紫外分光光度法快速测定溶液中微量碘离子

Rapid Determination of Trace Iodide in Solutions by UV Spectrophotometry

本文建立了紫外分光光度法快速测定溶液中微量I-的分析方法,I-浓度在0.005～0.200mmol/L范围内时,在226nm波长处的吸光度与浓度呈良好线性关系,相关系数R=0.9991,检出限为9.909×10-5 mmol/L,分析方法的相对标准偏差(RSD)在0%～0.789%之间,加标回收率在98.65%～100.0%之间。温度、溶液酸碱度以及共存的K+、Na+、Br-、Cl-、SO42-对测定无影响;共存的CO32-、HCO3-干扰很大,可加酸除去;Mg2+、Ca2+的影响可利用相应线性关系进行校正。该方法可用于油田卤水中微量I-的测定。

A rapid UV spectrophotometric method was established to determine trace iodide content in solutions.The linear range of iodide solution at 226 nm is 0.005～0.200 mmol/L.The linear fitting equation is A=12.413c＋0.039 with a correlation coefficient of 0.9991.The detection limit is 9.909×10-5 mmol/L.The RSD（n=6） of the analysis method is 0～0.789%.The recovery for oilfield water sample is 98.65～100.00%.Temperature,solution pH,and the coexisting K＋,Na＋,Br-,Cl-and SO2-4 ions do not affect the detection in general.The coexisting CO2-3 and HCO-3 ions have much interference in the determination,which can be eliminated by acidification.The coexisting Mg2＋ and Ca2＋ ions have an obvious effect on the detection,which can be calibrated through the linear relationships between the absorbance and Mg2＋ or Ca2＋concentrations in solutions with a fixed I-content.The method could be used to determine trace iodide content in oilfield water.