Determination of Volatile Aromatic Hydrocarbons in Estuarine and Coastal Sediments Using Gas Syringe Injection of Headspace Vapours and Gas Chromatography With Flame-ionisation Detection

A simple, low cost flame-ionisation detection method for the determination of volatile aromatic compounds in estuarine and coastal sediments is described. Headspace vapours are drawn from a modified sample vessel at 80 "C and injected by means of a gas-tight syringe with a valved needle. The method eliminates the difficulties norma I ly encou ntered with solvent extraction and dynamic " non-equ i I i bri u m " heads pace methods. The effect of varying the sample preparation parameters is discussed and results giving the optimised values are presented. Relative standard deviations of less than 2% were achieved for a variety of sub-marine and tidal sediments and the results were found to be superior to those given by an existing solvent extraction method. The limits of detection of the method are below 0.5 pg kg-1 (dry mass) for ten key volatile organic aromatic compounds and the response is linear up to at least 200 pg kg-1.