In order to study the equilibria of long-chain alkanes and supercritical fluids, a high-pressure phase equilibrium cell has been designed, constructed, commissioned and tested against reliable literature data. Phase equilibrium data for propane-dotriacontane (nC(32)H(66)) have been measured between 378.2 and 408.2 K. Emphasis was placed on measuring equilibrium data in the mixture critical region. Ten cubic and five non-cubic equations of state have been applied to the phase equilibrium data at 408.2 K. The modified Patel-Teja (MPT), as a cubic EOS, and statistical associating fluid theory (SAFT), as a non-cubic EOS, give the best-fit of the data at 408.2 K. The phase equilibrium predictions of the SAFT EOS significantly deteriorated as the critical point of the solvent was approached. (C) 2002 Elsevier Science B.V. All rights reserved.