Monitoring the formation of N-nitrosamines in lyocell plants-pitfalls and solutions

• Published in: Cellulose (London) Vol. 31; no. 18; pp. 11211 - 11224
• Main Authors: Schoenauer, Sebastian, Hager, Christian, Punz, Manuel, Milacher, Walter, Fuchs, Heidrun, Roeder, Thomas, Rosenau, Thomas, Eisenbrand, Gerhard
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.12.2024; Springer Nature B.V
• Subjects: adsorption; Age groups; air; Air sampling; Amines; Bioorganic Chemistry; Cartridges; Cellulose; Cellulose fibers; Ceramics; Chemistry; Chemistry and Materials Science; Chromatography; Composites; Cosmetics; Dilution; Food; Gas chromatography; Glass; Glass fibers; Hazardous materials; isotope dilution technique; Mass spectrometry; morpholine; Natural Materials; Nitrogen oxides; nitrosamines; Organic Chemistry; Original Research; Phosphoric acid; Physical Chemistry; Polymer Sciences; Risk assessment; Scientific imaging; solvents; stable isotopes; Sulfamic acid; Sustainable Development; Tobacco smoke; Trapping; nitroso; nitrosation; Air sampling; methylmorpholine; Occupational atmosphere; methylethanolamine; Artifact; 2,3-Dehydro
• ISSN: 0969-0239; 1572-882X
• DOI: 10.1007/s10570-024-06253-5

In the lyocell process N -methylmorpholine N -oxide (NMMO) is used as a solvent to produce cellulosic fibers. During the process, NMMO degrades to a very low extent into amines, such as morpholine, which may be subject to N -nitrosation to generate traces of N -nitrosomorpholine (NMOR), if conditions prevail favoring this reaction. In addition to NMOR, trace amounts of N -nitroso- N -methylethanolamine (NNMEA) were identified in the ambient air around the spinning site using commercially available air sampling cartridges, analysis by gas chromatography coupled to mass spectrometry (GC–MS), and quantitation by a stable isotope dilution assay (SIDA). N -Nitrosamines present in ambient air are trapped on the cartridge’s adsorption material containing sulfamic acid to prevent de novo N -nitrosation reactions during trapping. Notwithstanding the presence of a nitrosation inhibitor, on-cartridge formation of NNMEA may occur during sampling at elevated nitrogen oxide (NO x ) concentrations in the sampling atmosphere. This as yet unrecognized problem of artifact formation was solved by insertion of a glass fiber filter impregnated with phosphoric acid in front of the air sampling cartridge. The additional filter warrants artifact-free sampling by trapping the most likely precursor 2,3-dehydro- N -methylmorpholine (DNMM) quantitatively on the glass fiber filter. A plausible mechanism of the reaction sequence leading to the formation of NNMEA is proposed.