A sampling device for collection and analysis of volatile halocarbons in coastal and oceanic waters

A simple device for collection of sea water samples for measurement of vola tile halocarbons has been developed. This device enables collection of samp les without contact with the atmosphere and by introducing the sample direc tly into the analytical circuit eliminates secondary handling of the sample s and the risks of contamination associated with it. The device is chemical ly inert and samples can be stored without contamination for periods of up to 16 h in the case of chlorofluorocarbons (CFCs) and CCl4 and several days in the case of other volatile organic halocarbon compounds before analyses . Standard deviations, as a percentage of the average concentrations measur ed, varied between 1.4 and 5.7% for a range of halocarbons in coastal water s and were about 2% for CFC-11 and CFC-12 in the oceanic surface waters. De tection limits were less than 0.17 ng l(-1) for volatile halocarbons and 0. 015 pmol l(-1) for CFC-11 and CFC-12. The sampling device has been routinel y used for collection of estuarine, coastal and oceanic waters. Results obt ained in the coastal waters of Douarnenez Bay and the oceanic waters of the north-east Atlantic are presented as examples.