摘要
在ｐＨ１０．３的Ｎａ２Ｂ４Ｏ７ＮａＯＨ介质中，Ｍｇ２＋与４，５－二溴苯基荧光酮（Ｂｒ－ＰＦ）形成络合物，于－０．９５Ｖ（ｖｓ．ＳＣＥ）出现一灵敏的阴极波。Ｍｇ２＋的质量浓度在８．２～５８μｇ／Ｌ时与峰电流呈线性关系，检出限为２．１μｇ／Ｌ。研究了极谱电流的性质、反应机理及电极过程等，确认获得的极谱波为络合物吸附波，络合物的组成为ｎＭｇ∶ｎＢｒ－ＰＦ＝１∶１，条件稳定常数２．２×１０６，电极过程不可逆。方法应用于铝合金、球墨铸铁标样中镁的测定，结果与标准值相符。５次测定的ＲＳＤ＜３．０２％
In the midium of Na\-2B\-4O\-7NaOH (pH=10.3), magnesium forms a complex withdibromo￣phenylfluorone (BrPF) and produces a distinct polarographic wave at -0.95 V (vs. S C E). The linear relationship exists between the concentration of Mg2+ and peak current in the range of 8.258 g/L with detection limit of 2.1 g/L. The characteristics of the polarographic current, reaction mechanism and electrode process have been studied. It has been proved that the polarographic wave is an adsorptive wave of the complex and the composition ratio of magnesium to BrPF is 11 with conditional stability constant of 2.2106. The electrode process is irreversible. The method has been applied to the determination of magnesium in aluminium alloy and nodular cast iron samples. The results are in agreement with the certified values with precision of <3.02% RSD (n=5).\=\=
出处
《岩矿测试》
CAS
CSCD
北大核心
1999年第3期225-228,共4页
Rock and Mineral Analysis
基金
云南省教委基金
关键词
镁
二溴苯基荧光酮
络合物吸附波
magnesium
dibromophenylfluorone
complex
adsorptive wave
