Extraction equilibria of 2,4,6-Trinitrophenol (picric acid (PAH)) between aqueous and organic phases was investigated at 298.15 K. All experiments was reported on the extraction of picric acid by amberlite LA2 which is secondary amine dissolved in different seven (7) esters such as diethyl malonate, dimethyl phthalate, diethyl glutarate, propyl acetate, diethyl succinate, diethyl sebacate, ethyl propionate, as well as single diluents. Experimental results obtained from batch extraction were evaluated in respect to distribution coefficients (K-D), loading factors (T-T), stoichiometric loading factor (T-S), separation factor (S-f) and extraction efficiency (E). The dimethyl phthalate gave highest synergistic effect with LA2 as extraction efficiency value of 95%. The highest values of possible equilibrium complexation constants for (acid/amine) (1:1) K-11 was determined as 10.969 for dimethyl phthalate at 1.762 mol kg(-1) amine concentration. (C) 2016 Elsevier B.V. All rights reserved.