Atmospheric Measurement Techniques Discussions www.atmos-meas-tech-discuss.net 1867-8610 2 2 2009 10.5194/amtd-2-893-2009 http://www.atmos-meas-tech-discuss.net/2/893/2009/ http://www.atmos-meas-tech-discuss.net/2/893/2009/amtd-2-893-2009.html http://www.atmos-meas-tech-discuss.net/2/893/2009/amtd-2-893-2009.pdf 893 914 2009-03-23 Design and construction of a simple Knudsen Effusion Mass Spectrometer (KEMS) system for vapour pressure measurements of low volatility organics A. M. Booth alastair.booth@manchester.ac.uk T. Markus G. McFiggans C. J. Percival M. R. Mcgillen D. O. Topping School of Earth, Environmental and Atmospheric Science, University of Manchester, UK Research Center Jülich, Germany A design of and initial results from a Knudsen Effusion Mass Spectrometer (KEMS) are presented. The design was adapted from high temperature alloy studies with a view to using it to measure vapour pressures for low volatility organics. The system uses a temperature controlled cell with an effusive orifice. This produces a molecular beam which is sampled by a quadropole mass spectrometer with electron impact ionization calibrated to a known vapour pressure. We have determined P298 and ΔHsub of the first 5 unsaturated straight chain dicarboxylic acids: 2.15±1.19×10−2 Pa and 75±19 kJ mol−1 respectively for Oxalic acid, 5.15±0.76×10−4 Pa and 91±4 kJ mol−1 for Malonic acid, 9.19±2.26×10−5 Pa and 93±6 kJ mol−1 for Succinic acid, 4.21±1.66×10−4 Pa and 123±22 kJ mol−1 for Glutaric acid and 5.21±3.84×10−6 Pa and 125±40 kJ mol−1 for Adipic acid. Benczk, L., Markus, T., Dash, S., Raj, D. D., Kath, D., Oates, W. A., Loser, W., and Hilpert, K.: Thermodynamic Properties of B2-AlFeNi Alloys. Part 1: Investigation by Knudsen Effusion Mass Spectrometry, Metallurgical and Material Transactions A, 37A, 3171–3181, 2006. Bilde, M. and Pandis, S.: Evaporation Rates and Vapor Pressures of Individual Aerosol Species Formed in the Atmospheric Oxidation of alpha- and beta-Pinene, Environ. Sci. Technol., 35, 3344–3349, 2001. Bilde, M., Svenningsson, B., Monster, J., and Rosenorn, T.: Even - Odd Alternation of Evaporation Rates and Vapor Pressures of C3 - C9 Dicarboxylic Acid Aerosols, Environ. Sci. Technol., 37, 1371–1378, 2003. Cappa, C., Lovejoy, E., and Ravishankara, A.: Determination of Evaporation Rates and Vapor Pressures of Very Low Volatility Compounds: A Study of the C4-C10 and C12 Dicarboxylic Acids, J. Phys. Chem. A, 111, 3099–3109, 2007. Ekeren, P. v., Jacobs, M., Offringa, J., and Kruif, C. G. D.: Vapour-pressure measurements on trans-diphenylethene and naphthalene using a spinning-rotor friction gauge, J. Chem. Thermodyn., 15, 409–417, 1982. Hastie, J.: New techniques and opportunities in high temperature mass spectrometry, Pure Appl.Chem., 56, 1583–1600, 1984. Hilpert, K.: High-temperature Mass Spectrometry in Materials Research, Rapid Commun. Mass Sp., 5, 175–187, 1991. Hilpert, K.: Potential of mass spectrometry for the analysis of inorganic high-temperature vapors, Fresen. J. Anal. Chem., 370, 471–478, 2001. Hilpert, K. and Miller, M.: Determination of the thermodynamic activities of NaBr and DyBr3 in the phases of the NaBr-DyBr3 system at 863 K by Knudsen effusion mass spectrometry, J. Alloy. Compd., 379, 1–7, 2004. Jacobs, M., Ekeren, P. v., and Kruif, C. G. D.: The vapour pressure and enthalpy of sublimation of ferrocence, J. Chem. Thermodyn., 15, 619–623, 1983. Johnson, D., Jenkin, M. E., Wirtz, K., and Martin-Reviejo, M.: Simulating the Formation of Seconday Organic Aersol from the Photooxidation of Aromatic Hydrocarbons, Environ. Chem., 2, 35–48, 2005. Johnson, D., Utembe, S. R., and Jenkin, M. E.: Simulating the detailed chemical composition of secondary organic aerosol formed on a regional scale during the TORCH 2003 campaign in the southern UK, Atmos. Chem. Phys., 6, 419–431, 2006. Kruif, C. G. D., Miltenburg, J. C. V., and Blok, J.: Molar heat capacities and vapour pressures of solid and liquid benzophenone, J. Chem. Thermodyn., 15, 129–136, 1983. Shilov, A. L., Holappa, L. E., and Stolyarova, V. L.: A Knudsen Effusion High Temperature Assembly for a Quadrupole QMG-420 Mass Spectrometer, Rapid Commun. Mass Sp., 11, 1425–1429, 1997. Silva, M. R. D., Monte, M., and Ribeiro, J.: Vapour pressures and the enthalpies and entropies of sublimation of five dicarboxylic acids, J. Chem. Thermodyn., 31, 1093–1107, 1999. Silva, M. R. D., Monte, M., and Ribeiro, J.: Thermodynamic study on the sublimation of succinic acid and of methyl- and dimethyl-substituted succinic and glutaric acids, J. Chem. Thermodyn., 33, 23–31, 2001. Tao, Y. and McMurry, P.: Vapor Pressures and Surface Free Energies of C14-C18 Monocarboxylic Acids and C5 and C6 Dicarboxylic Acids, Environ. Sci. Technol., 23, 1519–1523, 1989. Wit, H. G. M. d., Bouwstra, J. A., Blok, J. G., and Kruif, C. G. D.: Vapor pressures and lattice energies of oxalic acid, mesotartaric acid, phloroglucinol, myoinositol, and their hydrates, J. Chem. Phys., 78, 1470–1475, 1982.