Application of hot-stage microscopy direct analysis in real time mass spectrometry (HDM) to the analysis of polymers
| Autor: | Sophie E. Pownall, Gareth M.B. Parkes, Lindsay P. Harding, Gage P. Ashton |
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| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Chemistry 010401 analytical chemistry Organic Chemistry Analytical chemistry Polymer Temperature cycling Mass spectrometry 01 natural sciences DART ion source Thermal expansion 0104 chemical sciences Analytical Chemistry Microscopy Mass spectrum Ion trap Spectroscopy |
| Zdroj: | Rapid communications in mass spectrometry : RCMREFERENCES. |
| ISSN: | 1097-0231 |
| Popis: | Rationale Polymers are ubiquitous, and characterisation of their chemical, thermal and mechanical properties is important in many applications. Hot-stage microscopy Direct Analysis in Real Time mass spectrometry (HDM) is a new technique which combines optical measurements with the benefits of ambient ionisation mass spectrometry. Physical and chemical information can be obtained as a function of sample temperature, in real time. Methods Samples were placed on a miniaturised hot-stage between a custom-made Direct Analysis in Real Time (DART) source and the inlet of an ion trap mass spectrometer, and subjected to both linear and cycled temperature programmes. Optical images were collected using a digital microscope and mass spectra (positive and negative ion) were recorded simultaneously. Results Mass spectra and optical images were used to monitor the thermal expansion and release of volatile oligomers from both medical and domestic grades of silicone. Series of ions separated by 74 m/z units were observed, consistent with the SiOMe2 monomer; the median mass of these increased with increasing temperature up to the decomposition point (340-400°C). The abundance of volatile material produced decreased with repeated thermal cycling. The coefficients of thermal expansion were calculated from optical data and were in agreement with conventional measurements (2.7-3.6 × 10-4 °C-1 ). Two samples of beach sand analysed for the presence of microplastics were found to contain polyethylene and polystyrene, respectively. Conclusions Results indicate that the novel technique of HDM can be successfully applied to the characterisation of a wide range of polymers including those in complex matrices. |
| Databáze: | OpenAIRE |
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