Gas chromatographic methods for ambient halocarbon measurements

Abstract Gas Chromatographic procedures for the measurement of SF6, COC12 and twelve atmospheric halocarbons, including vinyl chloride, have been developed. The identities of these relatively unstudied important atmospheric constituents were established conventionally by extensive empirical cross checking of retention data and then confirmed by the novel application of electron attachment kinetics in a dual electron capture detector system. Nine packings were found useful for the measurement of one or more of the compounds under study. In an ongoing study of the fates of halocarbons, phosgene synthesis has been demonstrated in a smog chamber experiment in which a mixture of 1 ppm C2Cl4 and 0.5 ppm NO2 in air (RH=50%) was irradiated with simulated sunlight. Phosgene identity was confirmed by its ionization efficiency and retention data on a didecyl phthalate column. Gas phase coulometry can only be used for non‐reactive electron absorbers and suffers significant error for reactive compounds such as phosgen...