A critical study of safranine O as a spectrophotometric reagent: a rapid method for the determination of trace amounts of antimony in steel

Abstract

The behaviour of Safranine O (Basic red 2, C.I. 50240) in aqueous solutions has been investigated and its suitability as a spectrophotometric reagent is evaluated and discussed. A rapid method for the determination of antimony as a hexachloroantimonate(V) ion-association complex with Safranine O is described. This complex is extracted into benzene and is determined spectrophotometrically. The method is as sensitive and reproducible as the Rhodamine B method but it has the advantage that the determination can be carried out directly on solutions of steel without prior separation. Good agreement was found with standardised antimony values for five British Chemical Standards' steels.