The use of ascorbic acid to eliminate interference from iron in the aluminon method for determining aluminium in plant and soil extracts

Abstract

The aluminon method of Hsu for the determination of aluminium in soil has been examined for interference from the presence of iron and copper. Only iron(III) interfered. The use of thioglycollic acid not only eliminated this interference but bleached the colour of the aluminon reagent and caused a reduction in sensitivity. Ascorbic acid, however, eliminated it without bleaching the colour of the reagent, the addition of 1 ml of a 0·50 per cent. solution of ascorbic acid suppressing the interference from up to 500 µg of iron(III). When 200 µg of copper were added to aluminium standards no interference occurred.