1. Department of Physical and Analytical Chemistry, Uppsala University, BMC, Box 577, SE-751 23 Uppsala, Sweden, AstraZeneca Process R&D, SE-151 85, Södertälje, Sweden, Department of Biochemistry and Organic Chemistry, Uppsala University, BMC, Box 576, SE-751 23 Uppsala Sweden, and Department of Physical and Analytical Chemistry, Uppsala University, BMC, Box 599, SE-751 24 Uppsala, Sweden