学术
摘 要:
在pH10.0氨水-氯化铵缓冲溶液中,镍（Ⅱ）对溴酸钾氧化甲基紫的褪色反应具有抑制性作用,阳离子表面活性剂苄基三乙基氯化铵对此体系有强烈增敏作用,据此建立了阻抑动力学光度法测定痕量镍（Ⅱ）的新方法。本法测定Ni的线性范围为0～100μg/L,检测限为8.4×10^-7g/L。该阻抑反应对甲基紫为零级反应,对溴酸钾和镍为一级反应;阻抑活化能为116.14 kJ/mol,非阻抑活化学能为78.14 kJ/mol。大部分共存离子对测定没有干扰,Cd^2＋,Cu^2＋,Co^2＋对测定有严重干扰,可预先用N530煤油萃取分离除去。方法用于铝合金和环境水样中痕量镍的测定,结果良好。[著者文摘]
文章出处:
《冶金分析》-2008年28卷2期 -40-43页
分 类 号:
文献标识码:
A
文章编号:
1000-7571（2008）02-0040-04
Inhibitory kinetic spectrophotometric determination of trace nickel in Ni（Ⅱ）-KBrO3-methyl violet system with benzyl triethylammonium chloride as enhanced sensitivity agent
WANG Xiao-ju ,GAO Ye, SUN Ling-chen,HU Hai-long （Department of Chemistry, Changchun Normal College,Changchun 130032,China）
Abstract:
A new inhibitory catalytic kinetic spectrophotometric method for the determination of trace amounts of Ni（Ⅱ） has been developed. The method is based on the inhibitory catalytic effect of Ni（Ⅱ） on oxidation of methyl violet by potassium bromate in the solution of NH3·H2O-NH4Cl（pH 10. 0） and in the presence of cationic surfactant of benzyl triethyl ammonium chloride （BTEAC） as an enhanced sensitivity agent. The effects of the pH and the coexistence ions on the determination were discussed. Under the optimum experimental conditions,the linear range was 0-100 μg/L and the detection limit was 8.4×10^-7 g/L. The most common ions did not interfere. The interfering effects of Cd^2＋ ,Cu^2＋ and Co^2＋ could be effectively eliminated by extraction with N530. The inhibition catalytic reaction was zeroth-order reaction for methyl violet and first order one for both Ni（Ⅱ） and KBrO3. The average of apparent activation energy for inhibition catalytic reaction and non-inhibition catalytic reaction was found to be 116.14 kJ/mol and 78.14 kJ/mol,respectively. The method is used for the determination of Ni（Ⅱ） in water and cast aluminium alloy with saisfactory results.[著者文摘]
Key words:
inhibition; catalytic kinetic spectrophotometry; nickel; potassium bromate; methyl violet ; benzyl triethylammonium chloride
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