Academic Journal
Calibration of hydroxyacetonitrile (HOCH2CN) and methyl isocyanate (CH3NCO) isomers using I− chemical ionization mass spectrometry (CIMS)
| العنوان: | Calibration of hydroxyacetonitrile (HOCH2CN) and methyl isocyanate (CH3NCO) isomers using I− chemical ionization mass spectrometry (CIMS) |
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| المؤلفون: | Z. Finewax, A. Chattopadhyay, J. A. Neuman, J. M. Roberts, J. B. Burkholder |
| المصدر: | Atmospheric Measurement Techniques, Vol 17, Pp 6865-6873 (2024) |
| بيانات النشر: | Copernicus Publications, 2024. |
| سنة النشر: | 2024 |
| المجموعة: | LCC:Environmental engineering LCC:Earthwork. Foundations |
| مصطلحات موضوعية: | Environmental engineering, TA170-171, Earthwork. Foundations, TA715-787 |
| الوصف: | The toxic reduced nitrogen compound methyl isocyanate (CH3NCO, MIC) has been reported as present in wildfire and biomass burning emissions, agricultural fumigation plumes, and indoor air. Its isomer, hydroxyacetonitrile (HOCH2CN, glycolonitrile, or HAN) has not been observed in the Earth's atmosphere to date. In this study, absolute sensitivity calibrations for these isomers using two I− chemical ionization mass spectrometry (I-CIMS) instruments, the time-of-flight (ToF) and quadrupole (Quad) instruments, commonly used in laboratory and field measurements, were performed, for the first time, over a range of ion-molecule reactor temperatures (10–40 °C) and I(H2O)− / I− ratio (0.01–1). This study demonstrates that I-CIMS, under typical operating conditions, is not sensitive to MIC with limits of detection (LOD) of > 860 and > 570 ppb for the ToF and Quad I-CIMS instruments, respectively. Both I-CIMS instruments are, however, highly sensitive to the HAN isomer with 0.3 and 3 ppt LODs for the ToF-CIMS and Quad-CIMS instruments, respectively. The present results show that several recent field studies using I-CIMS instrument detection have misattributed the C2H3NO signal to MIC. This study proposes that HAN rather than MIC was most likely the C2H3NO isomer observed in those field studies, although the source chemistry for HAN remains uncharacterized. This study demonstrates the importance of applying absolute calibration standards in the identification and quantification of isomeric compounds. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 1867-1381 1867-8548 |
| Relation: | https://amt.copernicus.org/articles/17/6865/2024/amt-17-6865-2024.pdf; https://doaj.org/toc/1867-1381; https://doaj.org/toc/1867-8548 |
| DOI: | 10.5194/amt-17-6865-2024 |
| URL الوصول: | https://doaj.org/article/68fc7b1c983840a9a714c96b1288ab05 |
| رقم الانضمام: | edsdoj.68fc7b1c983840a9a714c96b1288ab05 |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 18671381 18678548 |
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| DOI: | 10.5194/amt-17-6865-2024 |