Metrohm says that its stopped-flow dialysis allows convenient analysis of demanding samples carrying high organic loads.
In complex matrices carrying high organic loads such as waste water, soil eluates or dairy products, extensive sample preparation is mandatory to prevent destruction of the column.
Traditional preparation techniques such as Carrez precipitation should not be used as they cannot be automated and are error prone, according to Metrohm.
The company offers its compact stopped-flow dialysis as an alternative.
This fully automated sample preparation setup is based on the selective diffusion of ions from one liquid (sample/donor solution) to another (acceptor solution) through a membrane.
Contrary to dynamic dialysis, where two solutions continuously pass through the dialysis module, the acceptor solution is stopped until its concentration is the same as that in the donor solution.
This stopped-flow procedure takes between 10 and 14 minutes and can be directly coupled to an IC setup.
As the dialysis is performed during the recording of the previous sample's chromatogram, the overall analysis time is not significantly prolonged.