杂多酸吸附波示波极谱法测定磷

Oscillopolarographic Determination of Phosphorus With Adsorptive Wave of Molybdophosphoric Acid

在ＰＨ＝１的ＨＣｌ和２５ｍｇ／ｍｌ抗坏血酸存在的溶液中，正磷酸盐与钼酸铵形成具有极谱活性的磷钼杂多酸。该杂多酸在ＮＨ３－ＮＨ４Ｃｌ（ＰＨ＝９．９）底液中有一灵敏吸附波，其峰电位为－１．１２（ＶＳ．ＳＣＥ）。导数波高与波浓度在５×１０－８～４×１０－５ｍｏｌ／Ｌ范围内呈良好的线性关系。检测下限达２×１０－８ｍｏｌ／Ｌ。并利用形成杂多酸速度的差异消除大量硅的干扰。对吸附波的性质作了初步的研究。

In a solution of HCl at PH1. 1 and ascorbic acid, osthophosphate andammoniummolybdate produces molybdophosphoric acid with active polarogram. Molybdophosphoricacid produces a very sensitive adsorptive wave in the supporting electrolyte of NH3-NH4Clat PH9. 9. The peak potential appears at-1. 12V(Vs,SCE). The derivative wave height isproportional tl the concentration of phosphorus in the range of 5×10-8mol/L to 4 ×10-5mol/L and. the detection limit is 2 ×10-8mol/L.