TEXT R. Zurbriggen^1*, Th. Bühler², A. Wetzel³, L. Huwiler¹, U. Heini¹, U. Pieles², M. Herwegh^{3                                                                                1}Nouryon (former Akzo Nobel Chemicals AG, and Elotex AG), Sempach Station/Switzerland                  ²Institute for Life Science, University of Applied Sciences Northwestern Switzerland, Muttenz/Switzerland                  ³Institute of Geological Sciences, University of Bern, Bern/Switzerland                                                                      *Corresponding author: ; Tel.: +41 41 469 69 43