AMT Atmospheric Measurement Techniques AMT Atmos. Meas. Tech. 1867-8548 Copernicus Publications Göttingen, Germany 10.5194/amt-3-1039-2010 A high-resolution mass spectrometer to measure atmospheric ion composition Junninen H. 1 Ehn M. 1 Petäjä T. 1 Luosujärvi L. 2 Kotiaho T. 2 3 Kostiainen R. 3 Rohner U. 4 Gonin M. 4 Fuhrer K. 4 Kulmala M. 1 Worsnop D. R. 1 5 Department of Physics, P.O. Box 64, 00014, University of Helsinki, Helsinki, Finland Department of Chemistry, P.O. Box 55, 00014, University of Helsinki, Helsinki, Finland Division of Pharmaceutical Chemistry, P.O. Box 56, 00014, University of Helsinki, Helsinki, Finland Tofwerk AG, 3600 Thun, Switzerland Aerodyne Research Inc, Billerica, MA 01821, USA 17 08 2010 3 4 1039 1053 Copyright: © 2010 H. Junninen et al. 2010 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://amt.copernicus.org/articles/3/1039/2010/amt-3-1039-2010.html The full text article is available as a PDF file from https://amt.copernicus.org/articles/3/1039/2010/amt-3-1039-2010.pdf

In this paper we present recent achievements on developing and testing a tool to detect the composition of ambient ions in the mass/charge range up to 2000 Th. The instrument is an Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer (APi-TOF, Tofwerk AG). Its mass accuracy is better than 0.002%, and the mass resolving power is 3000 Th/Th. In the data analysis, a new efficient Matlab based set of programs (tofTools) were developed, tested and used. The APi-TOF was tested both in laboratory conditions and applied to outdoor air sampling in Helsinki at the SMEAR III station. Transmission efficiency calibrations showed a throughput of 0.1–0.5% in the range 100–1300 Th for positive ions, and linearity over 3 orders of magnitude in concentration was determined. In the laboratory tests the APi-TOF detected sulphuric acid-ammonia clusters in high concentration from a nebulised sample illustrating the potential of the instrument in revealing the role of sulphuric acid clusters in atmospheric new particle formation. The APi-TOF features a high enough accuracy, resolution and sensitivity for the determination of the composition of atmospheric small ions although the total concentration of those ions is typically only 400–2000 cm<sup>−3</sup>. The atmospheric ions were identified based on their exact masses, utilizing Kendrick analysis and correlograms as well as narrowing down the potential candidates based on their proton affinities as well isotopic patterns. In Helsinki during day-time the main negative ambient small ions were inorganic acids and their clusters. The positive ions were more complex, the main compounds were (poly)alkyl pyridines and – amines. The APi-TOF provides a near universal interface for atmospheric pressure sampling, and this key feature will be utilized in future laboratory and field studies.

