背景:碘是合成甲状腺激素的基本要素。因此,碘供应的可靠标志很重要。碘主要通过肾脏排泄,而且还通过唾液腺.我们的目的是介绍一种新的简单的唾液碘浓度(SLIC)测定方法。
方法:使用了在0-400µg/L范围内的过氧二硫酸铵(AP)在微孔板上进行Sandell-Kolthoff反应的自制化学品和标准品。测试了水基标准(WBS)和基于人工唾液的标准(ASS)对标准曲线的适用性。我们遵循方法验证的标准,确定使用的AP的浓度,并将我们的结果与电感耦合等离子体质谱法(ICP-MS)进行比较。
结果:WBS给出了比ASS更可靠的结果,因为ASS低估了碘浓度。LoB为6.5微克/升,LOD12.0µg/L,因此分析范围为12-400µg/L碘浓度下的测定内和测定间不精确,即20、100、165和350µg/L分别为18.4、5.1、5.7和2.8%,分别,20.7%、6.7%、5.1%和4.3%,分别。AP的合适摩尔浓度为1.0mol/L,与1.5mol/L没有差异(浓度为40、100和150µg/L的样品的P值,分别为0.761、0.085和0.275),而使用0.5mol/L时变化显著(P<0.001)。唾液样品可以稀释至1:8。硫氰酸盐和咖啡因的干扰高达193.5mg/L。我们的原始方法与ICP-MS相当。Spaerman系数为0.989(95%CI:0.984-0.993)。
结论:测定SLIC的新方法与ICP-MS非常吻合,并且易于使用。
BACKGROUND: Iodine is an essential element for the synthesis of thyroid hormones. Therefore, a reliable marker of iodine supply is important. Iodine is predominantly excreted via kidneys, but also via salivary glands. Our aim was to introduce a new and simple method for determination of salivary iodine concentration (SLIC).
METHODS: Self-prepared chemicals and standards for Sandell-Kolthoff reaction on microplate with ammonium peroxydisulfate (AP) in the range 0-400 µg/L were used. Suitability of water-based standards (WBS) and artificial saliva-based standards (ASS) for standard curve were tested. We followed standards for method validation, defined concentration of used AP and compared our results with Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
RESULTS: WBS gave more reliable results than ASS as an underestimation of iodine concentration was found for ASS. LoB was 6.5 µg/L, LoD 12.0 µg/L, therefore analytical range was 12-400 µg/L. Intra- and inter-assay imprecisions at iodine concentrations, namely 20, 100, 165, and 350 µg/L were 18.4, 5.1, 5.7, and 2.8%, respectively, and 20.7, 6.7, 5.1, and 4.3%, respectively. Suitable molarity of AP was 1.0 mol/L and showed no difference to 1.5 mol/L (P values for samples with concentration 40, 100, and 150 µg/L, were 0.761, 0.085, and 0.275, respectively), whereas there was a significant change using 0.5 mol/L (P<0.001). Saliva samples could be diluted up to 1:8. There was no interference of thiocyanate and caffeine up to 193.5 mg/L. Our original method was comparable to ICP-MS. Spaerman coefficient was 0.989 (95% CI: 0.984-0.993).
CONCLUSIONS: The new method for SLIC determination is in excellent agreement with ICP-MS and easy-to-use.