A pumping system for underway sampling of dissolved and particulate trace elements in near-surface waters

A method for the collection of large-volume samples of oceanic particles is described. Near-surface seawater is pumped from below the ship to a continuous-flow centrifuge at rates of up to 1.2 m 3 h −1 . The seawater is in contact with polyethylene, polypropylene, Teflon and titanium materials only. The retention efficiency of the centrifuge for marine particles is the same as for standard membrane filters, as shown by comparisons with separate samples from Go-Flo bottles. The pumping system is non-contaminating with respect to both particulate and dissolved species. Several subsampling facilities for additional chemical constituents and other parameters can be supplied simultaneously due to the modular design of the system and the high flow rates