CATALYTIC DETERMINATION OF ULTRATRACE AMOUNTS OF RUTHENIUM WITH OSCILLOPOLAROGRAPHY MONITORING

The single sweep oscillopolarographic behaviour of Rhodamine B in sulp huric acid medium was investigated. A novel, sensitive and selective c atalytic method with oscillopolarography monitoring for the determinat ion of ultratrace amounts of ruthenium was described, based on the cat alytic effect of Ru(III) on the slow redox reaction occuring between R hodamine B and potassium periodate in sulphuric acid medium at 25-degr ees-C. Single sweep oscillopolarography is used to monitor the changes in concentration of Rhodamine B by means of the second derivative wav e at -0.55 V vs. SCE. The determination range from 8.2X10(-10) to 2.5X 10(-8) M Ru was obtained by the initial rate procedure. Influence of 3 0 foreign ions was considered. Ru in ore samples was analysed by this method, with satisfactory results.