Identification of Soil Organics Using a Gas Chromatographic Mass Spectrometric Method

Book excerpt: As part of a study on the role of natural organics in determining the physical properties of soils, the use of combined gas chromatographic/mass spectrometric methods for identification of the more volatile organic chemicals in soils were explored. Soil was first treated at 100, 150, and 200C to select the optimum temperature where minimum pyrolysis of soil organic matter occurred. The vapors from three soils heated in a closed system at 150C were then analyzed. Subsequent refinement in technique involved collection of vapor from the three soils maintained at 150C using a constant flow sample holder/inlet system. About 50 organic compounds were identified. While application of this approach is restricted to the volatile compounds in the lower molecular weight range, conditions of analysis are thought to be suitable for identification of compounds originally present as opposed to pyrolysis products of soil organic matter. (Author).