Flotation spectrophotometric determination of aluminium with alizarin.

ABSTRACT Aluminium was determined in a weakly alkaline medium by reaction with alizarin at trace level. Flotation of the complex was carried out with heptane, followed by dissolution in N, N-dimethylformamide (DMF) for subsequent spectrophotometric determination. The molar absorptivity was 2.92×105 mol− cm− at 518 run. Beer's law was obeyed in the range 5–80 μg/1 and the detection limit was 0.4μg/l. The reliability of the procedure was confirmed by determination of a sample of milk with Graphite Furnace Atomic Absorption Spectrophotometric method (GFAAS). The precision and accuracy of the method were both acceptable via F and tests at the 95% confidence level.