Matière organique dissoute dans l'estuaire maritime du St-Laurent — comparaison et choix des méthodes

To study quantitatively and qualitatively the dissolved organic matter in the St. Lawrence maritime estuary, a comparison between the different extracting methods has been undertaken. We propose two of them; one based on liquid–liquid extraction, the second by adsorption on a resin (Amberlite XAD-2). The methods used remove different spectrums of organic compounds from sea water. Hydrocarbons were found to constitute the major part of the extracts varying between 3 and 5 mg/liter. None of the methods used extracts more than 20% of the total organic matter present. The concentration of the organic chloro-compounds in the water column is in the order of 80 ppb.