A new application of atomic absorption spectrophotometry : Determination of phthalic acid by solvent extraction with neocuproine-copper(I) chelate

A new application of atomic absorption spectrophotometry is reported for the determination of phthalic acid. Phthalic acid is extracted as the ion-pair formed between bis(neocuproine)-copper(I) and the univalent anion of phthalic acid with MIBK; the copper concentration in the extract is then determined by atomic ab sorption in an air-acetylene flame at the 3247 Å copper line. Optimal conditions are described. The absorbance of the extract showed a linear relationship to the concentration of phthalic acid initially present in the aqueous solution over the range of 4·10^-6 to 4·10^-5M. The effect of some analogous aromatic carboxylic acids on the phthalate extraction and the composition of the extracted species were also investigated.