Fluorometric determination of aluminium with bissalicylidene-ethylenediamine in the presence of amino acid

• Published in: BUNSEKI KAGAKU Vol. 35; no. 5; pp. 487 - 493
• Main Authors: AOKI, Izuo, WATANABE, Kunihiro
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society for Analytical Chemistry 05.05.1986
• Subjects: aluminium-salicylidene amino acid complexes; bissalicylidene-ethylenediamine; fluorometric determination of aluminium in the presence of amino acid; glycine and α-alanine
• ISSN: 0525-1931
• DOI: 10.2116/bunsekikagaku.35.5_487

Complex formation of aluminium-Schiff bases and its application to the fluorometric determination of aluminium have been studied. Bissalicylidene-ethylenediamine(BSED) used in the presence of a large amount of amino acid was hydrolyzed in the aqueous solution to liberate salicylaldehyde, which reacted with aluminium-amino acid complex to form a mixed chelate compound. The compound was transformed into a Schiff base complex in a aqueous solution by standing for 10 min at 50°C. The aluminium-Schiff base complex obtained is stable for 120 min, and has a blue fluorescence. The effect of 6 kinds of amino acids was discussed for the fluorescence intensity, so that glycine and α-alanine were superior to others. Among the derivatives of BSED discussed, bis(5, 5'-dimethylsali-cylidene)ethylenediamine(DM-BSED) exhibited an excellent property on the sensitivity with an emission maximum at 465 nm and excitation maximum at 360 nm. The optimum pH's for the fluorescence intensity were pH 5.6 and 5.4 in the presence of glycine and α- alanine, respectively. One ml of 20% ammonium acetate solution was used as buffer solution. The optimum amount of DM-BSED added was 1 ml of 0.07% DMF solution for the 25 ml of total volume containing glycine(4%, 1 ml) or α-alanine(6%, 1 ml). The composition of aluminium complex is Al : Schiff base=1:1.The fluorescence quantum efficiency of the aluminium complex was 0.35. The range of aluminium determination with accuracy is from 0.01μg to 5μg in 25 ml. Quinine sulfate solution (0.011μg/m1) was used as setting reagent.