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Scientific Articles - PTR-MS Bibliography

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Found 6 results
Title [ Year(Asc)]
Filters: Author is Gutmann, Rene  [Clear All Filters]
[1478] Schmidberger, T., R. Gutmann, K. Bayer, J. Kronthaler, and R. Huber, "Advanced online monitoring of cell culture off-gas using proton transfer reaction mass spectrometry", Biotechnology Progress, pp. n/a–n/a, 2014.
<p>Mass spectrometry has been frequently applied to monitor the O2 and CO2 content in the off-gas of animal cell culture fermentations. In contrast to classical mass spectrometry the proton transfer reaction mass spectrometry (PTR-MS) provides additional information of volatile organic compounds by application of a soft ionization technology. Hence, the spectra show less fragments and can more accurately assigned to particular compounds. In order to discriminate between compounds of non-metabolic and metabolic origin cell free experiments and fed-batch cultivations with a recombinant CHO cell line were conducted. As a result, in total eight volatiles showing high relevance to individual cultivation or cultivation conditions could be identified. Among the detected compounds methanethiol, with a mass-to-charge ratio of 49, qualifies as a key candidate in process monitoring due to its strong connectivity to lactate formation. Moreover, the versatile and complex data sets acquired by PTR MS provide a valuable resource for statistical modeling to predict non direct measurable parameters. Hence, partial least square regression was applied to the complete spectra of volatiles measured and important cell culture parameters such as viable cell density estimated (R2&thinsp;=&thinsp;0.86). As a whole, the results of this study clearly show that PTR-MS provides a powerful tool to improve bioprocess-monitoring for mammalian cell culture. Thus, specific volatiles emitted by cells and measured online by the PTR-MS and complex variables gained through statistical modeling will contribute to a deeper process understanding in the future and open promising perspectives to bioprocess control. &copy; 2014 American Institute of Chemical Engineers Biotechnol. Prog., 2014</p>
[Kohl2013b] Kohl, I., J. Beauchamp, F. Cakar-Beck, J. Herbig, J.. Dunkl, O. Tietje, M. Tiefenthaler, C. Boesmueller, A. Wisthaler, M. Breitenlechner, et al., "First observation of a potential non-invasive breath gas biomarker for kidney function.", J Breath Res, vol. 7, no. 1: Ionimed Analytik GmbH, Eduard Bodem Gasse 3, A-6020 Innsbruck, Austria., pp. 017110, Mar, 2013.
We report on the search for low molecular weight molecules-possibly accumulated in the bloodstream and body-in the exhaled breath of uremic patients with kidney malfunction. We performed non-invasive analysis of the breath gas of 96 patients shortly before and several times after kidney transplantation using proton-transfer-reaction mass spectrometry (PTR-MS), a very sensitive technique for detecting trace amounts of volatile organic compounds. A total of 642 individual breath analyses which included at least 41 different chemical components were carried out. Correlation analysis revealed one particular breath component with a molecular mass of 114 u (unified atomic mass units) that clearly correlated with blood serum creatinine, which is the currently accepted marker for assessing the function of the kidney. In particular, daily urine production showed good correlation with the identified breath marker. An independent set of seven samples taken from three patients at the onset of dialysis and three controls with normal kidney function confirmed a significant difference in concentration between patients and controls for a compound with a molecular mass of 114.1035 u using high mass resolving proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOF-MS). A chemical composition of CHO was derived for the respective component. Fragmentation experiments on the same samples using proton-transfer-reaction triple-quadrupole tandem mass spectrometry (PTR-QqQ-MS) suggested that this breath marker is a C-ketone or a branched C-aldehyde. Non-invasive real-time monitoring of the kidney function via this breath marker could be a possible future procedure in the clinical setting.
