SIMULTANEOUS DETERMINATION OF BERYLLIUM AND ALUMINUM IN MIXTURES USING DERIVATIVE SPECTROPHOTOMETRY

The spectrophotometric determination of beryllium and aluminium with 5 ,8-dihydroxy-1,4-naphthoquinone in the presence of a non-ionic surfact ant is reported. Absorption maxima, molar absorptivity and Sandell's S ensitivity of 1:2 (M:L) beryllium and aluminium complexes are, 585 nm and 598 nn, 1.63 x 10(4) l.mole-1.cm-1 and 2.04 x 10(4) l.mole-1.cm-1, and 0.55 ng/cm2 and 1.32 ng/cm2 respectively. Beer's law is obeyed be tween 7.20-3.96 x 10(2) ng/ml beryllium and 1.08 x 10(1)-1.08 x 10(3) ng/ml aluminium. A method for simultaneous determination of beryllium and aluminium in their mixture using derivative spectra is described. The range 3.6 x 10(1)-3.6 x 10(2) ng/ml beryllium could be determined in the presence of 1.08 x 10(2)-1.08 x 10(3) ng/ml aluminium, and vice versa.