Colorimetric determination of aluminum in soil extracts using haematoxylin

A method for the determination of small amounts of aluminum using haematoxylin has been developed for use with soil extracts. The effects of initial and final pH, time, variations in the amounts of haematoxylin and acetate buffer and interference of ions on colour development were studied. As compared with the standard aluminon method, this method is six times more sensitive. Moreover, aluminum in the soil extracts of complex forming reagents such as fluoride, oxalate, citrate or EDTA can be determined. The recovery of added aluminum in the fluoride extract of the soil was complete