Burguera J L, Brunetto M R, Contreras Y, Burguera M, Gallignani M, Carrero P
IVAIQUIM (Venezuelan Andean Institute for Chemical Research), Faculty of Sciences, University of Los Andes, Mérida, Venezuela.
Talanta. 1996 Jun;43(6):839-50. doi: 10.1016/0039-9140(95)01722-4.
A simple head-space (HS) flow injection (FI) system with chemiluminescence (CL) detection for the determination of iodide as iodine in urine is presented. The iodide is converted to iodine by potassium dichromate under stirring in the closed HS vial, and the iodine is released from urine by thermostatting and is carried in a nitrogen flow through an iodide trapping solution. The concomitant introduction of aliquots of iodine, luminol and cobalt(II) solutions by means of a time-based injector into an FI system allowed its mixing in a flow-through cell in front of the detector. The emission intensity at 425 nm was recorded as a function of time. The salting-out of the standard solutions affected the gas-liquid distribution coefficient of iodine in the HS vial. The typical analytical working graphs obtained under the optimized experimental conditions were rectilinear from 0 to 5 mg l(-1) iodine, achieving a precision of 2.3 and a relative standard deviation of 1.8 for ten replicate analyses of 50 and 200 microg l(-1) iodine. However, a second-order process becomes significant at higher iodine concentrations (from 10 to 40 mg l(-1)). The detection limit of the method is 10 microg l(-1) (80 ng) iodine when 8 ml samples are taken. Data for the iodide content of 10 urine samples were in good agreement with those obtained by a conventional catalytic method, and recoveries varied between 101 and 103% for urine samples spiked with different amounts of iodide. The analysis of one sample takes less than 20 min. In the present study the iodide levels found for 100 subjects were 86.8 +/- 19.0 (61-125) microg l(-1), which is lower than the WHO's optimal level (150-300 microg per day).
本文介绍了一种简单的顶空（HS）流动注射（FI）系统，该系统采用化学发光（CL）检测法测定尿样中碘形式的碘化物。在封闭的顶空瓶中搅拌的条件下，碘化物被重铬酸钾转化为碘，通过恒温从尿液中释放出碘，并在氮气流中携带通过碘化物捕集溶液。借助基于时间的进样器将碘、鲁米诺和钴（II）溶液的等分试样同时引入FI系统，使其在检测器前的流通池中混合。记录425nm处的发射强度随时间的变化。标准溶液的盐析作用影响了顶空瓶中碘的气液分配系数。在优化的实验条件下获得的典型分析工作曲线在0至5mg l⁻¹碘范围内呈直线，对50和200μg l⁻¹碘进行十次重复分析时，精密度为2.3，相对标准偏差为1.8。然而，在较高碘浓度（10至40mg l⁻¹）时，二级过程变得显著。当取8ml样品时，该方法的检测限为10μg l⁻¹（80ng）碘。10份尿样中碘化物含量的数据与传统催化法获得的数据高度一致，不同碘化物加标尿样的回收率在101%至103%之间。分析一个样品所需时间不到20分钟。在本研究中，100名受试者的碘化物水平为86.8±19.0（61 - 125）μg l⁻¹，低于世界卫生组织的最佳水平（每天150 - 300μg）。
