A vacuum-operated pore water extractor for estuarine and freshwater sediments

An illustrated description is given of equipment developed for extracting interstitial water from aquatic sediments. It consisted of a fused-glass airstone attached with aquarium airline tubing to a polypropylene syringe (30 or 60 cc); the airstone was inserted into the sediment and a vacuum was created by retracting and bracing the syringe plunger. A hand-operated vacuum pump attached to a filtration flask was also tested as an alternative vacuum source. Extraction time was longer for fine sediments than for sandy sediments. The sediment around the airstone acted as a filter, and the extracted pore water was clear, except for the first few ml. Since there was no exposure to the air, volatile compounds and the in situ characteristics of the porewater were retained. There are 43 references.