1. Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck, Austria, Biocrates Life Sciences GmbH, Innrain 66, A-6020 Innsbruck, Austria, and Department of Urology, Medical University of Innsbruck, Anichstraβe 35, A-6020 Innsbruck, Austria