Joana Diekmann

Coupling of Capillary Electrophoresis with Nuclear Magnetic Resonance Spectroscopy for the Analysis of Pharmaceutical and Environmental Relevant Compounds Joana Diekmann

Master's Thesis from the year 2009 in the subject Chemistry - Analytical Chemistry, grade: 1,0, University of Hannover (Anorganische Chemie), language: English, comment: This Master Thesis was awarded with the "E. ON Future Award 2010" and it was carried out at the Leibniz University Hannover, Faculty of Natural Sciences, Institute for Inorganic Chemistry, Department of Analytical Chemistry, in cooperation with the Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Livermore, CA, USA. , abstract: Separation and identification of mass-limited chemical samples is the key to understand the complex nature of pharmaceutical and environmental systems. High efficiency separation techniques, such as capillary electrophoresis (CE), coupled to a non-destructive, information-rich detection, such as nuclear magnetic resonance (NMR) spectroscopy, have revolutionized the ability to separate and identify components in small sample volumes. Using this hyphenated system, structure elucidation of analytes separated during an electrophoretic process can be performed using NMR as an on-line detector. Although sensitivity remains an issue for on-line NMR detection, capillary NMR spectroscopy using microcoils has emerged as a major breakthrough for increasing the mass-sensitivity of NMR spectroscopy, because the limit of detection is proportional to the coil diameter. A further development is the miniaturization of the magnet enabling the possibility of a truly portable NMR system. This portable, low-cost NMR sensor, coupled to the rapid CE separation system could enable high-throughput and on-site identification of nanoliter amounts of solution. Furthermore, CE can provide on-line pre-concentration via electrokinetic injection or other stacking techniques to increase the sample concentration. In this research, coupling CE to a laboratory-scale NMR and to a portable NMR system are investigated, with the emphasis on the development of the miniaturized system.