Development of a LC system for trapping and enrichment of related impurities prior to analysis by MS or NMR

The impurities and degradation products which always are formed when a drug substance is synthesised or exposed to humid air, light, heat, high/low pH, oxygen, etc needs to be identified. This is done by mass spectroscopy (MS) and nuclear magnetic resonance spectroscopy (NMR).
The performance of MS is, unfortunately, hampered by the buffers normally used for liquid chromatography (the most frequently used analytical technique within a pharmaceutical company). Consequently, it would be of great interest to somehow remove these buffers before the analyte is injected into the MS.

NMR is an excellent analytical tool but its relatively low sensitivity causes problems when analysing impurities and degradation products. In most cases it is necessary to enrich the analyte prior to analysis.
The purpose of the suggested diploma work would be to setup and evaluate a LC system that can be used to trap one of the peaks in a chromatogram on a short column, subsequently wash away the buffer salts and finally elute the analyte in a small volume of organic modifier which also is used to transfer the analyte into the MS or the NMR instrument. In order to enrich the analyte the tapping procedure can be repeated a number of times before eluting the analyte.

For questions or more extensive description contact:
Patrik Petersson at +46 (0)46 33 67 61