Instrumentation, data evaluation and quantification in on‐line aerosol mass spectrometry

Hinz, Klaus-Peter; Spengler, Bernhard

doi:10.1002/jms.1262

Cited by 74 publications

(70 citation statements)

References 149 publications

(306 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Zhao et al, 2005;Zhou et al, 2006) were used and discussed in the literature. A comparison of different clustering algorithm is presented by Hinz and Spengler (2007) and Rebotier and Prather (2007). For analysis of the SPLAT single particle data the open source data mining program Rapid Miner Version 4.1 (Mierswa et al, 2006) was used.…”

Section: Splatmentioning

confidence: 99%

Chemical composition of ambient aerosol, ice residues and cloud droplet residues in mixed-phase clouds: single particle analysis during the Cloud and Aerosol Characterization Experiment (CLACE 6)

et al. 2010

View full text Add to dashboard Cite

Abstract. Two different single particle mass spectrometers were operated in parallel at the Swiss High Alpine Research Station Jungfraujoch (JFJ, 3580 m a.s.l.) during the Cloud and Aerosol Characterization Experiment (CLACE 6) in February and March 2007. During mixed phase cloud events ice crystals from 5-20 µm were separated from larger ice aggregates, non-activated, interstitial aerosol particles and supercooled droplets using an Ice-Counterflow Virtual Impactor (Ice-CVI). During one cloud period supercooled droplets were additionally sampled and analyzed by changing the Ice-CVI setup. The small ice particles and droplets were evaporated by injection into dry air inside the Ice-CVI. The resulting ice and droplet residues (IR and DR) were analyzed for size and composition by the two single particle mass spectrometers: a custom-built Single Particle Laser-Ablation Time-of-Flight Mass Spectrometer (SPLAT) and a commercial Aerosol Time-of-Flight Mass Spectrometer (ATOFMS, TSI Model 3800). During CLACE 6 the SPLAT instrument characterized 355 individual IR that produced a mass spectrum for at least one polarity and the ATOFMS measured 152 IR. The mass spectra were binned Correspondence to: J. Curtius (curtius@iau.uni-frankfurt.de) in classes, based on the combination of dominating substances, such as mineral dust, sulfate, potassium and elemental carbon or organic material. The derived chemical information from the ice residues is compared to the JFJ ambient aerosol that was sampled while the measurement station was out of clouds (several thousand particles analyzed by SPLAT and ATOFMS) and to the composition of the residues of supercooled cloud droplets (SPLAT: 162 cloud droplet residues analyzed, ATOFMS: 1094). The measurements showed that mineral dust was strongly enhanced in the ice particle residues. Close to all of the SPLAT spectra from ice residues did contain signatures from mineral compounds, albeit connected with varying amounts of soluble compounds. Similarly, close to all of the ATOFMS IR spectra show a mineral or metallic component. Pure sulfate and nitrate containing particles were depleted in the ice residues. Sulfate and nitrate was found to dominate the droplet residues (∼90% of the particles). The results from the two different single particle mass spectrometers were generally in agreement. Differences in the results originate from several causes, such as the different wavelength of the desorption and ionisation lasers and different size-dependent particle detection efficiencies.

show abstract

Section: Splatmentioning

confidence: 99%

Chemical composition of ambient aerosol, ice residues and cloud droplet residues in mixed-phase clouds: single particle analysis during the Cloud and Aerosol Characterization Experiment (CLACE 6)

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The covariance matrix for ammonium sulfate/nitrate particles is interpreted within the context of the same two-stage process considered for NaCl: an initial ionization step to produce cations and electrons, followed by electron capture and/or chargetransfer in the plume. However, unlike NaCl, particles containing ammonium sulfate and nitrate are more likely to disintegrate into stable molecules such as HNO 3 , H 2 SO 4 , NH 3 , and NO x when ablated, which are the species that subsequently undergo ionization. The strong negative correlations of the ion pairs NO ϩ /H ϩ and NO ϩ /NH 4 ϩ indicate that these ions are undergo competitive charge-transfer in the plume.…”

Section: Covariance Mappingmentioning

confidence: 99%

“…While a variety of ionization schemes have been used, single step laser desorption ionization (LDI) is the most common [1][2][3]. In our laboratory, RSMS uses a single 193 nm laser pulse to ablate and ionize material from the particle [4].…”

mentioning

confidence: 99%

Ion formation mechanism in laser desorption ionization of individual nanoparticles

