| Study on the Determination of Trace Ni（Ⅱ） by the Catalytic Kinetic Spectrophotometric Method |
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| 作者单位： | College of Chemistry and Chemical Engineering, Key Laboratory of Marine Chemistry Theory and Technology,the Ministry of Education, Ocean University of China, Qingdao 266003, P. R. China |
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| 摘 要： | A new kinetic spectrophotometric method has been developed for the determination of trace Ni (II) in natural water.The method is based on the catalytic effect of Ni (II) on the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 in acid medium.The concentration of nickel (II) can be determined spectrophotometrically by measuring the decrease of absorbance of RAWL at λ= 626 nm using the fix-time method.The influencing factors are investigated by the orthogonal experimental design.The obtained optimum analytical conditions are:pH=2.00,c RAWL=5.00×10-5 mol L-1,cKIO 4= 2.00×10-5 mol L-1,the reaction time t=10 min and the temperature T=25℃..Under the optimum conditions,the developed method allows the measurement of Ni (II) in a range of 0-40.0 ng mL-1.The standard deviation of eleven independent measurements of blank reaction is S=3.08×10-3 and the limit of detection is 2.20 ng mL-1.The relative standard deviations (RSDs) in six replicate determinations of 5 ng mL-1 and 8 ng mL-1 Ni (II) are 2.87% and 1.11%,respectively.Moreover,the experiments show few cations and anions can interfere with the measurement of Ni (II).The recovery efficiencies of this method are in a range of 97.0%-102.5% in freshwater samples.But there is a decreasing effect,which is about 0.2 times the added Ni (II) in seawater medium.After reasonable calibration this processing method is used for the determination of Ni (II) in seawater samples successfully.The results show this developed method has high accuracy and precision,high sensitivity,large range of linearity and high speed.The method can,therefore,be employed at room temperature.
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| 关 键 词： | 光度法测定 催化动力学 微量镍 正交实验设计 相对标准偏差 镍（Ⅱ） 分光光度计 测量范围 |
| 收稿时间： | 8 March 2009 |
Study on the determination of trace Ni (II) by the catalytic kinetic spectrophotometric method |
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| Authors: | Hongwei Ji Hengxia Cao Huizhen Xin Shuang Li |
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| Institution: | College of Chemistry and Chemical Engineering, Key Laboratory of Marine Chemistry Theory and Technology,the Ministry of Education, Ocean University of China, Qingdao 266003, P. R. China |
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| Abstract: | A new kinetic spectrophotometric method has been developed for the determination of trace Ni (II) in natural water. The method
is based on the catalytic effect of Ni (II) on the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 in acid medium. The concentration of nickel (II) can be determined spectrophotometrically by measuring the decrease of absorbance
of RAWL at λ = 626 nm using the fix-time method. The influencing factors are investigated by the orthogonal experimental design. The obtained
optimum analytical conditions are: pH = 2.00, c
RAWL = 5.00×10?5 mol L?1, c
KIO
4 = 2.00×10?5 mol L ?1, the reaction time t = 10 min and the temperature T = 25°C. Under the optimum conditions, the developed method allows the measurement of Ni (II) in a range of 0–40.0 ng mL?1. The standard deviation of eleven independent measurements of blank reaction is S = 3.08×10?3 and the limit of detection is 2.20 ng mL?1. The relative standard deviations (RSDs) in six replicate determinations of 5 ng mL?1 and 8 ng mL?1 Ni (II) are 2.87% and 1.11%, respectively. Moreover, the experiments show few cations and anions can interfere with the measurement
of Ni (II). The recovery efficiencies of this method are in a range of 97.0%–102.5% in freshwater samples. But there is a
decreasing effect, which is about 0.2 times the added Ni (II) in seawater medium. After reasonable calibration this processing
method is used for the determination of Ni (II) in seawater samples successfully. The results show this developed method has
high accuracy and precision, high sensitivity, large range of linearity and high speed. The method can, therefore, be employed
at room temperature. |
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| Keywords: | kinetic-spectrophotometry catalytic effect weak acid brilliant blue dye (R AWL) potassium periodate de- creasing effect |
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