溴酚蓝-过氧化氢催化动力学体系光度法测定痕量铜.pdf

2012年4月
岩矿測试
Vol 31. No.2
April 2012
ROCK AND MINERAL ANALYSIS
291~294
文章编号:0254-5357(2012)02-0291-04
溴酚蓝-过氧化氢催化动力学体系光度法测定痕量铜
谢建鹰,陈园园,阳海华
(上饶师范学院化学化工学院,江西上饶334001)
摘要:在pH=4.5的HAc-NaAc缓冲溶液介质中,以溴化十六烷基吡啶(CPB)为増敏剂,痕量Cu(Ⅱ)能催
化过氧化氢氧化溴酚蓝使之褪色,据此用于测定痕量铜。讨论了介质、试剂用量、反应温度、反应时间、表面
活性剂及其共存离子的影响,确定测定波长为593nm及最佳实验条件,测得反应表观活化能为90.3
kJ/mol。在优化条件下,方法检出限为0.646ng/mL,Cu(Ⅱ)的质量浓度在0~0.064g/mL范内与
lg(Ao/A)呈良好的线性关系,大多数常见元素不干扰测定。方法用于煤样中痕量铜的分析,5次測定的相对
标准偏差小于3.1%,加标回收率在92.7%~107.0%,测定结果与原子吸收光谱法的结果一致。
关键词:痕量铜;催化光度法;澳酚蓝;过氧化氩
中图分类号:0614.121;0657.32
文献标识码
A Kinetic Spectrophotometric Method for the Determination of
Trace Copper with Bromophenol Blue and Hydrogen Peroxide
XIE Jian-ying, CHEN Yuan-yuan, YANG Hai-hua
College of Chemistry and Chemical Engineering, Shangrao Normal College
Shangrao 334001, China
Absrtact A new catalytic kinetic spectrophotometry for the determination of copper has been established. The
method is based on the catalytic effect of trace Cu (I on the oxidizing discoloring reaction of bromophenol blue
with hydrogen peroxide using cetyl pyridinium bromide as a sensitizer in HAC-NAAC buffer solution at PH=4. 5
Major factors such as acidity, reagent dosage, reaction temperature, reaction time, and the influence of surfactant
and coexisting irons were studied. The detection wavelength was selected as 593 nm with optimal conditions. The
apparent activation energy of the catalytic reaction was 90.3 KJ/mol. Under the optimal conditions, the detecti
limit of this method was 6. 46 x"g/ml. In the content range of 0 to 0.064 wg/ml, there was a good linear
relationship between the concentration of Cu( I and lg(A/A). This method was simple, rapid, and highly
selective. There were no interferences from the most common coexisting ions during determination. The proposed
method was applied to the determination of trace copper in coal. The relative standard deviation was less than
3. 1%o (n=5), and the recoveries of standard addition were 92.7%-107.0%. The determination reults were
consistent with those obtained by atomic absorption spectromet
Key words: trace copper; catalytic spectrophotometry; bromophenol blue; hydrogen peroxide
收稿日期:2011-09-08;接受日期;2012-02-20
基金项目:教育部第四批高等学校特色专业建设点资助项目(TS1524);江西省教育厅科技项目(GJ1606
作者简介:谢建鷹,教授,主要研究方向为痕量分析。E-mail:xjy8359@sina.com