The Determination of Henry’s Constant for Volatile Organics by Equilibrium Partitioning in Closed Systems

Abstract

Equilibrium Partitioning in Closed Systems (EPICS) is a simple technique proposed for determining the Henry’s constants of volatile organics in water. It requires no special apparatus, and obtains results from the measurement of gas concentration ratios so that the preparation of standard curves for determining exact concentrations is not required. Henry’s constants for five priority pollutants at 10 to 30°C were measured with this technique and compared with literature values and with Henry’s constants measured in a bubble column. The results indicate that the technique is accurate. In addition, the technique is unencumbered by equilibration problems which limit the utility of other methods for determining Henry’s constant.