AN IMPROVED DIALYSIS SAMPLER FOR THE IN-SITU COLLECTION OF LARGER VOLUMES OF SEDIMENT PORE WATERS

Anew Volume Enhanced Sediment Porewater Sampler (VESPOS) for the in si tu separation of pore water from aquatic sediments is described. This sampler offers several improvements over conventional in situ sediment pore water sampling devices, particularly for the collection of a lar ge sample volume (30 ml); simplification in the assembly of the sample r and recovery of the sample; and, consequently, minimizing the risks of sample contamination. The large volume of pore water sampled within a 2-cm interval increases the analytical potential. The sampler signi ficantly reduces the labour and equipment involved in sediment pore wa ter sampling, particularly during retrieval of the samples.