SUPPORTING INFORMATION
APPLICATION OF PROTON-TRANSFER-REACTION-MASS-SPECTROMETRY (PTR-MS)
FOR INDOOR AIR QUALITY RESEARCH
Tobias Schripp1, Sebastian Etienne1, Christian Fauck1, Frank Fuhrmann1, Lukas Märk2,
Tunga Salthammer1
1
Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry
Bienroder Weg 54E, 38108 Braunschweig, Germany
2
IONICON Analytik GmbH
Eduard-Bodem-Gasse 3, 6020 Innsbruck, Austria
PTR instruments in atmospheric sciences
Due to the diversity of PTR technology there are various approaches for PTR-MS and PTRTOF systems. In some cases the inlet has been designed to analyze airborne particles in a
multistep sampling and thermal desorption process (Winkler et al., 2013). The formation of
proton ions may be performed by using a hallow cathode (Ennis et al., 2005), a direct current
discharge source (Inomata et al., 2006), a radioactive source (Blake et al., 2004) or an ion
funnel (Barber et al., 2012). With regard to the mass-filter the common quadrupol filter
(Lindinger et al., 1998), an ion trap (Prazeller et al., 2003), a linear ion trap (Mielke et al.,
2008) and a time-of-flight filter (Tanimoto et al., 2007) are used. The size of the components
is also an important factor if the system is applied in flight (Wisthaler et al., 2013).
Most of these instruments are not commercially available but are modifications of available
instruments or self-developed systems.
Barber, S., Blake, R.S., White, I.R., Monks, P.S., Reich, F., Mullock, S., Ellis, A.M. (2012)
Increased Sensitivity in Proton Transfer Reaction Mass Spectrometry by
Incorporation of a Radio Frequency Ion Funnel, Analytical Chemistry, 84, 5387−5391.
Blake, R.S., Whyte, C., Hughes, C.O., Ellis, A.M. and Monks, P.S. (2004) "Demonstration of
proton-transfer reaction time-of-flight mass spectrometry for real-time analysis of
trace volatile organic compounds", Analytical Chemistry, 76, 3841-3845.
Ennis, C.J., Reynolds, J.C., Keely, B.J. and Carpenter, L.J. (2005) "A hollow cathode proton
transfer reaction time of flight mass spectrometer", International Journal of Mass
Spectrometry, 247, 72-80.
Inomata, S., Tanimoto, H., Aoki, N., Hirokawa, J. and Sadanaga, Y. (2006) "A novel
discharge source of hydronium ions for proton transfer reaction ionization: design,
characterization, and performance", Rapid Communications in Mass Spectrometry,
20, 1025-1029.
Jordan, A., Haidacher, S., Hanel, G., Hartungen, E., Märk, L., Seehauser, H., Schottkowsky,
R., Sulzer, P., Märk, T.D. (2009) “A high resolution and high sensitivity proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS)”, International Journal of
Mass Spectrometry, 286, 122-128.
Lindinger, W., Hansel, A. and Jordan, A. (1998) "On-line monitoring of volatile organic
compounds at pptv levels by means of proton-transfer-reaction mass spectrometry
(PTR-MS) medical applications, food control and environmental research",
International Journal of Mass Spectrometry and Ion Processes, 173, 191-241.
Mielke, L.H., Erickson, D.E., McLuckey, S.A., Müller, M., Wisthaler, A., Hansel, A. and
Shepson, P.B. (2008) "Development of a Proton-Transfer Reaction-Linear Ion Trap
Mass Spectrometer for Quantitative Determination of Volatile Organic Compounds",
Analytical Chemistry, 80, 8171-8177.
Prazeller, P., Palmer, P.T., Boscaini, E., Jobson, T. and Alexander, M. (2003) "Proton
transfer reaction ion trap mass spectrometer", Rapid Communications in Mass
Spectrometry, 17, 1593-1599.
Tanimoto, H., Aoki, N., Inomata, S., Hirokawa, J. and Sadanaga, Y. (2007) "Development of
a PTR-TOFMS instrument for real-time measurements of volatile organic compounds
in air", International Journal of Mass Spectrometry, 263, 1-11.
Winkler, P.M., Lawler, M. and Smith, J.N. (2013) Size-resolved chemical characterization of
biogenic nanoparticles by thermal desorption chemical ionization mass spectrometry,
In: Hansel, A. and Dunkl, J. (eds) 6th International Conference on Proton Transfer
Reaction Mass Spectrometry and its Applications, Obergurgl, Austria, Innsbruck
University Press, 92-95.
Wisthaler, A., Crawford, J.H., Haidacher, S., Hanel, G., Hartungen, E., Jordan, A., Märk, L.,
Mikoviny, T., Müller, M., Mutschlechner, P., Schottkowsky, R. and Sulzer, P. (2013)
Development of a compact PTR-TOF-MS for Suborbital Research on the Earth's
Atmospheric Composition, In: Hansel, A. and Dunkl, J. (eds) 6th International
Conference on Proton Transfer Reaction Mass Spectrometry and its Applications,
Obergurgl, Austria, Innsbruck University Press, 96.
Additional Figures and Tables
Normed Transmission
2.0
1.5
1.0
0.5
TOF-Transmission (actual)
TOF-Transmission (ideal)
Transmission curve (actual)
Transmission curve (ideal)
0.0
0
200
400
600
800
1000
m/z
Figure S1: Transmission curve of the applied PTR-TOF instrument in comparison to the
expected transmission curve of a reference instrument (source: Ionicon).
Table S1: Fitting parameters for a non-linear regression of the TEA-concentrations from
Figure 3 using equation (S1). The exponential factors are given in bold.
Paint 1
Paint 2
Paint 3
Paint 4
a
10.70
16.06
8.78
9.80
b
1.39
2.76
0.78
0.88
c
16.74
13.10
8.24
3.83
d
0.13
0.13
0.08
0.03
R
0.9998
0.9987
0.9966
0.9924
𝑐(𝑡) = 𝑎 ∙ (1 − 𝑒 −𝑏∙𝑡 ) + 𝑐 ∙ (1 − 𝑒 −𝑑∙𝑡 )
(S1)
Counts (m/z x / m/z 21)
0.1
0.1
n-Pentanal (m)
0.1
Isobutyric acid (m)
0.1
0.01
0.01
0.01
0.01
0.001
0.001
56.6
56.8
0.1
Counts (m/z x / m/z 21)
Acetic acid (m)
n-Octanol (f)?
57.0
57.2
Hexanoic acid (f)
0.001
60.6
57.4
0.1
60.8
61.0
61.2
61.4
n-Hexanal (f)
0.001
86.6
0.1
86.8
87.0
87.2
87.4
Heptanoic acid (m)
88.6
0.1
0.01
0.01
0.01
0.01
0.001
0.001
0.001
0.001
98.6
98.8
99.0
99.2
99.4
100.6 100.8 101.0 101.2 101.4
130.6 130.8 131.0 131.2 131.4
Figure S2: Enlarged display of selected signals in Figure 7 for the PTR-QMS (red bar) and PTR-TOF (black line).
88.8
89.0
89.2
89.4
3-Caren (m)
a-Pinen (m)
136.6 136.8 137.0 137.2 137.4