离子缔合体系分光光度法测定化工废水中的镉  

Spectrophotometric determination of cadmium in chemical industrial wastewater with ion-association system

作　　者：李人宇[1,2] 李咏梅[2,3] 卢洋[1] 黄勇波[1] 

机构地区：[1]连云港师范高等专科学校,江苏连云港222006 [2]淮海工学院江苏省海洋资源开发研究院,江苏连云港222005 [3]淮海工学院化学工程学院,江苏连云港222005

出　　处：《工业水处理》2010年第9期69-72,共4页Industrial Water Treatment

基　　金：江苏省海洋资源开发研究院科技开放基金项目(JSIMR09C08);连云港市科技项目(SH0816);2009年江苏省高等学校大学生实践创新训练计划项目(414)

摘　　要：在pH=5.7的NaAc-HAc缓冲溶液中,Cd2+与邻菲啰啉(phen)和刚果红(CR)反应生成稳定的离子缔合物[Cd(phen)3](CR)2,体系吸光度明显增强,建立了分光光度法测定痕量镉的新方法。试验了酸度、试剂用量、表面活性剂、反应温度和时间的影响,确定了最佳反应条件。最大吸收峰位于561 nm。镉质量浓度在0～2.5 mg/L范围内符合比尔定律,表观摩尔吸光系数为4.51×104 L/(mol·cm),检出限为19.6μg/L。采用巯基棉分离富集,测定化工废水中的镉,相对标准偏差为0.34%～0.94%(n=5),回收率为97.3%～102.5%。A new method for the determination of trace cadmium by spectrophotometry has been developed. The method is based on the reaction of Cd^2＋ with phen and congo red （CR） to form a stable ion-association complex [Cd （phen）3] （CR）2 in NaAc-HAc buffer solution at pH=5.7, which results in great enhancement of absorbance with the maximum absorption peak at 561 nm. The effects of acidity, reagent dosage, surfactant, reaction temperature and time are examined, and the optimum reaction conditions for the determination of trace Cadmium are confirmed. When the cadmium concentration is in the range of 0-2.5 mg/L, it accords with Beer＇s law. The molar absorption coefficient is 4.51 ×10^4 L/（mol. cm） and its detection limit is 19.6μg/L. After separation and enrichment with sulfhydryl cotton, the cadmium in chemical industrial wastewater is determinated. RSDs are 0.34%- 0.94%（n=5）, and recovery rates are 97.3%-102.5%.

关 键 词：分光光度法 镉 离子缔合物 邻菲啰啉 刚果红 

分 类 号：O657.32[理学—分析化学] X832[理学—化学]