Protocoles d'extraction chimique de la matière organique particulaire : application au domaine estuarien

There are several bio geochemical methods of studying particulate organic matter (0,45-300 µm). The main techniques employed are described ; special attention has been paid to extractive processes (chemical attack of samples and study of extracted fraction). Although these techniques are simple, various difficulties can arise : results obtained by various authors cannot be compared when techniques used differ. Furthermore the environmental interpretation of extracted functions is not always very clear. Extractive methods, which most often use harsh chemical extractants, do not provide accurate measurements of the importance of labile organic fraction. We propose therefore a series of chemical attacks of increasing strength and a correlation of results with those obtained by measurements of the organic matter degradability in samples (e.g. bacterial heterotrophic activities or incubation)