Analysis of halogenated C-1/C-2-trace compounds in marine atmosphere

Patterns of volatile ECD-active substances in marine air at the ultra trace level were investigated. The protocol used carbon based adsorbents, thermo desorption and thick film HRGC-ECD together with a second ECD in line with oxygen doped make-up gas. The latter ECD mode leads to an increased sensiti vity for chloromethane, dichloromethane, and other important chlorinated su bstances with an otherwise low response at an ECD driven with oxygen-free n itrogen or argon/methane, The experimental set-up is easily to employ. Air samples were taken on two cruises Of the German research vessel R/V "Polars tern" in the Atlantic Ocean to determine the background pattern of all vola tile halocarbons from CF3Cl to CHI3 in marine air.