Collection and Processing of Airborne Chemical Information, II

Abstract

A previous method (1) for collection of airborne chemical information through equilibration and processing of the samples was considerably improved. The essential new features are a sampler in the form of a fluidized bed of Teflon powder coated with Apiezon L stationary phase, a redesigned collector-injector, and a motor-operated bellows apparatus for injecting samples into the column by use of a carrier gas-derived helium charge. A calibration method is described that permits relating the concentration of a known substance in air to its peak area. The capability of the new method permits analysis of airborne organic vapors at concentrations of the order of 1 ppb in air and well below the odor thresholds for the several substances tested. The concept of Tanimoto distance is proposed as a convenient, simple construct for characterizing the overall similarities of olfactronic signatures of complex sources.