| Title: | Nitrogen monoxide as dopant for enhanced selectivity of isomeric monoterpenes in drift tube ion mobility spectrometry with (3)H ionization |
| Author(s): | Brendel R; Rohn S; Weller P; |
| Address: | "Institute for Instrumental Analytics and Bioanalytics, Mannheim University of Applied Sciences, Paul-Wittsack-Strasse 10, 68163, Mannheim, Germany. Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany. Department of Food Chemistry and Analysis, Institute of Food Technology and Food Chemistry, Technische Universitat Berlin, TIB 4/3-1, Gustav-Meyer-Allee 25, 13355, Berlin, Germany. Institute for Instrumental Analytics and Bioanalytics, Mannheim University of Applied Sciences, Paul-Wittsack-Strasse 10, 68163, Mannheim, Germany. p.weller@hs-mannheim.de" |
| DOI: | 10.1007/s00216-021-03306-7 |
| ISSN/ISBN: | 1618-2650 (Electronic) 1618-2642 (Print) 1618-2642 (Linking) |
| Abstract: | "The ion mobility spectra of the isomeric monoterpenes alpha-pinene, beta-pinene, myrcene, and limonene in drift tube ion mobility spectrometry (IMS) with (3)H radioactive ionization are highly similar and difficult to distinguish. The aim of this work was to enhance the selectivity of IMS by the addition of nitrogen monoxide (NO) as dopant and to investigate the underlying changes in ion formation responsible for the modified ion signals observed in the ion mobility spectra. Even though (3)H-based-IMS systems have been used in hyphenation with gas chromatography (GC) for profiling of volatile organic compounds (VOCs), the investigation of ion formation still remains challenging and was exemplified by the investigated monoterpenes. Nonetheless, the formation of monomeric, dimeric, and trimeric ion clusters could be tentatively confirmed by a mass-to-mobility correlation and the highly similar pattern of ion signals in the monomer region was attributed to isomerization mechanisms potentially occurring after proton transfer reactions. The addition of NO as dopant could finally lead to the formation of additional product ions and increased the selectivity of IMS for the investigated monoterpenes as confirmed by principal component analysis (PCA). The discrimination of monoterpenes in the volatile profile is highly relevant in the quality control of hops and was given as the example for application. The results indicate that additional product ions were obtained by the formation of NO(+) adduct ions, next to hydride abstraction, charge transfer, or fragmentation reactions. This approach can potentially leverage selectivity issues in VOC profiling of complex matrices, such as food matrices or raw materials in combination with chemometric pattern recognition techniques" |
| Keywords: | Dopant Ion formation Ion mobility spectrometry Radioactive ionization Terpenes; |
| Notes: | "PubMed-not-MEDLINEBrendel, Rebecca Rohn, Sascha Weller, Philipp eng FH Impuls / M2Aind/Bundesministerium fur Bildung und Forschung/ Germany 2021/04/12 Anal Bioanal Chem. 2021 May; 413(13):3551-3560. doi: 10.1007/s00216-021-03306-7. Epub 2021 Apr 10" |
