MEASUREMENT OF ACTIVITY-COEFFICIENTS IN HIGHLY DILUTE-SOLUTIONS .1.

A new variation of the exponential dilutor method introduced by Leroi et al. (1977) and improved by Duhem and Vidal (1978)) is presented, in which the time-dependent gas chromatographic analysis of the saturated vapour is replaced with glc analysis of the remaining liquid mixture. The new method is widely applicable and makes it possible to measure limiting activity coefficients of low-volatile compounds outside the measuring range of conventional measuring procedures. Hence it is suited for measuring the two limiting activity coefficients of a binary mixture within a wide range. The limiting activity coefficients measured in the present study are those of n-alkenes and cycloalkenes in DMF and NMP, and those of NMP in a series of saturated hydrocarbons. © 1990.