Proton Transfer Reaction Mass Spectrometry

Methanol emissions from maize: Ontogenetic dependence to varying light conditions and guttation as an additional factor constraining the flux

“…Since air from the compressor had a much lower CO 2 concentration (approx. 200 ppmv) than the ambient air, pure CO 2 from a commercial gas bottle (Air products, 99.5% pure) was added (Lindinger et al, 1998;Ellis and Mayhew, 2014). The PTR-MS was operated at a drift tube pressure of 2.1 hPa, a drift tube temperature of 60 C and a drift tube voltage of 600 V, resulting in a value for E/N (ratio of the electric field E to the gas number density N) in the drift tube of 130 Td (1 Td ¼ 10 À17 V cm 2 ).…”

Selective reagent ion-time of flight-mass spectrometry study of six common monoterpenes

“…On the other hand, direct injection mass spectrometry with CI is a way of ionizing species for separation and analysis by mass spectrometry and it is suitable for real time analysis. Here, the most commonly used techniques are: Proton Transfer Reaction Mass Spectrometry (PTR-MS) [10,11] and Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) [12].…”

“…Chemical ionization utilizes charged molecules such as H 3 O + , NO + and O 2 + as a means of ionization, rather than conventional 70 V electron impact ionization, resulting in overall lower fragmentation of the compounds [11]. In this way CI based instruments may achieve good sensitivity in real time, but with less compound selectivity.…”

Polyphenols and aromatic volatile compounds in biodynamic and conventional ‘Golden Delicious’ apples (Malus domestica Bork.)

“…The measurement of VOCs emitted by different samples was performed with a PTR-TOF 8000 instrument (Ionicon Analytik GmbH Innsbruck, Austria) using H 3 O + as reagent ion for the proton transfer reaction (see Ellis and Mayhew [22] for an in-depth description of the technology). Measurements were performed at controlled temperature (20 ± 3 °C) and humidity (65%) to avoid any interference on VOCs emission and detection by such parameters [21].…”