Reinard

Johnston

2008

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Covariance mapping is used to study ion formation mechanisms in laser desorption ionization of individual 50 or 220 nm diameter particles having compositions similar to ambient aerosol. Single particle mass spectra are found to vary substantially from particle to particle. This variation is systematic-the energetically preferred ions (e.g., lowest ionization energy, highest electron affinity) are positively correlated with each other and negatively correlated with less preferred ions. For the compositions studied, the average positive ion yield is two to five times greater than the negative ion yield, indicating that free electrons are the main negatively charged species. For many particles, typically 20% to 40% of those analyzed, only positive ions are detected. Smaller particles give fewer negative ions, presumably because the plume is less dense and electron capture is less likely. The results suggest that ion formation occurs by a two stage process. In the first stage, photoionization of laser desorbed neutrals gives cations and free electrons. In the second stage, collisions in the plume cause electron capture and competitive charge transfer. When the particle ablates in a manner giving a dense plume with many collisions, the energetically preferred positive and negative ions are dominant. When the particle ablates in a manner giving a less dense plume with fewer collisions, the less preferred ions are able to survive and the energetically preferred ions constitute a lower fraction of the total ion signal. Systematic particle to particle variations of relative signal intensities can complicate ambient particle classification efforts by spreading a single particle composition over several classes. . In our laboratory, RSMS uses a single 193 nm laser pulse to ablate and ionize material from the particle [4]. Intense ion signals can be obtained from most particle compositions: refractory and semivolatile, organic and inorganic. A common feature of this and other laser desorption ionization sequences is that the ionization mechanism is not fully understood [2].The LDI mass spectra from single particle mass spectrometers are similar to those obtained with laser microprobe mass spectrometry (LAMMS), a decades old method capable of analyzing particles and bulk materials deposited on a substrate [5,6]. Similar to LAMMS, single particle mass spectrometers also ablate and ionize particles with high-energy laser pulses, but particles are suspended in the center of the source region and analyzed less than a millisecond after entering the vacuum [7].Some effort has been made to elucidate the mechanisms of LDI in single particle mass spectrometry. Measurements of the kinetic energy distribution of ions formed by LDI has provided some information regarding the physical processes that occur during ionization [8,9]. Computational models have characterized the disintegration of particles irradiated with a short laser pulse [10 -12]. Most studies of the ion formation mechanism in LDI, though, have been performed on solids and...

show abstract

“…Ions produced in a low vacuum source by the LDI process are analysed by time-offlight mass spectrometry (TOF-MS). However, the composition measurement is considered non-quantitative on a singleparticle basis due to variation in instrument function and particle matrix effects that influence the ion formation process (Hinz and Spengler, 2007;Murphy, 2007;Zhou et al, 2007). The origin of this matrix effect is not well understood, but systematic variation of ion signals in simple analogues of atmospheric aerosol suggests that ionisation potential, electron affinity and plume density are important factors (Reinard and Johnston, 2008).…”

Section: Introductionmentioning

confidence: 99%

Online differentiation of mineral phase in aerosol particles by ion formation mechanism using a LAAP-TOF single-particle mass spectrometer

et al. 2018

View full text Add to dashboard Cite

Abstract. Mineralogy of silicate mineral dust has a strong influence on climate and ecosystems due to variation in physiochemical properties that result from differences in composition and crystal structure (mineral phase). Traditional offline methods of analysing mineral phase are labour intensive and the temporal resolution of the data is much longer than many atmospheric processes. Single-particle mass spectrometry (SPMS) is an established technique for the online size-resolved measurement of particle composition by laser desorption ionisation (LDI) followed by time-of-flight mass spectrometry (TOF-MS). Although non-quantitative, the technique is able to identify the presence of silicate minerals in airborne dust particles from markers of alkali metals and silicate molecular ions in the mass spectra. However, the differentiation of mineral phase in silicate particles by traditional mass spectral peak area measurements is not possible. This is because instrument function and matrix effects in the ionisation process result in variations in instrument response that are greater than the differences in composition between common mineral phases.In this study, we introduce a novel technique that enables the differentiation of mineral phase in silicate mineral particles by ion formation mechanism measured from subtle changes in ion arrival times at the TOF-MS detector. Using a combination of peak area and peak centroid measurements, we show that the arrangement of the interstitial alkali metals in the crystal structure, an important property in silicate mineralogy, influences the ion arrival times of elemental and molecular ion species in the negative ion mass spectra. A classification scheme is presented that allowed for the differentiation of illite-smectite, kaolinite and feldspar minerals on a single-particle basis. Online analysis of mineral dust aerosol generated from clay mineral standards produced mineral fractions that are in agreement with bulk measurements reported by traditional XRD (X-ray diffraction) analysis.

show abstract

Instrumentation, data evaluation and quantification in on‐line aerosol mass spectrometry

Cited by 74 publications

References 149 publications

Chemical composition of ambient aerosol, ice residues and cloud droplet residues in mixed-phase clouds: single particle analysis during the Cloud and Aerosol Characterization Experiment (CLACE 6)

Chemical composition of ambient aerosol, ice residues and cloud droplet residues in mixed-phase clouds: single particle analysis during the Cloud and Aerosol Characterization Experiment (CLACE 6)

Ion formation mechanism in laser desorption ionization of individual nanoparticles

Online differentiation of mineral phase in aerosol particles by ion formation mechanism using a LAAP-TOF single-particle mass spectrometer

Contact Info

Product

Resources

About