Triton X-100微乳液介质中锡催化KBrO_3氧化5-NO_2-PADAP褪色反应动力学光度法测定痕量锡  

Kinetic spectrophotometric determination of trace tin based on its catalytic effect on the oxidation of 5-NO_2-PADAP with KBrO_3 in Triton X-100 microemulsion medium

作　　者：周之荣[1] 王群[2] 章淑媛[2] 

机构地区：[1]广东药学院公共卫生学院,广东广州510240 [2]东华理工大学校医院,江西抚州344000

出　　处：《冶金分析》2010年第2期42-46,共5页Metallurgical Analysis

基　　金：广东省高等学校人才引进专项资金资助项目(粤财教[2009]109号);广东药学院科研基金资助项目(2007GGW03)

摘　　要：基于在弱酸性微乳液介质中,加热温度为80℃时,痕量锡（Ⅳ）催化KBrO3氧化2-（5-硝基-2-吡啶偶氮）-5-二乙氨基酚（5-NO2-PADAP）的褪色反应,建立了测定痕量锡（Ⅳ）的动力学光度法。于450 nm波长处测定5-NO2-PADAP褪色溶液的吸光度降低值ΔA,ΔA与锡的质量浓度在0.053-1.0μg/L范围呈线性关系,方法检出限为0.016μg/L。结合巯基葡聚糖凝胶分离富集,方法用于环境水样中痕量锡（Ⅳ）的测定,结果与AAS测定值相符,相对标准偏差为2.2%-3.8%,加标回收率在102%-104%间;方法用于地质样品中痕量锡（Ⅳ）的测定,结果与认定值相符。A catalytic spectrophotometry for the determination of trace Sn（Ⅳ） is established based on its catalytic effect on discoloring reaction of oxidation of 2-（5-nitro-2-pyridylazo）-5-diethylaminophenol（5-NO2-PADAP） with potassium bromate in weak acidic microemulsion medium at 80 ℃.The decrease in the absorbance at 450 nm for the catalytic reaction of 5-NO2-PADAP is measured.The described value（ΔA） of absorbence is linear with the concentration of Sn（Ⅳ） over range of 0.05-1.0 μg/L,and the detection limit of the method is 0.016 μg/L.By combining with sulphydryl dextrane gel（SDG） separation and enrichment,the method has been successfully applied to the determination of Sn（Ⅳ） in environmental water samples with the relative standard deviation of 2.2 %-3.8 % and the recovery of 102 %-104 %.The results are in good agreement with those by AAS method.The method has also been successfully applied to the determination of Sn（Ⅳ） in geological samples,whose results are consistent with the certified values.

关 键 词：动力学光度法 锡(Ⅳ) 2-(5-硝基-2-吡啶偶氮)-5-二乙氨基酚(5-NO2-PADAP) 微乳液 分离 富集 

分 类 号：O657.32[理学—分析化学]