铍试剂Ⅲ/钙色素双偶氮染料-示波计时电位法快速测定天然水中不同形态铝  

Determination of Aluminum Speciation in Natural Waters by Alternating Current Oscillochronopotentiometry Using Two Di-O-hydroxyzao, Berryllon Ⅲ and Calcion

作　　者：干宁[1] 毕树平[1] 雷建平[1] 

机构地区：[1]南京大学化学系,污染控制与资源化国家重点实验室,南京210093

出　　处：《分析化学》2003年第4期420-424,共5页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金 (No .2 0 0 75 0 11);教育部优秀青年教师奖励计划;重点实验室高级访问学者基金;南京大学分析测试基金资助课题

摘　　要：采用铍试剂Ⅲ (简称BER)和钙色素 (简称CAL)双偶氮染料 示波计时电位法快速测定天然水中不同形态铝。实验条件和结果如下 :在pH 5 .0NH4Ac HAc缓冲溶液中 ,BER在dE dt E示波图上出现一个切口 ,Ep1 =-0 .3 5V。加入铝后出现一新切口 ,Ep2 =-0 .70V ,该切口深度与加入铝量在 1 .0× 1 0 - 6 ～ 2 .0× 1 0 - 5mol L浓度范围内呈线性关系 ;检出限为 5 .0× 1 0 - 7mol L ;在 5 .0× 1 0 - 6 mol LAl时相对标准偏差为 5 5 % (n=1 0 )。在pH 8.0NH4Ac NH3·H2 O缓冲溶液中 ,CAL在示波图上出现一个切口 ,EP′1 =-0 .60V。加入铝后出现一新切口 ,EP′2 =-0 .75V ,该切口深度与加入铝量在 1 .0×1 0 - 6 ～ 1 .0× 1 0 - 5mol L浓度范围内呈线性关系 ,检出限为 5 .0× 1 0 - 7mol L ;在 2 .0× 1 0 - 6 mol LAl时 ,相对标准偏差为 5 .5 % (n =1 0 )。分别采用两种试剂在弱酸性和弱碱性条件下测定了天然水样中的铝浓度 ,发现在弱酸性下测定的是无机单核铝 ,而在弱碱性下则是总单核铝 ,据此可以实现对 5种铝形态的区分。测定了实际天然水样 ,与Driscoll方法进行了对照 。A simple and reliable electroanalytical method for the fast determination of different species of aluminum(total Al T, acid soluble Al r, monomeric Al a, inorganic monomeric Al i, organic monomeric Al o) in natural waters by a.c.oscillochronopotentiometry using berryllon Ⅲ and calcion is described. In alkaline buffer solution (pH 8 0), calcion was used to determine the total monomeric aluminum, and in acidified buffer solution (pH 5.0), berryllon Ⅲ was used to detect the inorganic monomeric aluminum. This method was successfully applied to the analysis of different species of Al in real natural water samples. The results were found in good agreement with those obtained by Driscoll′s method. Chemical equilibrium principle was applied to prove the theoretical foundation of the proposed method for determining different species of Al in natural waters.

关 键 词：铍试剂Ⅲ 钙色素 双偶氮染料 示波计时电位法 测定 天然水 形态分析 铝 环境水样 毒性 

分 类 号：O657.1[理学—分析化学]