吸烟者体内的硫氰酸盐会干扰诺瓦镁离子选择电极。

Thiocyanate in smokers interferes with the Nova magnesium ion-selective electrode.

作者信息

Rehak N N, Cecco S A, Niemela J E, Elin R J

机构信息

Clinical Pathology Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892-1508, USA.

出版信息

Clin Chem. 1997 Sep;43(9):1595-600.

PMID:9299939

Abstract

Thiocyanate found in serum ordinarily is the metabolite of cyanide that is inhaled with tobacco smoke and ingested with cyanogenic foods. We investigated the effect of the thiocyanate ion (SCN-) on the ionized magnesium (iMg) and ionized calcium (iCa) results determined with the AVL and Nova magnesium and calcium ion-selective electrodes (ISEs). We analyzed saline and pooled serum with added SCN-, and serum from apparently healthy nonsmokers (n = 20) and smokers (n = 20). The mean (and range) of the measured serum SCN- concentration was 0.019 (0.008-0.046) mmol/L for nonsmokers and 0.077 (0.020-0.138) mmol/L for smokers. Only the Nova iMg results decreased with increasing SCN- concentration, and the change was dependent on the baseline iMg concentration. In the absence of Mg, SCN- decreased the voltage response of the Nova Mg ISE to calcium ions. At apparently normal serum iMg and iCa concentrations, the interference by SCN- appeared to be equimolar (iMg = -1.04 x SCN- + 0.52). Thus, the serum SCN- commonly found in smokers causes a significant (P < 0.0001) decrease in the Nova iMg results.

摘要

血清中发现的硫氰酸盐通常是与烟草烟雾一同吸入以及与含氰食物一同摄入的氰化物的代谢产物。我们研究了硫氰酸根离子（SCN⁻）对使用AVL和诺瓦镁离子及钙离子选择性电极（ISEs）测定的离子化镁（iMg）和离子化钙（iCa）结果的影响。我们分析了添加SCN⁻的生理盐水和混合血清，以及来自明显健康的非吸烟者（n = 20）和吸烟者（n = 20）的血清。非吸烟者血清SCN⁻浓度的平均值（及范围）为0.019（0.008 - 0.046）mmol/L，吸烟者为0.077（0.020 - 0.138）mmol/L。只有诺瓦iMg结果随SCN⁻浓度增加而降低，且这种变化取决于基线iMg浓度。在无镁的情况下，SCN⁻降低了诺瓦镁ISE对钙离子的电压响应。在血清iMg和iCa浓度看似正常时，SCN⁻的干扰似乎是等摩尔的（iMg = -1.04×SCN⁻ + 0.52）。因此，吸烟者血清中常见的SCN⁻会导致诺瓦iMg结果显著降低（P < 0.0001）。