1. Michael Barber Centre for Collaborative Mass Spectrometry; Manchester Institute for Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
2. Laboratoire de Chimie Physique Moléculaire; École Polytechnique Fédérale de Lausanne; 1015 Lausanne Switzerland
3. School of Science; RMIT University; 124a La Trobe Street Melbourne VIC 3001 Australia
4. The School of Physics and Astronomy; James Maxwell Clark Building; The University of Edinburgh; Edinburgh EH9 3FD UK