溴酸钾氧化酸性铬蓝K催化光度法测定痕量锌  

Catalytic kinetic spectrophotometric method for determination of trace zinc based on oxidation effect of potassium bromate on acid chroms blue K

作　　者：莎仁[1] 

机构地区：[1]内蒙古师范大学化学与环境科学学院,内蒙古呼和浩特010022

出　　处：《冶金分析》2007年第5期65-67,共3页Metallurgical Analysis

基　　金：内蒙古自治区自然科学基金(200408020213)

摘　　要：研究了在弱酸性介质中,锌(Ⅱ)催化溴酸钾氧化酸性铬蓝K的褪色反应及其动力学条件,建立了催化动力学光度法测定痕量锌的新方法。结果表明,该催化褪色反应对酸性铬蓝K,KBrO_3,H^+均为零级反应,对Zn(Ⅱ)为一级反应,测得表观活化能Ea=107.1kJ/mol,锌量在(0.16～8.0)×10^(-8)g/mL呈线性关系,检出限为1.1×10^(-10)g/mL,在NH_4F存在下大多数常见离子无干扰。用于测定水样和农产品中的痕量锌,相对标准偏差为1.4%～3.9%,加标回收率为94.5%～103%。A new catalytic kinetic spectrophotometric method for the determination of trace zinc（Ⅱ） is developed,based on the catalytic effect of zinc（Ⅱ） on the discoloration reaction of potassium bromate with acid chroms blue K in a weak acid medium. The results indicated that for acid chroms blue K, KBrO3 and H^＋ the reaction is zero order but one order for zinc （Ⅱ）. The apparent activation energy is 107.1 kJ/mol. The linear range of （0. 16-8. 0） × 10^-8 g/mL and the detection limit of 1.1 × 10^-10 g/mL were obtained. Common ions did not interfere in the determination of zinced）. The method has been applied to the determination of trace zinc（Ⅱ） in water and agricultural products,giving the relative standard deviation of 1.4 %-3.9 % and the recovery rate of 94.5 %-103 %.

关 键 词：锌 酸性铬蓝K 催化动力学光度法 

分 类 号：O657.3[理学—分析化学]