Laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF): Performance, reference spectra and classification of atmospheric samples

Abstract. The laser ablation aerosol particles time-of-flight mass spectrometer (LAAPTOF, Aeromegt GmbH) is able to identify the chemical composition and mixing state of individual aerosol particles, and thus is a tool for elucidating their impacts on human health, visibility, ecosystem and climate. The overall detection efficiency (ODE) of the instrument we use was determined to range from ~(0.01 ± 0.01) % to ~(6.57 ± 2.38) % for polystyrene latex (PSL), ammonium nitrate (NH4NO3), and sodium chloride (NaCl) particles in the size rage of 200 to 2000 nm. Reference mass spectra of 32 different particle types relevant for atmospheric aerosol (e.g. pure compounds NH4NO4, K2SO4, NaCl, oxalic acid, pinic acid, and pinonic acid; internal mixtures of e.g. salts, secondary organic aerosol, and metallic core-organic shell particles; more complex particles such as soot and dust particles) were determined. Our results show that internally mixed aerosol particles can result in spectra with new clusters of ions, rather than simply a combination of the spectra from the single components. An exemplary one-day ambient data set was analysed by classical Fuzzy-clustering leading to six different particle classes. Correlating these particle classes with the reference spectra as well as direct comparison of the ambient data with the reference spectra has proven how useful they are for the interpretation of field measurements, for e.g. grouping data, and identifying special particle types and potential sources.

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Laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF): performance, reference spectra and classification of atmospheric samples

Atmospheric Measurement Techniques ◽

10.5194/amt-11-2325-2018 ◽

2018 ◽

Vol 11 (4) ◽

pp. 2325-2343 ◽

Cited By ~ 11

Author(s):

Xiaoli Shen ◽

Ramakrishna Ramisetty ◽

Claudia Mohr ◽

Wei Huang ◽

Thomas Leisner ◽

...

Keyword(s):

Laser Ablation ◽

Aerosol Particle ◽

Mass Spectrometer ◽

Size Range ◽

Aerosol Particles ◽

Time Of Flight ◽

Polystyrene Latex ◽

Dust Particles ◽

Data Set ◽

Flight Mass Spectrometer

Abstract. The laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF, AeroMegt GmbH) is able to identify the chemical composition and mixing state of individual aerosol particles, and thus is a tool for elucidating their impacts on human health, visibility, ecosystem, and climate. The overall detection efficiency (ODE) of the instrument we use was determined to range from ∼  (0.01 ± 0.01) to ∼  (4.23 ± 2.36) % for polystyrene latex (PSL) in the size range of 200 to 2000 nm, ∼  (0.44 ± 0.19) to ∼  (6.57 ± 2.38) % for ammonium nitrate (NH4NO3), and ∼  (0.14 ± 0.02) to ∼  (1.46 ± 0.08) % for sodium chloride (NaCl) particles in the size range of 300 to 1000 nm. Reference mass spectra of 32 different particle types relevant for atmospheric aerosol (e.g. pure compounds NH4NO3, K2SO4, NaCl, oxalic acid, pinic acid, and pinonic acid; internal mixtures of e.g. salts, secondary organic aerosol, and metallic core–organic shell particles; more complex particles such as soot and dust particles) were determined. Our results show that internally mixed aerosol particles can result in spectra with new clusters of ions, rather than simply a combination of the spectra from the single components. An exemplary 1-day ambient data set was analysed by both classical fuzzy clustering and a reference-spectra-based classification method. Resulting identified particle types were generally well correlated. We show how a combination of both methods can greatly improve the interpretation of single-particle data in field measurements.

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Direct Chemical Analysis of Solids by Laser Ablation in an Ion Storage Time-of-Flight Mass Spectrometer

Analytical Chemistry ◽

10.1021/ac0303261 ◽

2004 ◽

Vol 76 (5) ◽

pp. 1249-1256 ◽

Cited By ~ 21

Author(s):

Gregory L. Klunder ◽

Patrick M. Grant ◽

Brian D. Andresen ◽

Richard E. Russo

Keyword(s):

Laser Ablation ◽

Chemical Analysis ◽

Mass Spectrometer ◽

Storage Time ◽

Time Of Flight ◽

Flight Mass Spectrometer ◽

Ion Storage

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The Cosmic Dust Analyzer: Experimental Evaluation of an Impact Ionization Model

International Astronomical Union Colloquium ◽

10.1017/s0252921100049216 ◽

1971 ◽

Vol 13 ◽

pp. 299-310

Author(s):

J. F. Friichtenicht ◽

N. L. Roy ◽

D. G. Becker

Keyword(s):

