Recent interest in studying molecular interactions in supercritical fluid environments has raised several important experimental questions. Chief among those is how to prepare a supercritical fluid environment when beginning with a sample of mixed phases at standard ambient temperature and pressure. We present a reliable technique for mixing a gas phase solvent with a liquid co-solvent and a solid phase molecule of interest. Furthermore, this technique is generally applicable to many experimental investigations involving supercritical fluids. (C) 2002 Elsevier Science B.V. All rights reserved.