一种聚氯乙烯钙电极的研制

Preparation and study of a PVC calcium—sensitive electrode

一、前言 1967年Ross首先以二癸基磷酸钙溶于苯基膦酸二辛酯的溶液为液体离子交换剂,制成液态膜钙电极。1970年Moody等人用与上面相同的离子交换剂制成P.V.C(聚氯乙烯)膜钙电极。其电阻为25MΩ,响应时间为6秒。72年他们对这种电极又进行了深入的研究,电极的性能有所改进。但响应时间却增长至三分钟。我们找到了另外一种国产溶剂——甲基膦酸二(1—甲)庚脂,用自己合成的二癸基磷酸钙为电活性物质,试制成一种P.V.C钙电极,其电阻约为0.02MΩ,响应时间为二秒。

A lower resistance, rapid response, calcium-sensitive electrode has been made by incorporating calcium salt of di-n-decylphosphoric acid and di (l-methylheptyl) methylphosphonate in to a poly (vinyl chloride) matrix membrane. The electrode nearly follows Nernstian behaviour between 10° and 65℃. Selectivities have been obtained by Several methods for Mg^(++), Ba^(++), Zn^(++), Sr^(++), Na^+ and K^+. The results of the determination of calcium in tap water with the PVC electrode and by a standard EDTA method are satisfactory.