[Schmidberger2013]
Schmidberger, T.., R.. Gutmann, and R.. Huber,
"Application of PTR-MS in mammalian cell culture",
6th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 39, 2013.
Link:
http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_6.pdf
Mass spectrometry is a well-known technology to detect O2 and CO2 in the off-gas of cell culture fermentations. In contrast to classical spectrometers, the proton transfer reaction mass spectrometer (PTR-MS) applies a very soft ionization strategy and therefore the spectra show less fragments and are easier to interpret. In our study we applied the PTR-MS technology to monitor volatile organic compounds (VOC) in mammalian cell culture processes. Interesting masses were identified and correlations between PTR-MS data and off-line parameters will be presented.
[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.
Link:
http://dx.doi.org/10.1088/1752-7155/7/1/017110
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.
[Kohl2013a]
Kohl, I., J. Beauchamp, F. Cakar-Beck, J. Herbig, J. Dunkl, O. Tietje, M. Tiefenthaler, C. Boesmueller, A. Wisthaler, M. Breitenlechner, et al.,
"Non-invasive detection of renal function via breath gas analysis: A potential biomarker for organ acceptance?",
6th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 24, 2013.
Link:
http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_6.pdf
Breath gas analysis is an emerging field that attempts to link components in exhaled breath gas with state-of-health or illness [1]. This is based on the premise that disease in the body will elicit abnormal biochemical reactions which in turn produce chemical compounds that might be excreted by the body - at least in part - via exhalation. We used PTR-MS to directly sample and analyse selected VOC constituents in the exhaled breath of patients (n=96) undergoing kidney transplantation. Breath samples were taken before surgery and then over an extended period thereafter. Comparison of PTR-MS data with routine blood-serum data revealed a specific compound (ion trace) at m/z 115 that correlated with creatinine in blood serum and daily urine production, which are the current generally-accepted markers for kidney function. PTR-TOF analyses revealed that this compound had an exact molecular mass of 114.104 u and a chemical composition of C7H14O. Subsequent analyses using PTR-QqQ-MS suggested the compound to be a C7-ketone or branched C7-aldehyde. It is hoped that the results of this study will provide impetus to other researchers in the field to further delve into the nature of this compound and its possible biochemical production routes to ascertain the eligibility of this compound for potential use in future routine breath analysis for renal function assessment.