Mass Spectrometer ◽

Relative Abundance ◽

Microprobe Analysis ◽

Impact Ionization ◽

Time Of Flight ◽

Cosmic Dust ◽

Dust Particles ◽

Flight Mass Spectrometer ◽

Fractional Ionization ◽

The Impact

Determination of the elemental composition of cosmic dust particles by means of an impact ionization time-of-flight mass spectrometer has been investigated at several institutions. In most configurations, the instrument supplies the identity of ion groups of both target and particle materials extracted from the impact plasma and the number of ions contained in each group. Experiments have shown that the fractional ionization of a given species is not constant with impact velocity nor is the fractional ionization the same for different kinds of atoms. A model of the impact ionization effect developed at TRW involves an equilibrium plasma condition with the consequence that the fractional ionization for an arbitrary atomic species can be specified by the Saha equation if the plasma volume (V) and temperature (T) are known. It follows that T can be determined by taking the ratio of the Saha equations for two elements present in the target in known concentration. (Taking the ratio negates the requirement of knowing V.) Given T, the procedure can be reversed to yield the relative abundance of elements contained in the impacting particle. To test the model, a PbZrO3-PbTiO3 target was bombarded with high velocity Fe, MoB, and NiAl particles and the number of Pb, Ti, and Zr ions was determined in a time-of-flight mass spectrometer. For each event, the relative abundance of Ti to Pb was taken as known (from electron microprobe analysis) and T was determined from the Ti-Pb measurement. The Zr to Pb ratio was found to be in good agreement with the microprobe analysis (0.38 calculated mean value compared to 0.34 actual). The result was valid for all particle materials and for a velocity range 17<v<47 km/s. T ranged from 3300 to 11 500° K and was only mildly velocity dependent.

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Quantifying and improving the performance of the Laser Ablation Aerosol Particle Time of Flight Mass Spectrometer (LAAPToF) instrument

10.5194/amt-2017-1 ◽

2017 ◽

Cited By ~ 1

Author(s):

Maria A. Zawadowicz ◽

Sara Lance ◽

John T. Jayne ◽

Philip Croteau ◽

Douglas R. Worsnop ◽

...

Keyword(s):

Laser Ablation ◽

Aerosol Particle ◽

Mass Spectrometer ◽

Time Of Flight ◽

Flight Mass Spectrometer

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On the application of a linear time-of-flight mass spectrometer for the investigation of hypervelocity impacts of micron and sub-micron sized dust particles

Planetary and Space Science ◽

10.1016/j.pss.2013.07.013 ◽

2013 ◽

Vol 89 ◽

pp. 47-57 ◽

Cited By ~ 5

Author(s):

Anna Mocker ◽

Klaus Hornung ◽

Eberhard Grün ◽

Sascha Kempf ◽

Andrew Collette ◽

...

Keyword(s):

Mass Spectrometer ◽

Linear Time ◽

Time Of Flight ◽

Dust Particles ◽

Hypervelocity Impacts ◽

Flight Mass Spectrometer

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Development and characterization of a single particle laser ablation mass spectrometer (SPLAM) for organic aerosol studies

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-4-4165-2011 ◽

2011 ◽

Vol 4 (4) ◽

pp. 4165-4208

Author(s):

F. Gaie-Levrel ◽

S. Perrier ◽

E. Perraudin ◽

C. Stoll ◽

N. Grand ◽

...

Keyword(s):

Laser Ablation ◽

Detection Limit ◽

Mass Spectrometer ◽

Single Particle ◽

Detection Efficiency ◽

Linear Time ◽

Scattered Light ◽

Optical Detection ◽

Organic Aerosol ◽

Polystyrene Latex

Abstract. A single particle instrument has been developed for real-time analysis of organic aerosols. This instrument, named Single Particle Laser Ablation Mass Spectrometry (SPLAM), samples particles using an aerodynamic lens system for which the theoretical performances were calculated. At the outlet of this system, particle detection and sizing are realized using two continuous diode lasers operating at λ = 403 nm. Polystyrene Latex (PSL), sodium chloride (NaCl) and dioctylphtalate (DOP) particles were used to characterize and calibrate optical detection of SPLAM. The optical detection limit (DL) and detection efficiency (DE) were determined using size-selected DOP particles. The DE is ranging from 0.1 to 90 % for 100 and 350 nm DOP particles respectively and the SPLAM instrument is able to detect and size-resolve particles as small as 110–120 nm. Scattered light is detected by two photomultipliers and the detected signals are used to trigger a UV excimer laser (λ = 248 nm) used for laser desorption ionization (LDI) of individual aerosol particles. The formed ions are analyzed by a 1 m linear time-of-flight mass spectrometer in order to access to the chemical composition of individual particles. The TOF-MS detection limit for gaseous aromatic compounds was determined to be 0.85 attograms. DOP particles were also used to test the overall functioning of the instrument. The analysis of a secondary organic aerosol, formed in a smog chamber by the ozonolysis of indene, is presented as a first scientific application of the instrument. Single particle mass spectra are obtained with a global hit rate of 10 %. They are found to be very different from one particle to another, reflecting chemical differences of the analyzed particles, and most of the detected mass peaks are attributed to oxidized products of indene.

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