锡(Ⅱ)-1-苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5-络合物吸附波的研究

Study on Adsorptive Wave of Complex of Tin(Ⅱ) with 1 Phenyl 3 Methyl 4 Benzoyl 5 pyrazolone

在ｐＨ４．０的ＨＡｃ－ＮａＡｃ缓冲介质中，Ｓｎ（Ⅱ）与１－苯基－３－甲基－４－苯甲酰基－吡唑啉酮－５（ＰＭＢＰ）生成络合物，于－０．７４Ｖ（ｖｓ．ＳＣＥ）出现一灵敏的极谱峰。锡含量在４．２×１０－８ｍｏｌ／Ｌ～３．４×１０－６ｍｏｌ／Ｌ范围内与峰高呈线性关系，检出限为１．７×１０－８ｍｏｌ／Ｌ。用多种电化学方法研究了极谱波的性质及电极反应机理，证明该极谱波为络合吸附波，峰电流由中心离子Ｓｎ（Ⅱ）还原产生，络合物组成为Ｓｎ（Ⅱ）∶ＰＭＢＰ＝１∶１。试验了多种离子对峰电流的影响。方法已用于矿样中痕量锡的测定。

The adsorptive polarographic wave of the complex of tin(Ⅱ) wiht 1 phenyl 3 methyl 4 benzoyl 5 pyrazolone(PMBP) has been studied.Its peak potential is -0.74V( vs .SCE) in acetic acid sodium acetate buffer medium at pH 4.0.The peak height of the wave is linear with the concentration of Sn(Ⅱ) in the range of 4.2×10 -8 ～3 4×10 -6 mol/L,and the detection limit is 1.7×10 -8 mol/L.Several electrochemical methods have been used to study the properties of the wave and reaction mechanism.It is proved that the wave is an adsorptive one and the peak current is caused by the reduction of Sn(Ⅱ) in the complex.The molar ratio of Sn(Ⅱ) to PMBP in the complex is 1∶1.The effects of many ions on the peak current have been tested.The proposed method has been applied to the determination of trace tin in ore with relative error and relative standard deviation ( n =8) of 2.3% and 5.9%,respectively.