Abstract: Steel (500 to 2000 µg) was dissolved in H2SO4 - H3PO4 (35 ml), followed by oxidation with HNO3 (2 ml) and boiling to expel nitrous acid fumes; any carbides remaining were evaporated. To the cooled solution water (50 ml) and concentrated HNO3 (5 ml) were added. The solution was boiled for 2 min and 0.5% KIO3 (10 ml) was added followed by boiling for a further 4 min. The solution was then cooled and transferred to a 100 mL volumetric flask and made up to volume with water. The peak height was measured using the flow injection system. Sample was injected into a carrier stream of phosphate buffer (pH 6) which was merged with aqueous NH4F solution (0.70 mL min-1), mixed with aqueous 0.10% benzyltributylammonium chloride solution (0.67 mL min-1) in a coil (25 cm x 0.5 mm). The aqueous phase was mixed with CHCl3 and passed through an extraction coil (150 cm x 0.5 mm) followed by a phase separator. The organic phase was used for the spectrophotometric determination of the Mn(VII) complex at 548 nm. The calibration graph was rectilinear from 0 to 25 µg mL-1 and the detection limit was 0.91 g mL-1 of Mn, (for 250 µL injections). The method was also applied to the determination of Mn in copper - nickel alloy. A flow injection manifold has been developed for the spectrophotometric determination of manganese(VII) at 548 nm after extraction into chloroform of the ion-associated, benzyltributylammonium permanganate. The carrier stream was a pH 6 buffer containing 10%(w/v) ammonium fluoride and the reagent stream was 0.10%(w/v) benzyltributylammonium chloride. The injection rate was 20 h-1. The calibration graph is linear up to 25 µg mL-1 and the detection limit (3 x baseline noise) is 0.91 µg mL-1 Mn(VII), based on 250 µL injection volumes The system has been applied to the determination of manganese in steels and a cupro-nickel alloy.