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

Abstract

A simple device for collection of sea water samples for measurement of volatile halocarbons has been developed. This device enables collection of samples without contact with the atmosphere and by introducing the sample directly into the analytical circuit eliminates secondary handling of the samples and the risks of contamination associated with it. The device is chemically 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 measured, varied between 1.4 and 5.7% for a range of halocarbons in coastal waters and were about 2% for CFC-11 and CFC-12 in the oceanic surface waters. Detection 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 routinely used for collection of estuarine, coastal and oceanic waters. Results obtained in the coastal waters of Douarnenez Bay and the oceanic waters of the north-east Atlantic are presented as examples.