Dr. Weibel, Gisela


Titration laboratory

Chemical control on mineral formation

The OMNIS device at the Institute of Geosciences (Unibe) is the newly developed titration device manufactured by Metrohm AG. In particular, our device is equipped with: two independent dosing devices (burettes), pH electrode, conductivity probe, calcium-ion selective electrode (Ca-ISE), lead-ISE (coupled with a reference probe), visible light transmittance probe (Optrode) and magnetic stirrers. The OMNIS software allows the continuous monitoring of the different probes and, through the compilation of a specific method, every kind of pH-stat experiments can be performed on our device. The main applications related with geosciences are: nucleation of minerals from homogenous solutions supersaturated respect to such mineral, solubility determination, coprecipitation experiments, dissolution and precipitation kinetics of solid phases.

OMNIS device

For further information on the instrument, applications and training please contact:

From manufacturer: Metrohm

Application highlights:

  • Gebauer D., Völkel A. and Cölfen H., 2008, Stable Prenucleation Calcium Carbonate Clusters, Science, 5909, 1819-1822.
  • Di Lorenzo F., Burgos-Cara A., Ruiz-Agudo E., Putnis C.V. and Prieto M., 2017, Effect of ferrous iron on the nucleation and growth of CaCO3 in slightly basic aqueous solutions, CrystEngComm, 19(3), 447-460.