Application of Computer Controlled High Resolution Mass Spectrometry to the Analysis of Air Pollutants

An AEI-MS9 high resolution mass spectrometer interfaced with a PDP-12 digital computer has been adapted for the multicomponent analysis of air pollutants. Air sampling techniques for particulate and gaseous pollutants have been developed which are compatible with the mass spectrometric system. A single stage impactor has been designed for sampling particulate matter of particle diameters greater than 1–2 μm. The remainder of the particulate matter is collected on a glass fiber filter. Gaseous pollutants are collected on a styrene-divinylbenzene copolymer (Chromosorb 102).

The particulate samples are introduced directly into the mass spectrometer utilizing a temperature programed insertion probe. Gaseous pollutants are desorbed from the copolymer directly into the mass spectrometer by heating. Analysis of composite mass spectral data is facilitated through the use of a digital computer utilizing newly developed computer programs. Final computer output yields qualitative and quantitative results for up to 300 pollutants. Organic pollutants identified in particulate matter include polycyclic aromatic compounds, alkyl chlorides, polychlorinated aromatics, substituted benzenes and organic acids. Composite quantitative results are reported for alkanes and alkenes in the following groups: C₁₅-C₃₀, C₃₀-C₅₀ and Cso-polymeric. Inorganic pollutants identified include As₄O₆, H₂SO_4/ (NH₄)₂SO₄, (NH₄)₂SO₃, NaHSO₄, NH₄NO_3/ NaNO₃, NH₄CI, SeO₂, I₂, elemental sulfur, and elemental cadmium.