A SIMPLE AND SENSITIVE METHOD FOR THE DETERMINATION OF VOLATILE HALOGENATED ORGANIC-COMPOUNDS IN SEA-WATER IN THE AMOL 1(-1) TO PMOL 1(-1) RANGE

Volatile halogenated organic compounds in sea water were determined in automated purge and trap systems connected to either a gas-chromatogr aph with an electron capture detector (GC-ECD), or a mass spectrometer (GC-MS). We show for the first time a miniaturised packed trap in com bination with a narrow bore capillary column for the analysis of sea w ater. Detection limits of amol l(-1) to fmol l(-1) range for GC-ECD an d fmol l(-1) to pmol l(-1) for GC-MS are achieved with a micro-trap fi lled with a porous polymer for water samples of 27 ml. The trap is coo led to moderate temperatures, +5 degrees C to -10 degrees C by means o f circulating water. The repeatability (RSD) of the compounds determin ed in sea water were 4% or lower. The method was shown to facilitate t he assessment of a number of naturally produced halocarbons important for the chemistry of the atmosphere, in the Arctic Ocean. (C) 1997 Els evier Science B.V.