Na_(2)EDTA容量法测定高镉次氧化锌烟尘中酸溶锌含量

Determination of Acid-soluble Zinc Content in High Cadmium Secondary Zinc Oxide Smoke by Na_(2) EDTA Volumetric Method

对于高镉次氧化锌烟尘中酸溶锌含量的测定,目前尚未有充分研究。样品中镉含量较高,稀硫酸浸出时,镉与锌通常是同步浸出的,因此会使酸溶锌检测结果偏高;若是样品中镉含量过高,在采用Na_(2)EDTA滴定法测定酸溶锌含量时,镉对指示剂显色产生干扰,造成终点难以辨别。因此,为提升对这类高镉样品中酸溶锌含量检测的准确度,同时也避免再次采用火焰原子吸收法检测镉含量以减镉,从而提升检测酸溶锌的效率,文章采用加入适量碘化钾的方式,对高镉次氧化锌烟尘中酸溶锌的含量进行测定。

The determination of acid-soluble zinc content in high cadmium suboxide fumes has not been fully studied.The content of cadmium in the sample is relatively high.When leaching with dilute sulfuric acid,cadmium and zinc are usually leached simultaneously,so the detection result of acid-soluble zincare high.When the cadmium interferes with the color development of the indicator,it is difficult to distinguish the end point.Therefore,in order to improve the detection accuracy of acid-soluble zinc content in such high-cadmium samples,and also avoid using flame atomic absorption mothod to detect cadmium content to reduce cadmium,so as to improve the detection efficiency of acid-soluble zinc,the content of acid-soluble zinc in high cadmium secondary zine oxide fume was determined by adding appropriate amount of potassium iodide.