Study of the end‐group contribution to ToF‐SIMS and G‐SIMS spectra of poly (lactic acid) using deuterium labelling |
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| Authors: | R Ogaki F M Green I S Gilmore A G Shard S Luk M R Alexander M C Davies |
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| Institution: | 1. Laboratory of Biophysics and Surface Analysis, School of Pharmacy, University of Nottingham, Nottingham, UK;2. Quality of Life Division, National Physical Laboratory, Teddington, Middlesex, UK;3. Molecular Profiles Ltd, Nottingham Business Park, Nottingham, UK;4. Laboratory of Biophysics and Surface Analysis, School of Pharmacy, University of Nottingham, Nottingham, UKLaboratory of Biophysics and Surface Analysis, School of Pharmacy, University of Nottingham, Nottingham, UK. |
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| Abstract: | In this study, polymeric (MW 50 000) and oligomeric (MW 2000) poly (lactic acid) (PLA), both with and without end‐group deuterium exchange, were analysed using static secondary ion mass spectrometry (SSIMS) to investigate the contribution of end‐group‐derived secondary ions to the SSIMS spectra. By monitoring the SSIMS intensities between the non‐deuterated and deuterated PLA, it is evident that the only significant end‐group‐derived secondary ions are nM + H]+ (n > 1) and C4H9O2+. The gentle‐SIMS (G‐SIMS) methodology was employed to establish that deuterated fragments were produced through low energy processes and were not the result of substantial rearrangements. It was noted that end‐group‐derived secondary ions had higher G‐SIMS intensities for oligomeric PLA than polymeric PLA, showing that these secondary ions are simple fragment products that are not the result of rearrangement or degraded product ions. Copyright © 2007 John Wiley & Sons, Ltd. |
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| Keywords: | SSIMS G‐SIMS fragmentation mechanism biodegradable polymer |
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