1. Department of Chemistry, University of Pretoria, Lynnwood Road,
Hatfield, Pretoria 0001, South Africa
2. Processing Laboratory, Impala Platinum Limited, 123 Bethlehem Drive, Rustenburg 0299, South Africa
3. Joint Mass Spectrometry Centre, Cooperation Group “Comprehensive Molecular Analytics”, Helmholtz Zentrum München, Neuherberg D-85758, Germany
4. Joint Mass Spectrometry Centre, Institute of Chemistry, University of Rostock, Rostock D-18051, Germany