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Hu J, Chen C, Zhou H, Zhang L, Yan S, Liang H. Investigation of unexpected silane ions caused by gas-phase reactions in Orbitrap gas chromatography-mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9740. [PMID: 38567573 DOI: 10.1002/rcm.9740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/04/2024] [Accepted: 02/27/2024] [Indexed: 04/04/2024]
Abstract
RATIONALE The mass spectra of compounds containing dimethyl (phenyl)silyl group (-SiMe2Ph) sometimes exhibit unusual ion peaks when measured using Orbitrap gas chromatography-mass spectrometry (GC-MS). This would complicate the mass spectra and may limit the matching of spectral data with preexisting resources for compound annotation. These peaks were identified as products from reactions with residual water. METHODS A series of dimethyl (phenyl)silyl compounds were dissolved in methanol and investigated using Orbitrap GC-MS. Certain ions reacted with residual water in the C-trap. The reaction was confirmed using accurate mass and elemental composition analysis via MS studies, and the active center of the reaction was determined using density functional theory (DFT) calculations. RESULTS Two types of gas-phase reactions between gaseous water and cations from a series of silanes were identified. DFT calculations indicate that silicon (Si) acts as the active center for these gas-phase water reactions. Compounds with multiple Si atoms generate a larger number of additional ions, which would complicate the mass spectra. The mass spectra of vinylsilanes and alkylsilanes with -SiMe2Ph indicate that the conjugated group linked to -SiMe2Ph can affect the water adduction process. CONCLUSIONS Silane ions could react with residual water in the C-trap of an Orbitrap mass spectrometer. The mass spectra of these compounds may exhibit unexplained peaks arising from gas-phase reactions. Although these reactions may decrease spectral matching scores for compound annotation, they offer opportunities for systematic investigations into the mechanistic and kinetic aspects of high-energy ion reactivity.
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Affiliation(s)
- Jingxin Hu
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, China
| | - Chunying Chen
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
| | - Haiyun Zhou
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, China
| | - Li Zhang
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
| | - Sujun Yan
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, China
| | - Hui Liang
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
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Nishiyama Y, Kumagai S, Kameda T, Saito Y, Watanabe A, Watanabe C, Teramae N, Yoshioka T. Direct Gas-Phase Derivatization by Employing Tandem μ-Reactor-Gas Chromatography/Mass Spectrometry: Case Study of Trifluoroacetylation of 4,4'-Methylenedianiline. Anal Chem 2020; 92:14924-14929. [PMID: 32964712 DOI: 10.1021/acs.analchem.0c01830] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) is a promising technique allowing the rapid characterization of the polymer structure and additives of microgram-scale plastics. However, the Py-GC/MS analysis of polymers with urethane bonds is challenging because they produce highly reactive pyrolyzates such as amines and isocyanates polymerizing in the GC column, which limits the efforts to elucidate the pyrolysis mechanism and plastic characterization by online GC analysis. Herein, a novel pyrolysis-gas-phase derivatization-GC/MS (Py-GPD-GC/MS) technique was developed, allowing the pyrolysis of polymers and the subsequent direct gas-phase derivatization of pyrolyzates, employing a modified tandem μ-reactor-GC/MS system. This work conducted the gas-phase trifluoroacetylation of 4,4'-methylenedianiline (MDA), which is one of the major polyurethane (PU) pyrolyzates, using N-methyl-bis-trifluoroacetamide (MBTFA) as a derivatization agent. The trifluoroacetylation gas-phase reaction was monitored by in situ GC/MS analysis and the effects of derivatization conditions were investigated. The highest MDA conversion observed was 65.6 area %. Furthermore, the sequential PU pyrolysis and direct trifluoroacetylation of PU pyrolyzates in the first μ-reactor and second μ-reactor, respectively, were successfully operated, achieving the inhibited polymerization and detection of trifluoroacetylated derivatives. Thus, the Py-GPD-GC/MS method has a significant potential to be applied for other combinations of pyrolyzates and derivatization reactions, enabling deeper characterization of plastics producing highly reactive pyrolyzates that cannot be accurately analyzed by conventional Py-GC/MS analysis.
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Affiliation(s)
- Yuya Nishiyama
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Shogo Kumagai
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Tomohito Kameda
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Yuko Saito
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Atsushi Watanabe
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan.,Frontier Laboratories Ltd., 4-16-20, Saikon, Koriyama, Fukushima 963-8862, Japan
| | - Chuichi Watanabe
- Frontier Laboratories Ltd., 4-16-20, Saikon, Koriyama, Fukushima 963-8862, Japan
| | - Norio Teramae
- Frontier Laboratories Ltd., 4-16-20, Saikon, Koriyama, Fukushima 963-8862, Japan.,Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Toshiaki Yoshioka
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan
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Kumagai S, Asakawa M, Kameda T, Saito Y, Watanabe A, Watanabe C, Teramae N, Yoshioka T. Hydrogen and steam injected tandem μ-reactor GC/FID system: phenol recovery from bisphenol A and alkylphenols using Ni/Y zeolite. REACT CHEM ENG 2019. [DOI: 10.1039/c9re00299e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Hydrogen and steam injected tandem μ-reactor-GC/FID system achieved online quantification of products from hydrogenation and dealkylation of bisphenol A and alkylphenols using Ni/Y zeolite.
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Affiliation(s)
- S. Kumagai
- Graduate School of Environmental Studies
- Tohoku University
- Sendai
- Japan
| | - M. Asakawa
- Graduate School of Environmental Studies
- Tohoku University
- Sendai
- Japan
| | - T. Kameda
- Graduate School of Environmental Studies
- Tohoku University
- Sendai
- Japan
| | - Y. Saito
- Graduate School of Environmental Studies
- Tohoku University
- Sendai
- Japan
| | | | | | - N. Teramae
- Frontier Laboratories Ltd
- Koriyama
- Japan
- Department of Chemistry
- Graduate School of Science
| | - T. Yoshioka
- Graduate School of Environmental Studies
- Tohoku University
- Sendai
- Japan
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