The clean lab of the group for Marine Isotope Geochemistry is metal-free and (nearly) particle-free. This allows the processing of seawater and sediment samples for the analysis of trace element isotopes and concentrations. In order to analyse trace elements in the ocean (concentrations in the ppb (10-9)-range), they have to be preconcentrated from seawater and the elements of interest need to be isolated from other elements that would interfere during isotope analysis on the mass spectrometer. The smallest contamination of our samples through dust particles or metals, which contain much higher concentrations of these elements, would mask the natural concentrations of these elements in seawater and therefore distort the results.
An article with further details can be found here.