A Robust Method for Iodine Status Determination in Epidemiological Studies by Capillary Electrophoresis

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• 作者：Adriana Nori de Macedo ; Koon Teo ; Andrew Mente ; Matthew J. McQueen ; Johannes Zeidler ; Paul Poirier ; Scott A. Lear ; Andy Wielgosz ; Philip Britz-McKibbin
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：October 21, 2014
• 年：2014
• 卷：86
• 期：20
• 页码：10010-10015
• 全文大小：371K
• ISSN：1520-6882

文摘

Iodine deficiency is the most common preventable cause of intellectual disabilities in children. Global health initiatives to ensure optimum nutrition thus require continuous monitoring of population-wide iodine intake as determined by urinary excretion of iodide. Current methods to analyze urinary iodide are limited by complicated sample pretreatment, costly infrastructure, and/or poor selectivity, posing restrictions to large-scale epidemiological studies. We describe a simple yet selective method to analyze iodide in volume-restricted human urine specimens stored in biorepositories by capillary electrophoresis (CE) with UV detection. Excellent selectivity is achieved when using an acidic background electrolyte in conjunction with dynamic complexation via 伪-cyclodextrin in an unmodified fused-silica capillary under reversed polarity. Sample self-stacking is developed as a novel online sample preconcentration method to boost sensitivity with submicromolar detection limits for iodide (S/N 鈮?3, 0.06 渭M) directly in urine. This assay also allows for simultaneous analysis of environmental iodide uptake inhibitors, including thiocyanate and nitrate. Rigorous method validation confirmed good linearity (R² = 0.9998), dynamic range (0.20 to 4.0 渭M), accuracy (average recovery of 93% at three concentration levels) and precision for reliable iodide determination in pooled urine specimens over 29 days of analysis (RSD = 11%, n = 87).