A comparison of interstitial water isolation methods demonstrates centrifugation with aspiration yields reduced losses of organic constituents

Spiked sediment and seawater were used to evaluate the recoveries of neutral organic compounds in interstitial water (IW) separated by centrifugation and sampled using a unique aspiration system. An average recovery of 94%±0.8% (SE, N=116) of ten polynuclear aromatic hydrocarbons and four chlorinated hydrocarbons was obtained from spiked estuarine IW using the aspiration system. Centrifugation of spiked sediment using the aspiration system recovered significantly higher IW concentrations of acenaphthene, phenanthrene, fluoranthene and DOC than did IW filtration, or in situ IW collection by fritted glass, or membrane covered, vessels.