摘要
利用溴、碘在HCl介质中对H2O2氧化邻苯二酚紫(PV)反应的催化,与高温热水解分解样品,离子交换预浓集和分离溴、碘相结合,建立了地质样品中溴、碘的测定方法。NO-2也能催化该反应严重干扰溴、碘的测定,加入氨基磺酸可以消除其对测定的影响。工作曲线在0~4μgBr-和0~2μgI-时符合比尔定律,样品测定下限是02×10-6I-和05×10-6Br-。对于含量为30×10-6Br-和20×10-6I-的样品,其相对标准偏差分别为49%和66%(n=12)。
A kinetic spectrophotometric method for the determination of bromide and iodide based on their catalytic effects on oxidation of pyrocatechol violet by hydrogen peroxide in HCl solution and sample digestion by high temperature hydrolysis is described in this paper. The Beers law is obeyed in ranges of 0~4 μg for Br - and 0~2 μg for I -. The limits of detection for Br - and I - in geological samples are 0.5×10 -6 and 0.2×10 -6 respectively. The interferences of NO - 2 on the determination for both elements are removed by the addition of sulfamic acid in sample solutions. The method has been applied to the determination of Br - and I - in geological samples with precision of 4.9% RSD for Br - and 6.6% RSD for I -( n =12).
关键词
动力学
分光光度法
溴
碘
地质样品
kinetic spectrophotometric method, bromide, iodide