EVALUATION OF THE SORPTION OF VOLATILE ORGANIC-COMPOUNDS BY UNSATURATED CALCAREOUS SOIL FROM SOUTHERN NEVADA USING INVERSE GAS-CHROMATOGRAPHY

The vapor phase sorption of several volatile organic compounds (VOCs) by a calcareous soil from Southern Nevada has been measured using inve rse gas chromatography (IGC). For dry soil, sorption isotherms are app arently nonlinear, and finite desorption kinetics contribute to the ch romatographic peak shapes. Competitive sorption between VOCs and water was examined by adding water to the carrier gas and by directly wetti ng the soil. Even a small addition of water drastically decreased the sorption of non-hydrogen-bonding VOCs by the soil and eliminated the e ffect of finite sorption kinetics on the chromatographic peak shapes. However, hydrogen-bonding compounds still exhibited nonlinear sorption isotherms and finite sorption and desorption kinetics in the presence of water.