Extraction of carcinogenic aromatic amines from aqueous solution using calix[n]arene derivatives as carrier

The extraction abilities of p-tert-butylcalix[n]arenes (n = 6, 8) and their carboxylic acid and methyl ester derivatives upon some carcinogenic aromatic amines have been investigated. The separation and quantification of aromatic amines were performed by high-performance liquid chromatography with Ace 5 C18 column and diode array detection. The optimum pH values for aromatic amines sorption were observed at pH 4.0, 7.0 and 8.5 for all calixarene derivatives. In batch sorption experiments of selected carcinogenic aromatic amines, the experimental results show that octacarboxylic acid derivative of p-tert-butylcalix[8]arene exhibited a better affinity than other compounds towards all aromatic amines species at almost all pHs. The sorption of aromatic amines by carboxylic acid derivatives of p-tert-butylcalix[n]arene indicates that carboxyl groups play the major role for the formation of hydrogen bonds and electrostatic interactions between sorbent and aromatic amine.