MOST compounds of biochemical interest have only limited solubility in organic solvents, and the useful fluors described to date have only limited solubility in aqueous solutions. This basic incompatibility has limited the application of liquid scintillation counting methods in many biochemical tracer studies. The method described below permits direct counting of aqueous solutions (or alcoholic solutions). In addition, it permits quantitative recovery of the sample in its original form for further analyses, often an important advantage when the quantity of sample available is limited.