Die bestimmung des gesamtschwefels in vulkanisierten gummimischungen

A method is described in which by means of a resin ion-exchanger the interference of foreign cations, particularly iron and chromium, can be prevented in the determination of total sulphur in vulcanized rubbers. The procedure allows the use of rapid volumetric methods for determining sulphate even when analyzing mixtures containing iron oxide or chromium oxide pigments. Here, the sulphate is precipitated with benzidine and determined by titration with sodium hydroxide solution. The method is quicker and more certain than the usual barium sulphate gravimetric procedure.