Comparison of headspace and gas-stripping methods for determining the Henry''s law constant (H) for organic compounds of low to intermediate H

A computer-controlled headspace sampling and gas chromatographic system (HS-GC) was used to measure Henry's Law constant (H) for organic compounds. The HS-GC results, extrapolated to ambient temperature in Clausius-Clapeyron type equations, compared well with values obtained using a gas-stripping method at ambient temperature. The HS-GC method provided the temperature-dependence of H so that it can be calculated at any temperature, which is essential when comparing laboratory results with values of H derived from air/water distributions in the environment.