Spectrophotometric determination of total iron with 2,2-bipyridyl

Spectrophotometric determination of total iron with 2,2 -bipyridyl 

In order to be able to determine the total iron content of a water spectro-photometrically with 2,2 -bipyridyl it is necessary to reduce the trivalent iron to iron (II) ions. Ascorbic acid is used as a reducing agent. 

If undissolved or colloidal iron is also to be determined, the water is 

Sodium acetate, CH3COONa 3 H2O, reagent purity Iron (III) reference solution I  

Dissolve 0.1 30 g of reagent-purity iron (III) oxide in about 25 ml of hydrochloric acid (1.19 g/ml) at about 60 C, dilute the solution with water, transfer to a 1-litre measuring flask and make up to the mark at 20 C. 1 ml of this solution contains 0.1 mg iron (III) ions. 

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