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Methoden und Instrumentierung Poster: Mi., 14:00–16:30 M-P20
Elemental Analysis of Aerosols with SR-TXRF: Direct Calibration with
Pico-droplets (pL) Generated by Ink-Jet Printers
Ursula Fittschen 1 , Stephan Hauschild 1 , Christina Streli 2 , Gerhard
Lammel 3 , Peter Wobrauschek 2 , Florian Meirer 2 , Giancarlo Pepponi 4 ,
Stephan Förster 1 , Gerald Falkenberg 5 , José Broekaert 1
1 Department Chemie, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146
Hamburg – 2 Atominstitut der österreichischen Univeritäten, Technische Universität
Wien, Stadionallee 2, A-1020 Wien – 3 Max Planck Institut für Meterologie,
Bundesstraße 53, D-20146 Hamburg – 4 ITC-irst, Via Sommarive 18, I-38050
Povo (Trento) – 5 Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-
Synchrotron DESY, Notkestr. 85, D-22603 Hamburg
The impact of the chemical composition of airborne particles and its particle size dependence
on air quality and on climate has become apparent in recent years [1]. Particle
sources and sinks are strongly related to their size and so is the chemical composition
[2]. A number of metals and also non-metals like P, S, Cl and Br undergo chemical
transformations typically on the time scale of hours. These requirements translate to
10 −1 pg and even less of trace elements to be determined.
TXRF is a very sensitive method for element determinations which has been successfully
used for size-resolved aerosol analysis [3]. Even more sensitive is SR-XRF. Its
combination with size-resolved aerosol sampling is promising, as already shown in Ref.
[4].
An accurate and reliable calibration of SR-TXRF of aerosol samples collected is necessary
but difficult: The addition of standard solution with micropipettes may suffer
from destroying the sample spots or lines as a result of the relatively high amount of
liquid. Here we present the results of a study into the suitability of a calibration in
aerosol sample analysis by SR-TXRF using pico-droplets (i.e. 5-130 pL), generated by
inkjet printers. The procedure could be made compatible to aerosol particle sampling
using a Berner impactor. In the latter the aerosol particles are collected in different
complex patterns on the impaction stages. The diameter of the dried droplets ranges
from 50-200 µm for ink droplets printed on hydrophobic surfaces. The reliability of
the dosing of standard solution was satisfactory and enables a spotting of well-defined
absolute amounts of standard in the picogram range and below. Further, it was shown
that a printing according to a given pattern in the micrometer range can easily be done
with the aid of common computer software.
[1] J. E. Penner et al., Thierd Assessment Report of the Intergovernmental Panel
on Climate Change 2001 (J. T. Houghton et al., eds.), Cambridge University Press,
Cambridge, UK, pp. 289-348
[2] K. R. Spurny, CRC Press, Boca Raton, USA, 486 pp.
[3] B. Schneider, Spectrochim. Acta, Part B 44, (1989), 519-524
[4] N. Bukowiecki et al., Environ. Sci. Technol. 39 (2005), 5754-5762