 References Arnold,&nbsp;F.: Atmospheric ions and aerosol formation, Space Sci. Rev., 137, 225–239, 2008. Arnold,&nbsp;F.: Multi-Ion complexes in the Stratosphere – implications for trace gases and aerosol, Nature, 284, 610–611, 1980. Asmi, E., Sipilä, M., Manninen, H. E., Vanhanen, J., Lehtipalo, K., Gagné, S., Neitola, K., Mirme, A., Mirme, S., Tamm, E., Uin, J., Komsaare, K., Attoui, M., and Kulmala, M.: Results of the first air ion spectrometer calibration and intercomparison workshop, Atmos. Chem. Phys., 9, 141–154, https://doi.org/10.5194/acp-9-141-2009, 2009. De Gouw,&nbsp;J.&nbsp;A. and Warneke,&nbsp;C.: Measurements of volatile organic compounds in the earth's atmosphere using proton-transfer-reaction mass spectrometry, Mass Spectrom. Rev., 26, 223–257, 2006. DeCarlo,&nbsp;P.&nbsp;F., Kimmel,&nbsp;J.&nbsp;R., Trimborn,&nbsp;A., Northway,&nbsp;M.&nbsp;J., Jayne,&nbsp;J.&nbsp;T., Aiken,&nbsp;A.&nbsp;C., Gonin,&nbsp;M., Fuhrer,&nbsp;K., Horvath,&nbsp;T., Docherty,&nbsp;K.&nbsp;S., Worsnop,&nbsp;D.&nbsp;R., and Jimenez,&nbsp;J.&nbsp;L.: Field-deployable, high-resolution, time-of-flight aerosol mass spectrometer, Anal. Chem., 78, 8281–8289, 2006. Eisele,&nbsp;F.&nbsp;L.: Identification of tropospheric ions,&nbsp;J. Geophys. Res., 91, 7897–7906, 1986. Eisele,&nbsp;F.&nbsp;L.: Natural and anthropogenic negative-ions in the troposphere, J. Geophys. Res.-Atmos., 94, 2183–2196, 1989a. Eisele,&nbsp;F.&nbsp;L.: Natural and transmission-line produced positive-ions, J. Geophys. Res.-Atmos., 94, 6309–6318, 1989b. Fernandez de la Mora,&nbsp;J., Thomson,&nbsp;B.&nbsp;A., and Gamero-Castano,&nbsp;M.: Tandem mobility mass spectrometry study of electrosprayed tetraheptyl ammonium bromide clusters, J. Am. Soc. Mass Spectr., 16, 717–732, 2005. Guilhaus,&nbsp;M., Selby,&nbsp;D., and Mlynski,&nbsp;V.: Orthogonal acceleration time-of-flight mass spectrometry, Mass Spectrom Rev., 19, 65–107, 2000 Haapala,&nbsp;M., Luosujarvi,&nbsp;L., Saarela,&nbsp;V., Kotiaho,&nbsp;T., Ketola,&nbsp;R.&nbsp;A., Franssila,&nbsp;S., and Kostiainen,&nbsp;R.: Microchip for combining gas chromatography or capillary liquid chromatography with atmospheric pressure photoionization-mass spectrometry, Anal. Chem., 79, 4994–4999, 2007. Hanson,&nbsp;D.&nbsp;R. and Eisele,&nbsp;F.&nbsp;L.: Measurement of prenucleation molecular clusters in the NH<sub>3</sub>, H<sub>2</sub>SO<sub>4</sub>, H<sub>2O</sub> system, J. Geophys. Res., 107, 4158, https://doi.org/10.1029/2001JD001100, 2002. Harrison,&nbsp;R.