C279etukansi.kesken.fm Page 1 Thursday, August 16, 2007 1:57 PM C 279 OULU 2007 C 279 UNIVERSITY OF OULU P.O. Box 7500 FI-90014 UNIVERSITY OF OULU FINLAND ACTA UNIVERSITATIS OULUENSIS ACTA UNIVERSITATIS OULUENSIS ACTA C SERIES EDITORS Arja Sarpola TECHNICA ArjaSarpola ASCIENTIAE RERUM NATURALIUM Professor Mikko Siponen THE HYDROLYSIS OF BHUMANIORA ALUMINIUM, A MASS Professor Harri Mantila SPECTROMETRIC STUDY CTECHNICA Professor Juha Kostamovaara DMEDICA Professor Olli Vuolteenaho ESCIENTIAE RERUM SOCIALIUM Senior Assistant Timo Latomaa FSCRIPTA ACADEMICA Communications Officer Elna Stjerna GOECONOMICA Senior Lecturer Seppo Eriksson EDITOR IN CHIEF Professor Olli Vuolteenaho EDITORIAL SECRETARY Publications Editor Kirsti Nurkkala FACULTY OF TECHNOLOGY, DEPARTMENT OF PROCESS AND ENVIRONMENTAL ENGINEERING, WATER RESOURCES AND ENVIRONMENTAL ENGINEERING LABORATORY, ISBN 978-951-42-8556-1 (Paperback) UNIVERSITY OF OULU ISBN 978-951-42-8557-8 (PDF) ISSN 0355-3213 (Print) ISSN 1796-2226 (Online) ACTA UNIVERSITATIS OULUENSIS C Technica 279 ARJA SARPOLA THE HYDROLYSIS OF ALUMINIUM, A MASS SPECTROMETRIC STUDY Academic dissertation to be presented, with the assent of the Faculty of Technology of the University of Oulu, for public defence in Raahensali (Auditorium L10), Linnanmaa, on September 28th, 2007, at 12 noon OULUN YLIOPISTO, OULU 2007 Copyright © 2007 Acta Univ. Oul. C 279, 2007 Supervised by Doctor Jaakko Rämö Reviewed by Doctor Christopher Exley Doctor Tamás Kiss ISBN 978-951-42-8556-1 (Paperback) ISBN 978-951-42-8557-8 (PDF) http://herkules.oulu.fi/isbn9789514285578/ ISSN 0355-3213 (Printed) ISSN 1796-2226 (Online) http://herkules.oulu.fi/issn03553213/ Cover design Raimo Ahonen OULU UNIVERSITY PRESS OULU 2007 Sarpola, Arja, The hydrolysis of aluminium, a mass spectrometric study Faculty of Technology, Department of Process and Environmental Engineering, Water Resources and Environmental Engineering Laboratory, University of Oulu, P.O.Box 4300, FI-90014 University of Oulu, Finland Acta Univ. Oul. C 279, 2007 Oulu, Finland Abstract This thesis is focused on the hydrolysis of aluminium, the polymerisation of the hydrolysis products, and how these can be monitored by mass spectrometric methods. The main aim of this research is to figure out how the aqueous speciation of aluminium changes as a function of pH (3.2–10), - 2- - concentration (1–100 mM), reaction time (1s–14d), and counter anion (Cl , SO4 , HCOO ). The method used was electrospray mass spectrometry. The results showed more variable speciation than those suggested earlier. The main species were Al2, Al3, and Al13, which were found in all of the conditions under scrutiny. The effect of pH was the most remarkable of all the parameters researched. The formation of large highly charged complexes was strongly dependent on it. Also the Al- concentration in the bulk solution had a clear effect on speciation: in dilute solutions there were more protonated ligands and less attached counter anions. This could mean that the species in more diluted bulk solutions had fewer different states of charge. Reaction time caused only minor changes to speciation in the initial pH: there was slightly more variation of a certain sized species in the aged solution. In elevated pH, the birth of important Al13 oligomers was time dependent. The effect of the counter anion was tremendous. In a chloride environment the speciation was rich and diversified. With sulphate the speciation was limited to solid- like compounds, and the variation of single-sized species was almost lacking. The formate as a counter anion caused most surprising results; the charge of aluminium in some studied complexes was lowered from the common 3+ to 1+. If this reaction also occurs in natural circumstances, the uses of aluminium formate would be wide. The results can be utilised in following the progress of dissolution, the mobilization and toxicity of aluminium in natural waters, as well as in water purification, and in reaching minimal chemical contamination levels in sludge as well as in aqueous waste. Keywords: aluminium, coagulation, electrospray, mass spectrometry, speciation, water treatment Acknowledgements I wish to express my gratitude to my supervisor Dr. Jaakko Rämö from Oulu University and my advisors Dr. Jorma Jalonen from Oulu University and Dr. Vesa Hietapelto from Kemira Inc. Kemira Inc., the Oulu University Scholarship Foundation, the Ministry of Education (Graduate School of Inorganic Material Chemistry), the Kemira Foundation, the Orion Research Foundation, the Maj- and Tor Nessling Foundation, the University of Oulu, The Yliopiston Apteekki Fund, who financed this research are gratefully remembered. An acknowledgement to Päivi Joensuu and Sari Ek at the Mass Laboratory of Oulu University for