The sampling and determination of halocarbons in ambient air using concentration on porous polymer

The levels of halocarbons have been determined in rural air in central Michigan using a sampling procedure employing pre-concentration on a porous polymer. The samples were analyzed by gas chromatography (GC) with an electron capture detector. Both qualitative and quantitative confirmation of the results were achieved by GC-mass spectrometry. Trichlorofluoromethane, chloroform, 1,1,1-trichloroethane, carbon tetrachloride, trichloroethylene and perchloroethylene were determined in the range of 30-130 parts per trillion. These concentrations agree well with data obtained by others in Washington state and Ireland indicating even distribution of the halocarbons in these latitudes.