&nbsp;G. and Tammet,&nbsp;H.: Ions in the terrestrial atmosphere and other solar system atmospheres, Space Sci. Rev., 137, 107–118, 2008. Herrmann,&nbsp;W., Eichler,&nbsp;T., Bernardo,&nbsp;N., and Fernandez de la Mora,&nbsp;J.: Turbulent transition arises at Re 35 000 in a&nbsp;short Vienna type DMA with a&nbsp;large laminarizing inlet, Proceedings of the annual conference of the AAAR, St. Louis, MO, 6–10 October 2000. Hirsikko,&nbsp;A., Laakso,&nbsp;L., Hõrrak,&nbsp;U., Aalto,&nbsp;P.&nbsp;P., Kerminen,&nbsp;V.-M., and Kulmala,&nbsp;M.: Annual and size dependent variation of growth rates and ion concentrations in boreal forest, Boreal Environ. Res., 10, 357–369, 2005. Hoffmann,&nbsp;T., O'Dowd,&nbsp;C.&nbsp;D., and Seinfeld,&nbsp;J.&nbsp;H.: Iodine oxide homogeneous nucleation: an explanation for coastal new particle production, Geophys. Res. Lett., 28, 1949–1952, 2001. Huey,&nbsp;L.&nbsp;G.: Measurement of trace atmospheric species by chemical ionization mass spectrometry: Speciation of reactive nitrogen and future directions, Mass. Spectrom. Rev., 26, 166–184, 2007. Hughey,&nbsp;C.&nbsp;A., Hendrickson,&nbsp;C.&nbsp;L., Rodgers,&nbsp;R.&nbsp;P., Marshall,&nbsp;A.&nbsp;G., and Qian,&nbsp;K.&nbsp;N.: Kendrick mass defect spectrum: a&nbsp;compact visual analysis for ultrahigh-resolution broadband mass spectra, Anal. Chem., 73, 4676–4681, 2001. Hussein,&nbsp;T., Dal Maso,&nbsp;M., Petaja,&nbsp;T., Koponen,&nbsp;I.&nbsp;K., Paatero,&nbsp;P., Aalto,&nbsp;P.&nbsp;P., Hameri,&nbsp;K., and Kulmala,&nbsp;M.: Evaluation of an automatic algorithm for fitting the particle number size distributions, Boreal Environ. Res., 10, 337–355, 2005. Iida,&nbsp;K., Stolzenburg,&nbsp;M.&nbsp;R., McMurry,&nbsp;P.&nbsp;H., and Smith,&nbsp;J.&nbsp;N.: Estimating nanoparticle growth rates from size-dependent charged fractions: Analysis of new particle formation events in Mexico City, J. Geophys. Res.-Atmos., 113, D05207, https://doi.org/10.1029/2007JD009260, 2008. Jaitly,&nbsp;N., Monroe,&nbsp;M.&nbsp;E., Petyuk,&nbsp;V.&nbsp;A., Clauss,&nbsp;T.&nbsp;R.&nbsp;W., Adkins,&nbsp;J.&nbsp;N., and Smith,&nbsp;R.&nbsp;D.: Robust algorithm for alignment of liquid chromatography-mass spectrometry analyses in an accurate mass and time tag data analysis pipeline, Anal. Chem., 78, 7397–7409, 2006. Järvi,&nbsp;L., Hannuniemi,&nbsp;H., Hussein,&nbsp;T., Junninen,&nbsp;H., Aalto,&nbsp;P.&nbsp;P., Hillamo,&nbsp;R., Makela,&nbsp;T., Keronen,&nbsp;P., Siivola,&nbsp;E., Vesala,&nbsp;T., and Kulmala,&nbsp;M.: The urban measurement station SMEAR III: Continuous monitoring of air pollution and surface-atmosphere interactions in Helsinki, Finland, Boreal Environ. Res., 14, 86–109, 2009. Jayne,&nbsp;J.&nbsp;T., Leard,&nbsp;D.&nbsp;C., Zhang,&nbsp;X.