The instrument consists of a base and stand assembly, sample holder and gas distribution system. Test tubes are held in place by a spring-loaded sample holder and support tray. Each position is numbered. The gas passes through an adjustable flow meter to the distribution manifold. Flexible tubing leads to valve-tube assemblies at each position. Depending on the test-tube size and solvent volume they can be individually raised or lowered to the correct height. Needles blow gas onto the surface of the solution resulting in rapid evaporation of the solvent. All materials used are laboratory quality and can withstand contact with organic solvents.