%0 Journal Article %1 Timko:2009p1836 %A Timko, Michael T %A Yu, Zhenhong %A Kroll, Jesse H %A Jayne, John T %A Worsnop, Douglas R %A Miake-Lye, Richard C %A Onasch, Timothy B %A Liscinsky, David %A Kirchstetter, Thomas W %A Destaillats, Hugo %A Holder, Amara L %A Smith, Jared D %A Wilson, Kevin R %D 2009 %J Aerosol Science and Technology %K Aerosol Mass-Spectrometer, Particles %N 9 %P 855--865 %R 10.1080/02786820902984811 %T Sampling Artifacts from Conductive Silicone Tubing %V 43 %X We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: (1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and (2) silicone tubing emits organic contaminants containing siloxane that are adsorbed onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and the tubing should, therefore, be used with caution. Contamination associated with the use of silicone tubing was observed at ambient temperature and, in some cases, was enhanced by mild heating (<70 degrees C) or pre-exposure to a solvent (methanol). Further evaluation is warranted to quantify systematically how the contamination responds to variations in system temperature, physicochemical particle properties, exposure to solvent, sample contact time, tubing age, and sample flow rates.

@article{Timko:2009p1836, abstract = {We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: (1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and (2) silicone tubing emits organic contaminants containing siloxane that are adsorbed onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and the tubing should, therefore, be used with caution. Contamination associated with the use of silicone tubing was observed at ambient temperature and, in some cases, was enhanced by mild heating (<70 degrees C) or pre-exposure to a solvent (methanol). Further evaluation is warranted to quantify systematically how the contamination responds to variations in system temperature, physicochemical particle properties, exposure to solvent, sample contact time, tubing age, and sample flow rates.}, added-at = {2010-06-22T19:38:37.000+0200}, affiliation = {Aerodyne Res Inc, Ctr Aerothermodynam, Billerica, MA 01821 USA}, author = {Timko, Michael T and Yu, Zhenhong and Kroll, Jesse H and Jayne, John T and Worsnop, Douglas R and Miake-Lye, Richard C and Onasch, Timothy B and Liscinsky, David and Kirchstetter, Thomas W and Destaillats, Hugo and Holder, Amara L and Smith, Jared D and Wilson, Kevin R}, biburl = {https://www.bibsonomy.org/bibtex/2e7504b75bd7f1d0dfe139e867e3c0845/gsmith}, date-added = {2010-03-11 12:04:12 -0500}, date-modified = {2010-03-11 12:05:01 -0500}, doi = {10.1080/02786820902984811}, interhash = {a8b2221ac786fe2093bc0865bbf00da9}, intrahash = {e7504b75bd7f1d0dfe139e867e3c0845}, journal = {Aerosol Science and Technology}, keywords = {Aerosol Mass-Spectrometer, Particles}, language = {English}, local-url = {file://localhost/Users/geoffreysmith/Documents/Papers/Aerosol%20Science%20and%20Technology/2009/Aerosol%20Science%20and%20Technology,%2043,%20855-865%202009.pdf}, month = Jan, number = 9, pages = {855--865}, pmid = {000267821600001}, rating = {0}, timestamp = {2010-06-22T19:39:10.000+0200}, title = {Sampling Artifacts from Conductive Silicone Tubing}, uri = {papers://E88B624E-D406-46FF-9D95-BB9C1AAE3FDC/Paper/p1836}, volume = 43, year = 2009 }