&nbsp;F., Davidovits,&nbsp;P., Smith,&nbsp;K.&nbsp;A., Kolb,&nbsp;C.&nbsp;E., and Worsnop,&nbsp;D.&nbsp;R.: Development of an aerosol mass spectrometer for size and composition analysis of submicron particles, Aerosol Sci. Technol., 33, 49–70, 2000. Jimenez,&nbsp;J.&nbsp;L., Canagaratna,&nbsp;M.&nbsp;R., Donahue,&nbsp;N.&nbsp;M., Prevot,&nbsp;N.&nbsp;M., Zhang,&nbsp;Q., Kroll,&nbsp;J.&nbsp;H., DeCarlo,&nbsp;P.&nbsp;F., Allan,&nbsp;J.&nbsp;D., Coe,&nbsp;H., Ng,&nbsp;N.&nbsp;L., Aiken,&nbsp;A.&nbsp;C., Docherty,&nbsp;K.&nbsp;S., Ulbrich,&nbsp;I.&nbsp;M., Grieshop,&nbsp;A.&nbsp;P., Robinson,&nbsp;A.&nbsp;L., Duplissy,&nbsp;J., Smith,&nbsp;J.&nbsp;D., Wilson,&nbsp;K.&nbsp;R., Lanz,&nbsp;V.&nbsp;A., Hueglin,&nbsp;C., Sun,&nbsp;Y.&nbsp;L., Tian,&nbsp;J., Laaksonen,&nbsp;A., Raatikainen,&nbsp;T., Rautiainen,&nbsp;J., Vaattovaara,&nbsp;P., Ehn,&nbsp;M., Kulmala,&nbsp;M., Tomlinson,&nbsp;J.&nbsp;M., Collins,&nbsp;D.&nbsp;R., Cubison,&nbsp;M.&nbsp;J., Dunlea,&nbsp;E.&nbsp;J., Huffman,&nbsp;J.&nbsp;A., Onasch,&nbsp;T.&nbsp;B., Alfarra,&nbsp;M.&nbsp;R., Williams,&nbsp;P.&nbsp;I., Bower,&nbsp;K., Kondo,&nbsp;Y., Schneider,&nbsp;J., Drewnick,&nbsp;F., Borrmann,&nbsp;S., Weimer,&nbsp;S., Demerjian,&nbsp;K., Salcedo,&nbsp;D., Cottrell,&nbsp;L., Griffin,&nbsp;R., Takami,&nbsp;A., Miyoshi,&nbsp;T., Hatakeyama,&nbsp;S., Shimono,&nbsp;A., Sun,&nbsp;J.&nbsp;Y., Zhang,&nbsp;Y.&nbsp;M., Dzepina,&nbsp;K., Kimmel,&nbsp;J.&nbsp;R., Sueper,&nbsp;D., Jayne,&nbsp;J.&nbsp;T., Herndon,&nbsp;S.&nbsp;C., Trimborn,&nbsp;A.&nbsp;M., Williams,&nbsp;L.&nbsp;R., Wood,&nbsp;E.&nbsp;C., Middlebrook,&nbsp;A.&nbsp;M., Kolb,&nbsp;C.&nbsp;E., Baltensperger,&nbsp;U., and Worsnop,&nbsp;D.&nbsp;R.: Evolution of Organic Aerosols in the Atmosphere, Science, 326, 1525–1529, 2009. Jordan,&nbsp;A., Haidacher,&nbsp;S., Hanel,&nbsp;G., Hartungen,&nbsp;E., Mark,&nbsp;L., Seehauser,&nbsp;H., Schottkowsky,&nbsp;R., Sulzer,&nbsp;P., and Mark,&nbsp;T.&nbsp;D.: A&nbsp;high resolution and high sensitivity proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS), Int. J. Mass. Spectrom., 286, 122–128, 2009. Kendrick,&nbsp;E.: A&nbsp;mass scale based on $\chem{CH_2}=14.0000$ for high resolution mass spectrometry of organic compounds, Anal. Chem., 35, 2146–2154, 1963. Kerminen,&nbsp;V.-M., Pirjola,&nbsp;L., and Kulmala,&nbsp;M.: How signifigantly does coagulation scavening limit atmospheric particle production?, J. Geophys. Res., 106, 24119–24125, 2001. Ku,&nbsp;B.&nbsp;K. and Fernandez de la Mora, J.: Relation between electrical mobility, mass, and size for nanodrops 1–6.5 nm in diameter in air, Aerosol Sci. Technol., 43, 241–249, 2009. Kulmala,&nbsp;M. and Kerminen,&nbsp;V.