Crystalline lamellar calcium phosphate retained 4-aminobenzoic acid inside its cavity without leaching. The intense infrared bands in the 1033 and 1010 cm(-1) interval confirmed the presence of the phosphonate groups attached to the inorganic layer, with sharp and intense peaks in X-ray diffraction patterns, which gave basal distances of 712 and 1578 pm for the original and the intercalated compounds, respectively. Solid-state P-31 nuclear magnetic resonance spectra presented only one peak for the phosphate groups attached to the main inorganic polymeric structure near -2.4 ppm. The adsorption isotherms from ethanol gave the maximum adsorption capacities of 6.44 and 3.34 rnmol g(-1) for nickel and cobalt, respectively, which stability constant and distribution coefficient followed Co > Ni. (C) 2012 Elsevier Ltd. All rights reserved.