Sorption-photometric determination of osmium using silica chemically modified with thiourea derivatives

The conditions for the adsorption of osmium on silica chemically modified with thiourea derivatives from sulfuric and hydrochloric acid solutions and from the gas phase are studied. A procedure for sorption-photometric determination of osmium after its transformation to OsO4 is proposed. The analytical range is 10-1500 mu g of Os per 0.1 g of the sorbent. The relative standard deviation in determining more than 50 mu g of osmium is no more than 10%. The procedure was used for determining osmium in the slime of wet dust collection and in wash acid.