论文部分内容阅读
本文研究了分光光度法测定聚合硫酸铁絮凝剂中痕量镉的新方法并探讨了显色反应机理。本法是利用分光光度法测定聚合硫酸铁絮凝剂中痕量镉。显色剂为罗丹明B和碘化钾。表面活性剂为聚乙烯醇(PVA)。光度显色反应灵敏度高 ,其最大吸收波长为 60 7nm。表观摩尔吸光系数为 4 99× 1 0 5L·mol- 1 ·cm- 1 。桑德尔灵敏度为 2 2 5× 1 0 - 4 μgCd(Ⅱ )·cm- 2 。镉含量在 0～ 1 5 μg·2 5mL- 1 范围内服从比尔定律。回收率为 96%～ 1 0 5 %。方法操作简便 ,不需要萃取分离 ,可在水相中直接测定 ,故大大简化了操作手续。用本法测定了聚合硫酸铁絮凝剂中的痕量镉 ,得满意效果
In this paper, a new spectrophotometric method for the determination of trace amounts of cadmium in polymeric ferric sulfate flocculants has been studied and the mechanism of color reaction has been discussed. This method is the determination of trace amounts of cadmium in polyferric sulfate flocculant by spectrophotometry. Color developers are rhodamine B and potassium iodide. Surfactant is polyvinyl alcohol (PVA). Photometric color reaction sensitivity, the maximum absorption wavelength of 60 7nm. The apparent molar absorptivity is 4 99 × 105 L · mol-1 · cm-1. Sensitivity of Sander was 2 2 5 × 10 4 - 4 μg Cd (Ⅱ) · cm -2. Beer’s law was obeyed in the range of 0-1 5 μg · 25 mL-1. The recovery rate was 96% ~ 105%. The method is simple, does not require extraction and separation, can be measured directly in the water phase, it greatly simplifies the operating procedures. This method was used to determine the amount of trace amounts of cadmium in the coagulant of ferric sulphate to obtain satisfactory results