N-Aryl-3-Aminopropionic acids as selective reagents for the determination of copper in metallurgical products

Abstract

Analytical characteristics of N,N-di(2-carboxyethyl)aniline (I), N,N-di(2-carboxyethyl)-3,4-xylidine (II), N-(2-carboxyethyl)anthranilic acid (III), N,N-di(2-carboxyethyl)-4,5-dimethylaminoazobenzene-4′-sulfonic acid (IV), and N-(2-carbamoylethyl)anthranilic acid (V) were studied. The factors affecting the selectivity of I–V for Cu(II) ions (basicity of the amino group, nature and positions of substituents in the benzene ring, and geometry of chelate cycles) were analyzed. The optimum conditions were found and procedures were developed for the spectro-photometric determination of copper in metallurgical products. The high selectivity of I–V for Cu(II) ions allows the determination without preliminary separation of concomitant components in aqueous solutions without organic solvents. Compound II exhibits the best analytical characteristics: the analytical range of copper 3–20 mg/L, detection limit 0.7 mg/L, ɛ(λ = 252 nm) = 3290 L mol−1 cm−1, and pH 6.0 (ammonia-acetate buffer solution).