Bicarbonate Interference with Chloride-Ion-Selective Electrodes

[摘要] Plasma chloride is of value in the assessment of acid/base and electrolyte abnormalities. It is a component in calculation of both the anion gap and strong ion differences. The analytical method used extensively today, particularly in high-throughput analyzers, involves an ion-selective electrode incorporating a quaternary nitrogen compound. This has superseded amperometric titration with silver electrodes, which is not amenable to high-throughput or multianalyte instrumentation, and mercuric thiocyanate-based colorimetric methods, which require disposal of a toxic waste product.In 1986 and 1991, two reports (1)(2) were published that documented marked positive interference by bicarbonate on plasma chloride analyses performed by Hitachi 705 and 717 analyzers. No further reports have been published since then. We suspected that similar problems might be occurring with the Dade Dimension RxL analyzer because of the high frequency of negative anion-gap calculations in samples from patients with metabolic alkalosis. Reviews of external quality assurance data for Dade Dimension RxL analyzers showed …

[学科分类] 过敏症与临床免疫学