Analysis of atmospheric semi-volatile organic pollutants by adsorptiveenrichment and off-line supercritical fluid extraction—Gas chromatography

Abstract

Methods have been developed for determination of semivolatile organic pollutants in air. Extraction efficiencies for test compounds are > 83 %, and rsd's are < 3.4 % (n = 3). Atmospheric samples were collected from a variety of sites in Lanzhou, China by an adsorptive enrichment method. Over 50 organic pollutants were extracted by SFE with CO2 modified with methanol. Extracts were subjected to GC and GC-MS analysis. The results showed that one of the most serious polluted regions was an oil refinery, in which total concentration of pollutants amounted to 285.75 #g.m -3. The relationships between the total concentration of pollutants and sampling time and weather were also investigated. Results showed that pollution on sunny days is more serious than that on rainy days, while pollution is most serious during the evening.