2,2 ',3,4-Tetrahydroxy-3 '-sulpho-5 '-nitroazobenzene for spectrophotometric determination of aluminium in pharmaceutical suspensions and granite

Abstract

A selective and sensitive new spectrophotometric method has been developed for the determination of aluminium.2,2',3,4-Tetrahydroxyy-3'-sulpho-5'-nitroaobenzene (tetrahydroxyazon SN) formed an orange chelate with aluminium at pH 4. Molar absorptivity of the complex in 1:2 is 5.46 x 10(4) l mol(-1) cm(-1) at 479 nm. The method obeys Beer's law in the range of 0.005-1.079 mu g ml(-1). The determination of aluminium is not interfered with by earth alkaline, alkaline elements, rare earth elements, halides, phosphates, sulphates, urea, ascorbic acid, Sn2+, Sr2+, Cr3+, Cd2+, Hg2+, 'Mn2+. The proposed method is rapid and simple, and it has been succes or successfully applied to the determination of aluminium in certified pharmaceutieal suspension and granite