Disk mini-adsorbers with radial flow for determination of 234Th concentration in seawater

A modified method has been developed for measuring the 234Th concentration in seawater, which is based upon the use of MnO2-impregnated disk mini adsorbers with radial flow connected in-line and the direct beta counting of 234Th and/or its daughter 234mPa. This allows determining the 234Th concentration in a relatively small volume of seawater (20–50 L) with the possibility to check the extraction efficiency in every individual sample. The field testing, which was carried out at different areas of Sevastopol Bay during different seasons, has shown applicability of the proposed method to evaluate particle fluxes in marine environments within a wide range of concentrations of suspended matter.