their practical advice. I have received great help from my colleagues Heikki Hellman and Tiina Leiviskä. Jaakko Saukkoriipi assured many confirmations by computational methods, which I am very grateful for. Also the discussions with Prof. Kari Laasonen and Dr. Jukka Jokela have been the most rewarding. Prof. Björn Klöve, Prof. Risto Laitinen, Anna-Kaisa Ronkanen, Dr. Jarmo Sallanko, Dr. Leena Kaila, Prof. Paavo Perämäki, Helena Paaso, Paavo Vehkomäki and many other people from University of Oulu have been most supporting both in terms of scientific and practical matters. Thank you all. I am also grateful to MSc. Ilari Sohlo for his expert knowledge and hard work he has done to improve the language of this thesis. Last but not least, great thanks to my family, who have encouraged me to carry on researching despite the mountains of dirty dishes, collapsing laundry piles and the breeding of dust balls in corners. At Muhos, 13 September 2006 Arja Sarpola 6 Table of acronyms and symbols z Aln n aluminium containing oxo hydroxo complex with the charge z 2+ 2+ e.g. [Al13O4(OH)29] = Al13 α−AlO(OH) diaspore, an aluminium mineral γ−AlO(OH) boehmite, an aluminium mineral α−Al(OH)3 bayerite, an aluminium mineral Al(OH)3 gibbsite, an aluminium mineral Al2O3 corundum, an aluminium mineral Bauxite rock, a mixture of boehmite, gibbsite, and diaspore ESI electrospray ionisation FT-ICR Fourier-transform ion cyclotron resonance mass spectrometry IR infra-red spectroscopy MS mass spectrometer MS/MS tandem mass spectrometry MS-Q quadrupole mass spectrometer m/z mass-to-charge ratio M unit of concentration; mol/L, mol dm-3 mM unit of concentration; mill mol/L, 10-3 mol dm-3 μM unit of concentration; micro mol/L, 10-6 mol dm-3 μ−OH terminal OH-ligand μ2−OH bridging OH-ligand μ3−OH central OH-ligand, e.g., in a trimeric ring structure NMR nuclear magnetic resonance TIC total ion count in a mass spectrometer TOF time of flight detection XRD X-ray diffraction 7 8 List of original papers I Sarpola A, Hietapelto V, Jalonen J, Jokela J & Laitinen RS (2004) Identification of the hydrolysis products of AlCl3•6H2O by electrospray ionization mass spectrometry. Journal of Mass Spectrometry 39: 423. DOI: 10.1002/jms.607. II Sarpola A, Hietapelto V, Jalonen J, Jokela J, Laitinen RS & Rämö J (2004) Identification and fragmentation of hydrolysed aluminum species by electrospray ionization tandem mass spectrometry. Journal of Mass Spectrometry 39: 1209. DOI: 10.1002/jms.722. III Sarpola A, Hietapelto V, Jalonen J, Jokela J &Rämö J (2006) Comparison of the hydrolysis products of AlCl3•6H2O in different concentrations by electrospray ionization time of flying mass spectrometer. International Journal of Environmental Analytical Chemistry 86: 1007. DOI: 10.1080/03067310600687583. IV Sarpola A, Hellman H, Hietapelto V, Jalonen J, Jokela J, Rämö J & Saukkoriipi J (2007) Hydrolysis products of water treatment chemical aluminium sulfate octadecahydrate by electrospray ionization mass spectrometry; connection with mineral compositions. Polyhedron 26: 2581-2588. DOI:10.1016/j.poly.2007.01.035. V Sarpola A, Saukkoriipi J, Hietapelto V, Jalonen J, Jokela J, Laasonen K & Rämö J (2007) Identification of hydrolysis products of AlCl3•6H2O with presence of sulphate by electrospray ionization time of flight mass spectrometry and computational methods. Physical Chemistry Chemical Physics 9: 377–388. DOI: 10.1039/b614814j. 9 10 Table of contents Abstract Acknowledgements 5 Table of acronyms and symbols 7 List of original papers 9 Table of contents 11 1 Introduction 13 2 Water treatment 17 3 Hydrolysis of aluminium 19 4 Traditional methods of studying of hydrolysis of aluminium 25 4.1 Potentiometric titration and calculated speciation................................... 25 4.2 The 27Al-NMR ........................................................................................ 27 4.3 The spectrophotometric detection........................................................... 27 4.4 The surface analysis................................................................................ 28 4.5 Computational chemistry ........................................................................ 30 5 The mass spectrometric method 31 5.1 Electrospray ionization (ESI).................................................................. 32 5.2 Time of flight analyser (TOF)................................................................. 36 5.3 MS/MS with triple quadrupoles.............................................................. 37 6 Speciation of aluminium detected by mass spectrometer 40 6.1 Anionic aluminium species..................................................................... 42 6.2 Monomers ..............................................................................................