Binodal curves of the aqueous N-ethylpyridinium tetrafluoroborate ([EPy]BF4)+trisodium citrate (Na3C6H5O7). [EPy]BF4+ammonium citrate tribasic ((NH4)(3)C6H5O7). [EFy]BF4+sodium succinate (Na2C4H4O4) and [EPy]BF4+sodium tartrate (Na2C4H4O6) systems have been determined experimentally at T=298.15 K. The Merchuk equation and two other equations were used to correlate the binodal data. The effective excluded volume (EEV) values obtained from the binodal model for these four systems were determined. The Othmer-Tobias, Bancroft, two-parameter and Setschenow-type equations were used for the correlation of the tie-line data. The results show that good agreement was obtained with the experimental data with the two-parameter and the Setschenow-type equations. (C) 2012 Elsevier B.V. All rights reserved.