天然水中痕量磷酸根、亚砷酸根和砷酸根的浮膜分光光度法测定

本文研究了孔雀绿与磷（砷）酸钼的离子对膜的形成条件。并依此与共存元素分离，进行痕量磷酸根、亚砷酸根和砷酸根的浮膜分光光度法测定。选用硫酸为介质，考察了25种共存离子对测定的影响。拟定了天然水中痕量磷酸根、亚砷酸根和砷酸根的分析方法．操作简便，结果令人满意。

Determination of phosphate,arsenate and arsenite in natural water by flotation membrane-spectro-photometry using malachite green as an ion-pair reagent

A sensitive and accurate method is described for the determination of phosphate,Arsenate and Arsenite in natural water using malachite green as an ion-pair reagent. The formation of ion-pair membrane of malachite green with-molydophosphate (molydoarsenic) and the spectrophotometric determination of PO3-4,AsO3-4 and AsO3-3 are investigeted. The methanol is added to dissolve the floated ion-pair. The apparent molar absorptivity is 2.95×105L. mol-1·cm-1 for PO3-4 and 1. 8×105L. mol-1·cm-1 for AsO3-4. Beer's law is obeyed in the range from 0 to 8 μg/25 ml PO3-4 and from 0 to 6 μg/25 ml AsO3-4. In a medium of H2SO4,the effect of 25 ions has been studied and it has been found that many ions do not interfere. The method is simple and the analytical results are satisfactory.