I-DICARBOXYMETHYLAMINOMETHYL-2-HYDROXY-3-NAPHTHOIC ACID AS A SENSITIVE AND SELECTIVE FLUORIMETRIC REAGENT FOR BERYLLIUM AND FOR LANTHANUM AND LUTETIUM IN PRESCENCE OF OTHER LANTHANIDES

1-Dicarboxymethylaminomethyl-2-hydroxy-3-naphthoic acid (DHNA) forms fluorescent complexes with Al, Be, Ga, Hf, In, La, Lu, Mg, Sc, Th, Y, and Zr. The Be, La and Lu complexes have a metal : ligand ratio of 1:1. The beryllium complex shows maximal fluorescence at pH 6.8 with excitation-fluorescence maxima at 360 and 450 nm; linear calibration curves are obtained in the range 0.09-1.8 μg Be. In the presence of the calcium-EDTA complex, of 25 cations studied, only > 100-fold molar ratios of aluminium and > 10-fold molar ratios of magnesium and scandium caused interference in the determination of 0.1 μ mole of beryllium. Amongst 15 anions, > 100-fold molar ratios of phosphate, > 50-fold molar ratios of arsenate or oxalate and > 10-fold molar ratios of citrate, fluoride and tartrate caused low results. Lanthanum and lutetium can be determined at PH 10 and 370/460 nm in the range 7-28 μg even in the presence of a 3-fold molar ratio of the other lantlianides without interference. © 1968.