Simultaneous Determination Of Aluminium (Iii) And Gallium (Iii) By Second Order Derivative Spectrophotometry Using 2-Hydroxy-1-Naphthaldehyde-P-Hydroxy Benzoichydrazone

A highly sensitive and selective second order derivative spectrophotometric method is proposed for the simultaneous determination of aluminium and gallium. Al(III) and Ga(III) react with 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) at pH 6.0 forming lemon yellow coloured and yellow coloured solutions with max at 445 nm and 455nm respectively. Both the metal ions were simultaneous determined by measuring the second derivative amplitudes at 476.5 nm and 449.5 nm (zero cross method) against the reagent blank and plotting against the amount of the corresponding metal ion. Beer’s law was obeyed in the range 0.013-0.256 μg mL-1 and 0.017-1.324 μg mL-1 for Al(III) and Ga(III) respectively. No interference from associated anions and cations was observed. The method was applied for the determination of Al(III) and Ga(III) in standard reference materials and biological samples.