A Large-Volume Sampling Assembly for the Determination of Synthetic Organic and Petroleum Compounds in the Dissolved and Particulate Phases of Seawater

Abstract

A system for the in situ sampling of subsurface seawater for the determination of synthetic organic and petroleum compounds in concentrations of picograms per litre is described. Seawater from in front of the bow of the vessel was pumped through a stainless steel tube into a cleanroom, through a glass fiber filter, and through parallel or serial Teflon® columns packed with a porous polyurethane foam (PPF) solid adsorbent. The majority of hydrocarbons associated with seawater particles were quantitatively recovered. The efficiency of the foam columns in extracting the dissolved phase was determined by intercaiibration with liquid–liquid extraction using cyclohexane and by separate analyses of two columns mounted in series. Recovery of polychlorinated biphenyls, several chlorinated hydrocarbon biocides, and aromatic hydrocarbons was quantitative with a single PPF column. Measured concentrations were in the low picogram per litre range for chlorinated organics and the nanogram per litre range for total petroleum. Reduction of contamination during sampling remains of paramount importance in the determination of hydrocarbon concentrations in seawater.