Characterization of Several Integrative Sampling Methods for Nitric Acid, Sulphur Dioxide and Atmospheric Particles

Abstract

Laboratory and field experiments were performed to evaluate integrative measurement methods for atmospheric nitrates, sulphate and sulphur dioxide. Denuder tubes and several filter media were tested under laboratory and field conditions. Effects of sampling variables such as temperature and relative humidity, flow rates, concentration, loading capacity and artifacts due to NO, NO₂ and SO₂ were also evaluated. The integrative filter sampling method and the ion chromatographic analytical procedure gave a measurement precision (relative standard deviation) of ±11.5 percent for particulate NO₃ ⁻ on Teflon and ±15.6 percent for gaseous HNO₃ on nylon; for both these constituents, the detection limit was about 0.1 μ m⁻³.