Pergamon S0045-6535(96)00087-2 Chemosphere, Vol. 32, No. 9, pp. 1699-1708, 1996 Copyright© 1996 ElsevierScienceLtd Printed in Great Britain. All rights reseawed 0045-6535/96 $15.00+0.00 MEASUREMENTS ON WATER CONTAINING DISSOLVED AND SUSPENDED MATTER FROM NATURAL SEDIMENTS Marc Londo ~, Martine I. Bakker m and S. Marca Schrap 2" Research Institute of Toxicology, Environmental Chemistry Group, Utrecht University, P.O. Box 80.058, NL-3508 TB Utrecht, The Netherlands. Institute for Inland Water Management and Waste Water Treatment, Ministry of Transport, Public Works and Water Management, P.O. Box 17, NL-8200 AA Lelystad, The Netherlands. (Received in Germany 14 August 1995; accepted7 February 1996) Abstract The presence of dissolved ,and suspended matter (DSM), originating from three different natural sediments, was measured as dry Weight concentrations (DW), dissolved organic carbon concentrations (DOC) and enhanced concentrations of three chlorobenzenes. The latter were measured in a recently developed method, in which the water containing DSM is contaminated with the chemicals by air in an air-bridge system. This method appears to be suitable for measuring enhanced concentrations in suspension water of relatively volatile compounds. DW and DOC concentrations and enhanced concentrations vary considerably between the three sediments. Moreover, the results are not in parallel, i.e. enhanced concentrations cannot be predicted by DW or DOC of the suspension water. This implies that neither DW nor DOC give a good description of the influence of DSM on the sorption behaviour of chemicals in water. Copyright © 1996 Elsevier Science Ltd Keywords: Hydrophobic organic chemicals, sorption, dissolved organic carbon, third phase. " To whom correspondence may be addressed. 1699