Institution: | (1) Institute for Reference Materials and Measurements, European Commission – JRC, B-2440 Geel, Belgiume Tel.: +32 14 57 17 02; Fax: +32 14 59 19 78; e-mail: vnevel@irmm.jrc.b, BE;(2) National Institute of Standards and Technology, Gaithersburg, MD 20899, USA, US;(3) Johannes Gutenberg University Mainz, J. J.-Becher-Weg 24, D-55099 Mainz, Germany, DE |