Abstract: Continuous sampling technique—an improvement of the gas stripping method has been proposed for the determination of large value activity coefficients at infinite dilution (γ~∞>10~2). In this technique, the outlet gas flow from the equilibrium cell is introduced directly into a detector of a gas chromatograph. The curve of the concentration of the solute in the flow gas versus the stripping time will be gained continueously, and the variation slope can be obtained more precisely. Experimental activity coefficient results have been compared with the literature values which were obtained by the other methods.

Key words: Large value activity coefficients at infinite dilution, Continuous sampling technique, Gas stripping method