Direct Gas-Phase Derivatization by Employing Tandem μ-Reactor-Gas Chromatography/Mass Spectrometry: Case Study of Trifluoroacetylation of 4,4′-Methylenedianiline

Yuya Nishiyama, Shogo Kumagai, Tomohito Kameda, Yuko Saito, Atsushi Watanabe, Chuichi Watanabe, Norio Teramae, Toshiaki Yoshioka

Research output: Contribution to journalArticlepeer-review

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.

Original languageEnglish
Pages (from-to)14924-14929
Number of pages6
JournalAnalytical Chemistry
Volume92
Issue number22
DOIs
Publication statusPublished - 2020 Nov 17

ASJC Scopus subject areas

  • Analytical Chemistry

Fingerprint Dive into the research topics of 'Direct Gas-Phase Derivatization by Employing Tandem μ-Reactor-Gas Chromatography/Mass Spectrometry: Case Study of Trifluoroacetylation of 4,4′-Methylenedianiline'. Together they form a unique fingerprint.

Cite this