咯会发生可逆的氧化还原反应。
