A simple and sensitive method for the determination of volatile halogenated organic compounds in sea water in the amoll−1 to pmoll−1 range

Abstract

Volatile halogenated organic compounds in sea water were determined in automated purge and trap systems connected to either a gas-chromatograph with an electron capture detector (GC–ECD), or a mass spectrometer (GC–MS). We show for the first time a miniaturised packed trap in combination with a narrow bore capillary column for the analysis of sea water. Detection limits of amol l⁻¹ to fmol l⁻¹ range for GC–ECD and fmol l⁻¹ to pmol l⁻¹ for GC–MS are achieved with a micro-trap filled with a porous polymer for water samples of 27 ml. The trap is cooled to moderate temperatures, +5°C to −10°C by means of circulating water. The repeatability (RSD) of the compounds determined in sea water were 4% or lower. The method was shown to facilitate the assessment of a number of naturally produced halocarbons important for the chemistry of the atmosphere, in the Arctic Ocean.