Intercomparison of oxygenated volatile organic compound measurements at the SAPHIR atmosphere simulation chamber

Abstract

[1] This paper presents results from the first large-scale in situ intercomparison of oxygenated volatile organic compound (OVOC) measurements. The intercomparison was conducted blind at the large (270 m 3 ) simulation chamber, Simulation of Atmospheric Photochemistry in a Large Reaction Chamber (SAPHIR), in Jülich, Germany. Fifteen analytical instruments, representing a wide range of techniques, were challenged with measuring atmospherically relevant OVOC species and toluene (14 species, C 1 to C 7 ) in the approximate range of 0.5-10 ppbv under three different conditions: (1) OVOCs with no humidity or ozone, (2) OVOCs with humidity added (r.h. % 50%), and (3) OVOCs with ozone (%60 ppbv) and humidity (r.h. % 50%). The SAPHIR chamber proved to be an excellent facility for conducting this experiment. Measurements from individual instruments were compared to mixing ratios calculated from the chamber volume and the known amount of OVOC injected into the chamber. Benzaldehyde and 1-butanol, compounds with the lowest vapor pressure of those studied, presented the most overall difficulty because of a less than quantitative transfer through some of the participants' analytical systems. The performance of each individual instrument is evaluated with respect to reference values in terms of time series and correlation plots for each compound under the three measurement conditions. A few of the instruments performed very well, closely matching the reference values, and all techniques demonstrated the potential for quantitative OVOC measurements. However, this study showed that nonzero offsets are present for specific compounds in a number of instruments and overall improvements are necessary for the majority of the techniques evaluated here.Citation: Apel, E. C., et al. (2008), Intercomparison of oxygenated volatile organic compound measurements at the SAPHIR atmosphere simulation chamber,

Technical Note: Formal blind intercomparison of HO<sub>2</sub> measurements in the atmosphere simulation chamber SAPHIR during the HOxComp campaign

“…These experiments proved that the chamber can serve as a homogeneous source for e.g. OVOCs (Apel et al, 2008), OH (Schlosser et al, 2007(Schlosser et al, , 2009 and NO 2 (Fuchs et al, 2010).…”

Comparison of VOC measurements made by PTR-MS, adsorbent tubes–GC-FID-MS and DNPH derivatization–HPLC during the Sydney Particle Study, 2012: a contribution to the assessment of uncertainty in routine atmospheric VOC measurements

“…Previous published atmospheric and chamber study measurements reported PTR-MS values for acetone that were ∼ 30 to > 100 % higher than simultaneous DNPH-HPLC measurements Apel et al, 2008;Cui et al, 2016). Conversely, generally good agreement has been observed between PTR-MS and GC methods and AP-CIMS (atmospheric pressure chemical ionization mass spectrometry) (slopes = 0.97-1.18, intercept = −0.28-0.06, R 2 = 0.77-0.96) (Fig.…”

“…Previous studies have reported PTR-MS values for formaldehyde that were systematically higher than DNPH-HPLC measurements (Wisthaler et al, 2008;Cui et al, 2016) and higher than differential optical absorption spectroscopy (DOAS) and Hantzsch techniques (Wisthaler et al, 2008;Warneke et al, 2011). Other studies report DNPH-HPLC values for formaldehyde that were systematically lower than those reported by other analytical methods (DOAS, FTIR, Hantzsch, TDLAS) (Kleindienst et al, 1988;Lawson et al, 1990;Gilpin et al, 1997;Hak et al, 2005;Wisthaler et al, 2006).…”

“…In an atmospheric simulation chamber study three PTR-MS instruments reported acetaldehyde values close to the known injected value, whereas a DNPH method significantly underestimated (∼ 30 %) the known chamber concentration (Apel et al, 2008). In a recent comparison in urban air between PTR-MS and DNPH-HPLC, Cui et al (2016) reported a slope of ∼ 1 between the two methods but a significant positive offset in the PTR-MS data of 0.83 ppbv and an R 2 of 0.56.…”

Intercomparison of peroxy radical measurements obtained at atmospheric conditions by laser-induced fluorescence and electron spin resonance spectroscopy

“…It provides a large volume of homogeneously mixed air, to which trace gases can be added at tropospheric concentration levels. For instrumental comparisons, it ensures that the instruments sample air of the same composition and at natural conditions, as was demonstrated for OH (Schlosser et al, 2007) and oxygenated volatile organic compounds (Apel et al, 2008). A further advantage of the use of a chamber is that experiments can be carried out at controlled conditions, allowing, for example, to keep radical concentrations constant at different levels.…”