1989 Volume 38 Issue 12 Pages 674-680
The reactions of salicylaldehyde with primary amines and metal ions to form Schiff-base complexes were investigated for the analysis of amines. ο-Aminophenol (OAP) emits a strong fluorescence in the presence of aluminium(III) by yielding an aluminium complex with salicylidene-ο-aminophenol. The fluorometric determination procedure of OAP using the aluminium complex was established. The recommended procedure is as follows: Take 1 ml of a sample solution containing less than 2×10-7 mol of OAP, add 3 ml of the reagent solution {0.01 M salicylaldehyde in methanol: 0.01 M Al(NO3)3·9H2O in water: 20% sodium acetate-HCl buffer (pH 5.3)=1:1:1}, and allow to stand for 30 min at room temperature (2035°C). Then dilute the mixture to 25 ml with water. Measure the relative fluorescence intensity at 495 nm with an excitation wavelength of 400 nm using (0.22)μg/ml uranine aqueous solution as the reference standard. OAP can be determined in the range of (4×10-92×10-7)mol/25 ml within a relative standard deviation of 3%. The detection limit of OAP is 5×10-10mol/25 ml. According to this procedure, only OAP related compounds showed a fluorescence among the 17 aromatic amines examined. m- and p-Aminophenol, and aniline at 100-fold concentration of OAP did not interfere with the determination of OAP. Aliphatic amines did not interfere at a 1000-fold excess.