&nbsp;M.: On the formation and growth of atmospheric nanoparticles, Atmos. Res., 90, 132–150, 2008. Kulmala,&nbsp;M., Riipinen,&nbsp;I., Sipila,&nbsp;M., Manninen,&nbsp;H.&nbsp;E., Petaja,&nbsp;T., Junninen,&nbsp;H., Dal Maso,&nbsp;M., Mordas,&nbsp;G., Mirme,&nbsp;A., Vana,&nbsp;M., Hirsikko,&nbsp;A., Laakso,&nbsp;L., Harrison,&nbsp;R.&nbsp;M., Hanson,&nbsp;I., Leung,&nbsp;C., Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J., and Kerminen,&nbsp;V.&nbsp;M.: Toward direct measurement of atmospheric nucleation, Science, 318, 89–92, 2007. Kulmala,&nbsp;M., Vehkamaki,&nbsp;H., Petaja,&nbsp;T., Dal Maso,&nbsp;M., Lauri,&nbsp;A., Kerminen,&nbsp;V.&nbsp;M., Birmili,&nbsp;W., and McMurry,&nbsp;P.&nbsp;H.: Formation and growth rates of ultrafine atmospheric particles: a&nbsp;review of observations, J. Aerosol Sci., 35, 143–176, 2004. Kulmala,&nbsp;M.: How particles nucleate and grow, Science, 302, 1000–1001, 2003. Marquardt,&nbsp;D.&nbsp;W.: An algorithm for least-squares estimation of nonlinear parameters, J. Soc. Ind. Appl. Math., 11, 431–441, 1963. Martinez-Lozano,&nbsp;P. and de la Mora,&nbsp;J.&nbsp;F.: On-line detection of human skin vapors, J. Am. Soc. Mass. Spectr., 20, 1060–1063, 2009. Mirme,&nbsp;A., Tamm,&nbsp;E., Mordas,&nbsp;G., Vana,&nbsp;M., Uin,&nbsp;J., Mirme,&nbsp;S., Bernotas,&nbsp;T., Laakso,&nbsp;L., Hirsikko,&nbsp;A. and Kulmala,&nbsp;M.: A&nbsp;wide-range multi-channel air ion spectrometer, Boreal Environ. Res., 12, 247–264, 2007. O'Dowd,&nbsp;C.&nbsp;D., Jimenez,&nbsp;J.&nbsp;L., Bahreini,&nbsp;R., Flagan,&nbsp;R.&nbsp;C., Seinfeld,&nbsp;J.&nbsp;H., Hameri,&nbsp;K., Pirjola,&nbsp;L., Kulmala,&nbsp;M., Jennings,&nbsp;S.&nbsp;G., and Hoffmann,&nbsp;T.: Marine aerosol formation from biogenic iodine emissions, Nature, 417, 632–636, 2002. Ortega, I. K., Kurtén, T., Vehkamäki, H., and Kulmala, M.: Corrigendum to "The role of ammonia in sulfuric acid ion induced nucleation" published in Atmos. Chem. Phys., 8, 2859–2867, 2008, Atmos. Chem. Phys., 9, 7431–7434, https://doi.org/10.5194/acp-9-7431-2009, 2009. Östman,&nbsp;P., Marttila,&nbsp;S.&nbsp;J., Kotiaho,&nbsp;T., Franssila,&nbsp;S., and Kostiainen,&nbsp;R.: Microchip atmospheric pressure chemical ionization source for mass spectrometry, Anal. Chem., 76, 6659–6664, 2004. Saarela,&nbsp;V., Haapala,&nbsp;M., Kostiainen,&nbsp;R., Kotiaho,&nbsp;T., and Franssila,&nbsp;S.: Glass microfabricated nebulizer chip for mass spectrometry, Lab Chip, 7, 644–646, 2007. Sipila,&nbsp;M., Lehtipalo,&nbsp;K., Attoui,&nbsp;M., Neitola,&nbsp;K., Petaja,&nbsp;T., Aalto,&nbsp;P.&nbsp;P., O'Dowd,&nbsp;C.&nbsp;D., and Kulmala,&nbsp;M.: Laboratory verification of PH-CPC's ability to monitor atmospheric sub-3 nm clusters, Aerosol Sci. Technol., 43, 126–135, 2009. Sipilä, M., Lehtipalo, K., Kulmala, M., Petäjä, T., Junninen, H., Aalto, P. P., Manninen, H. E., Kyrö, E.