[Fischer2013a] Fischer, L., A. Klinger, J. Herbig, K. Winkler, R. Gutmann, and A. Hansel, "The LCU: Versatile Trace Gas Calibration", 6th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 192, 2013.
[Fischer2013] Fischer, L., V. Ruzsanyi, K. Winkler, R. Gutmann, A. Hansel, and J. Herbig, "Micro-Capillary-Column PTR-TOF", 6th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 162, 2013.
[Luchner2012] Luchner, M., R. Gutmann, K. Bayer, J. Dunkl, A. Hansel, J. Herbig, W. Singer, F. Strobl, K. Winkler, and G. Striedner, "Implementation of proton transfer reaction-mass spectrometry (PTR-MS) for advanced bioprocess monitoring.", Biotechnol Bioeng, vol. 109, no. 12: ACIB GmbH, Muthgasse 11, A-1190 Vienna, Austria., pp. 3059–3069, Dec, 2012.
We report on the implementation of proton transfer reaction-mass spectrometry (PTR-MS) technology for on-line monitoring of volatile organic compounds (VOCs) in the off-gas of bioreactors. The main part of the work was focused on the development of an interface between the bioreactor and an analyzer suitable for continuous sampling of VOCs emanating from the bioprocess. The permanently heated sampling line with an inert surface avoids condensation and interaction of volatiles during transfer to the PTR-MS. The interface is equipped with a sterile sinter filter unit directly connected to the bioreactor headspace, a condensate trap, and a series of valves allowing for dilution of the headspace gas, in-process calibration, and multiport operation. To assess the aptitude of the entire system, a case study was conducted comprising three identical cultivations with a recombinant E. coli strain, and the volatiles produced in the course of the experiments were monitored with the PTR-MS. The high reproducibility of the measurements proved that the established sampling interface allows for reproducible transfer of volatiles from the headspace to the PTR-MS analyzer. The set of volatile compounds monitored comprises metabolites of different pathways with diverse functions in cell physiology but also volatiles from the process matrix. The trends of individual compounds showed diverse patterns. The recorded signal levels covered a dynamic range of more than five orders of magnitude. It was possible to assign specific volatile compounds to distinctive events in the bioprocess. The presented results clearly show that PTR-MS was successfully implemented as a powerful bioprocess-monitoring tool and that access to volatiles emitted by the cells opens promising perspectives in terms of advanced process control.
[Singer2011] Singer, W., J. Herbig, R. Gutmann, K. Winkler, I. Kohl, and A. Hansel, "Applications of PTR-MS in medicine and biotechnology", American Laboratory, vol. 43, no. 7: AMER LABORATORY-LABCOMPARE 30 CONTROLS DRIVE, SHELTON, CT 06484 USA, pp. 34–37, 2011.
Proton transfer reaction-mass spectrometry (PTR-MS) is a well-established analytical tool for the measurement of volatile organic compounds (VOCs), and offers real-time detection and quantification of VOCs at trace concentrations. This paper focuses on the measurement of VOCs in biological systems. Both microorganisms and cells, e.g., in the human body, constantly produce a large variety of volatile organic metabolites. Analyzing VOCs in exhaled human breath reveals information about the status of the body. In a similar manner, monitoring the off-gas of fermentations in the biopharmaceutical industry allows microbial activity to be gauged. Undesired compounds (those that are harmful to the human body or impurities in biotechnical processes) can also be tracked in real time using the technique.

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Selected PTR-MS related Reviews

F. Biasioli, C. Yeretzian, F. Gasperi, T. D. Märk: PTR-MS monitoring of VOCs and BVOCs in food science and technology, Trends in Analytical Chemistry 30 (7) (2011).

J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, R. Fall: Measurement of Volatile Organic Compounds in the Earth's Atmosphere using Proton-Transfer-Reaction Mass Spectrometry. Mass Spectrometry Reviews, 26 (2007), 223-257.

W. Lindinger, A. Hansel, A. Jordan: Proton-transfer-reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev. 27 (1998), 347-375.


Lists with PTR-MS relevant publications of the University of Innsbruck can be found here: Atmospheric and indoor air chemistry, IMR, Environmental Physics and Nano-Bio-Physics


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