聚酰胺分离富集催化动力学电位法测定痕量钯

Catalytic Kinetic Potentiometric Determination of Trace Palladium after Separation and Enrichment by Polyamide

研究了一种以痕量Pd2+为催化剂,邻二氮杂菲作活化剂,并基于铁氰化钾与EDTA之间的配位反应为指示反应的催化动力学电位法.该法基于用氰电极测定反应中释放出来的氰化物,测定钯的线性范围为5.0×10-100～5.0×10-6mol/L,检出限为1.32×10-11mol/L.采用聚酰胺分离富集可以除去干扰离子的影响.该法用于样品中痕量钯的测定,结果满意.

A new catalytic potentiometric method has been developed for the determination of palladium with the ligand exchange reaction between potassium ferricyanide and EDTA used as indicatory reaction and orthophenanthroline used as activator. The cyanide released from the catalytic reaction is determined by cyanide electrod, and its amounts is proportional to the concentration of Pd（ Ⅱ） over a range of 5. 0×10^-10～5. 0×10^-6 mol/L. The detection limit is 1. 32 ×10^-11 g/mL for Pd. The method has higher selectivity and more than twenty doexisting ions do not interfere with the determination. Palladium can be separated from main interfering ions such as Pt^4＋ ,Ag^＋ , Hg^2＋ ,Pd^2＋ ,T1^＋ and Te^4＋ by polyamide. The method has been applied to the determination of trace palladium with satisfactory results.