Direct Spectrophotometric determination of Aluminum (III) using 5-Bromo-2-hydroxy-3-methoxybenzaldehyde-P- hydroxybenzoic hydrazone

Highly sensitive and selective direct spectrophotometric method is proposed for the determination of aluminium in various real samples. 5-Bromo-2-hydroxy-3-methoxybenzaldehyde-phydroxybenzoic hydrazone reacts with Al(III) forming yellow coloured soluble complex in aqueous dimethyl formamide which has a λmax at 390 nm in the pH range 3.0-7.0. The system obeyed Beer’s law in the range 0.053 – 0.755 μg mL-1 of Al(III). The molar absorptivity is 2.66 x 10 4 L mol-1 cm-1 and The Sandell’s sensitivity is 0.00104 μg/c m 2 . The standard deviation of the method for ten determinations of 0.42281 μg/m l o f A l ( I I I ) i s 0 . 0 0 7 5 . T h e correlation coefficient (γ) of the calibration equation of the experimental data is 0 . 9 9 9 9 . Studies on effect of diverse ions showed almost all the anions, except F and a majority of the cations do not interfere in more than 50 fold excess. The interference from Ni(II), Fe(III), Cu(II) and Ti(IV) was eliminated by using suitable masking agents. The direct method was applied for the determination of aluminium in silicate minerals, industrial sludges, soil samples plant extracts, hair, tea and water samples.