-M., Asmi, E., Riipinen, I., Curtius, J., Kürten, A., Borrmann, S., and O'Dowd, C. D.: Applicability of condensation particle counters to measure atmospheric clusters, Atmos. Chem. Phys., 8, 4049–4060, https://doi.org/10.5194/acp-8-4049-2008, 2008. Smith,&nbsp;J.&nbsp;N., Dunn,&nbsp;M.&nbsp;J., Vanreken,&nbsp;T.&nbsp;M., Iida,&nbsp;K., Stolzenburg,&nbsp;M.&nbsp;R., McMurry,&nbsp;P.&nbsp;H., and Huey,&nbsp;L.&nbsp;G.: Chemical composition of atmospheric nanoparticles formed from nucleation in Tecamac, Mexico: Evidence for an important role for organic species in nanoparticle growth, Geophys. Res. Lett., 35, L04808, https://doi.org/10.1029/2007GL032523, 2008. Smith,&nbsp;J.&nbsp;N., Moore,&nbsp;K.&nbsp;F., Eisele,&nbsp;F.&nbsp;L., Voisin,&nbsp;D., Ghimire,&nbsp;A.&nbsp;K., Sakurai,&nbsp;H., and McMurry,&nbsp;P.&nbsp;H.: Chemical composition of atmospheric nanoparticles during nucleation events in Atlanta,&nbsp;J. Geophys. Res., 110, D22S03, <a href="http://dx.doi.org/10.1029/2005JD005912">https://doi.org/10.1029/2005JD005912</a>, 2005. Smith,&nbsp;J.&nbsp;S., Laskin,&nbsp;A., and Laskin,&nbsp;J.: Molecular characterization of biomass burning aerosols using high-resolution mass spectrometry, Anal. Chem., 81, 1512–1521, 2009. Tanner,&nbsp;D.&nbsp;J. and Eisele,&nbsp;F.&nbsp;L.: Ions in oceanic and continental air masses, J. Geophys. Res.-Atmos., 96, 1023–1031, 1991. Ude,&nbsp;S. and Fernandez de la Mora,&nbsp;J.&nbsp;F.: Molecular monodisperse mobility and mass standards from electrosprays of tetra-alkyl ammonium halides, J. Aerosol. Sci., 36, 1224–1237, 2005. Voisin,&nbsp;D., Smith,&nbsp;J.&nbsp;N., Sakurai,&nbsp;H., McMurry,&nbsp;P.&nbsp;H., and Eisele,&nbsp;F.&nbsp;L.: Thermal desorption chemical ionization mass spectrometer for ultrafine particle chemical composition, Aerosol Sci. Technol., 37, 471–475, 2003. Vorm,&nbsp;O. and Mann,&nbsp;M.: Improved Mass Accuracy in Matrix-Assisted Laser Desorption/Ionization Timeof- Flight Mass-Spectrometry of Peptides, J. Am. Soc. Mass. Spectr., 5, 955–958, 1994. Wolski,&nbsp;W.&nbsp;E., Lalowski,&nbsp;M., Jungblut,&nbsp;P., and Reinert,&nbsp;K.: Calibration of mass spectrometric peptide mass fingerprint data without specific external or internal calibrants, BMC Bioinformatics, 6, 203, https://doi.org/10.1186/1471-2105-6-203, 2005. Zhao,&nbsp;J., Eisele,&nbsp;F.&nbsp;L., Titcombe,&nbsp;M., Kuang,&nbsp;C., and McMurry,&nbsp;P.&nbsp;H.: Chemical ionization mass spectrometric measurements of atmospheric neutral clusters using the Cluster-CIMS, J. Geophys. Res., , https://doi.org/10.1029/2009JD012606, 2010.