摘要
使用电感耦合等离子体原子发射光谱法(ICP-AES)直接测定再生锌中铅和镉时,锌和铁等共存元素会对测定产生干扰。当待测液中锌含量分别大于铅和镉含量的20倍时,直接测定铅和镉结果的相对误差均大于5%,而再生锌中锌相对铅和镉的含量远高于此倍数。研究表明,在I-存在下,再生锌样品中的Pb^2+和Cd^2+分别形成具有8-羟基喹啉螯合物结构的PbI2^-4和CdI2^-4络阴离子,此时Zn^2+、Fe2+和Ca^2+等阳离子不形成碘络阴离子。以强碱性阴离子交换纤维(SBAEF)萃取溶液中的PbI24-和CdI2^-4,SBAEF能特异性吸附8-羟基喹啉螯合物PbI2^-4和CdI2^-4,使铅、镉与锌、铁、钙等干扰元素分离,再用一定浓度的EDTA溶液将PbI24-和CdI2^-4同时洗脱,然后使用ICP-AES测定,从而建立了再生锌中铅和镉的测定方法。方法有效地消除了锌、铁等共存元素对测定的干扰,测定范围为:0.10%≤wPb≤10.00%;0.050%≤wCd≤5.00%。方法应用于实际再生锌样品中铅和镉的测定,结果的相对标准偏差(RSD,n=5)为0.89%~1.7%,回收率为99%~101%。采用实验方法测定与再生锌成分相似的锌精矿标准样品中铅和镉,测定结果与认定值相吻合;采用实验方法测定再生锌模拟液,铅和镉的回收率为97%~104%。
During the direct determination of lead and cadmium in regenerated zinc by inductively coupled plasma atomic emission spectrometry(ICP-AES),the coexisting elements such as zinc and iron would cause interference.When the content of zinc in testing solution was 20 times higher than that of lead and cadmium,the relative error of both lead and cadmium by direct determination was higher than 5%.In fact,the content of zinc in regenerated zinc was much higher than this fold compared to lead and cadmium.In presence of I-,it was found that Pb2+and Cd2+in regenerated zinc sample could form PbI24-and CdI24-complex anions with the structure of 8-hydroxyquinoline chelate.Meanwhile,the cations such as Zn2+,Fe2+and Ca2+would not react with I-to form complex anions.PbI24-and CdI24-in solution were extracted with strongly basic anion exchange fiber(SBAEF).SBAEF could specifically absorb 8-hydroxyquinoline chelates(PbI24-and CdI24-),realizing the separation of lead and cadmium from interference elements including zinc,iron and calcium.Then PbI24-and CdI24-were simultaneously eluted with EDTA solution for the determination by ICP-AES.Thus the determination method of lead and cadmium in regenerated zinc was established.The proposed method could effectively eliminate the interference of coexisting elements such as zinc and iron.The determination range was 0.10%≤wPb≤10.00% and 0.050%≤wCd≤5.00%.The proposed method was applied to the determination of lead and cadmium in actual samples of regenerated zinc.The relative standard deviations(RSD,n=5)of determination methods were between 0.89% and1.7%,and the recoveries were between 99%and 101%.The contents of lead and cadmium in certified reference material of zinc concentrate with similar composition to regenerated zinc were determined according to the experimental method.The found results were consistent with the certified values.The simulated solution of regenerated zinc was determined according to the experimental method.The recoveries of lead and cadmium were between 97% and 104%.
作者
郑向明
叶玲玲
魏雅娟
江荆
吴雪英
吴魏成
ZHENG Xiang-ming;YE Ling-ling;WEI Ya-juan;JIANG Jing;WU Xue-ying;WU Wei-cheng(China Certification & Inspection Group Guangxi Co., Ltd., Fangchenggang 538001,China;Guangxi Zhongjian Testing Technology Service Co., Ltd., Fangchenggang 538001,China)
出处
《冶金分析》
CAS
北大核心
2019年第8期76-84,共9页
Metallurgical Analysis
