Abstract

This paper develops a method for determining Al2O3 in vegetable-aluminum and aluminum tanned leathers. The method is based on the property of Al3+ to form a red complex compound with aluminon at pH = 5, l = 520nm. The preparation of the sample involves: ashing the sample at 700°C, melting the ash with 1.5g Na2B4O7 at 950°C and dissolving the melt with a dilute solution of HNO3. The proposed method is used to determine the content of Al2O3 in vegetable-aluminum tanned pig and lamb leathers. The results have a very good reproducibility, with relative standard deviation, Sr = 0.5-1.3%. The absence of systematic errors in the proposed procedure has been demonstrated.