Single-Particle Time-of-Flight Mass Spectrometry Utilizing a Femtosecond Desorption and Ionization Laser

Zawadowicz, Maria A.; Abdelmonem, Ahmed; Mohr, Claudia; Saathoff, H.; Froyd, K. D.; Murphy, D. M.; Leisner, Thomas; Cziczo, D. J.

doi:10.1021/acs.analchem.5b03158

Cited by 22 publications

(23 citation statements)

References 42 publications

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“…The ns-laser spectrum is representative of 500 particles. The positive spectrum consists of NH The ns-LAAPTOF bipolar spectrum is comparable to the ammonium nitrate single-particle spectrum obtained by the PALMS (Zawadowicz et al, 2015). NH 4 NO 3 predominantly leads to positive ions (NH (Neubauer et al, 1998), but in contradiction to observations with the PALMS (Zawadowicz et al, 2015) or the real-time single-particle mass spectrometer (RSMS) with excimer laser wavelength 193 nm (Reinard and Johnston, 2008).…”

Section: Nh 4 No 3 Particlesmentioning

confidence: 65%

“…We compare mass spectra of atmospherically relevant airborne particles and dedicated test particles from nsand fs-laser ablation using a commercially available laser ablation aerosol time-of-flight mass spectrometer (LAAPTOF, AeroMegt GmbH). The results presented here are an extension of the work by Zawadowicz et al (2015), who coupled a particle analysis by laser mass spectrometry (PALMS) with an fs laser (Spectra Physics Solstice-100F ultrafast laser) to investigate mass spectral patterns of NaCl, NH 4 NO 3 , and lead-doped NH 4 NO 3 particles. Overall, they observed similar mass spectra in both ns-and fs-laser ablation but also showed that ions with high ionization energy such as Cl + are more easily generated by the fs laser due to its higher power density.…”

Section: Introductionmentioning

confidence: 98%

“…Please note that for this work the geometry of ablation-ionization laser beam particle interaction was not orthogonal as for the experiments described by Zawadowicz et al (2015) but almost collinear, as this was favoured by the design of the LAAPTOF. Furthermore, we varied the power density of the ionization lasers by varying the laser energy and laser wavelength in the case of the fs laser (800 and 266 nm) and by changing the focus positions of the lasers.…”

Section: Introductionmentioning

confidence: 99%

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Exploring femtosecond laser ablation in single-particle aerosol mass spectrometry

et al. 2018

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Abstract. Size, composition, and mixing state of individual aerosol particles can be analysed in real time using singleparticle mass spectrometry (SPMS). In SPMS, laser ablation is the most widely used method for desorption and ionization of particle components, often realizing both in one single step. Excimer lasers are well suited for this task due to their relatively high power density (10 7 -10 10 W cm −2 ) in nanosecond (ns) pulses at ultraviolet (UV) wavelengths and short triggering times. However, varying particle optical properties and matrix effects make a quantitative interpretation of this analytical approach challenging. In atmospheric SPMS applications, this influences both the mass fraction of an individual particle that is ablated, as well as the resulting mass spectral fragmentation pattern of the ablated material. The present study explores the use of shorter (femtosecond, fs) laser pulses for atmospheric SPMS. Its objective is to assess whether the higher laser power density of the fs laser leads to a more complete ionization of the entire particle and higher ion signal and thus improvement in the quantitative abilities of SPMS. We systematically investigate the influence of power density and pulse duration on airborne particle (polystyrene latex, SiO 2 , NH 4 NO 3 , NaCl, and custom-made core-shell particles) ablation and reproducibility of mass spectral signatures. We used a laser ablation aerosol time-of-flight single-particle mass spectrometer (LAAPTOF, AeroMegt GmbH), originally equipped with an excimer laser (wavelength 193 nm, pulse width 8 ns, pulse energy 4 mJ), and coupled it to an fs laser (Spectra Physics Solstice-100F ultrafast laser) with similar pulse energy but longer wavelengths (266 nm with 100 fs and 0.2 mJ, 800 nm with 100 fs and 3.2 mJ). We successfully coupled the freefiring fs laser with the single-particle mass spectrometer employing the fs laser light scattered by the particle to trigger mass spectra acquisition. Generally, mass spectra exhibit an increase in ion intensities (factor 1 to 5) with increasing laser power density (∼ 10 9 to ∼ 10 13 W cm −2 ) from ns to fs laser. At the same time, fs-laser ablation produces spectra with larger ion fragments and ion clusters as well as clusters with oxygen, which does not render spectra interpretation more simple compared to ns-laser ablation. The idea that the higher power density of the fs laser leads to a more complete particle ablation and ionization could not be substantiated in this study. Quantification of ablated material remains difficult due to incomplete ionization of the particle. Furthermore, the fslaser application still suffers from limitations in triggering it in a useful time frame. Further studies are needed to test potential advantages of fs-over ns-laser ablation in SPMS.

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Section: Nh 4 No 3 Particlesmentioning

confidence: 65%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Exploring femtosecond laser ablation in single-particle aerosol mass spectrometry

et al. 2018

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“…The ns-LAAPTOF bipolar spectrum is comparable to the ammonium nitrate single particle spectrum obtained by the PALMS (Zawadowicz et al, 2015). NH4NO3 predominantly leads to positive ions (NH2 cluster ions are very high (Dunlap and Doyle, 1996), which may be the reason for the absence of these ions in the ns-spectra.…”

mentioning

confidence: 52%

“…The results presented here are an extension of the work by Zawadowicz et al (2015), who coupled a Particle Analysis by Laser Mass Spectrometry (PALMS) with an fslaser (Spectra Physics Solstice-100F ultrafast laser) to investigate mass spectral patterns of NaCl, NH4NO3, and lead doped NH4NO3 particles. Overall, they observed similar mass spectra in both ns-and fs-laser ablation, but 95 also showed that atoms with high ionization energy such as Cl are more easily ionized by the fs-laser due to its higher power density.…”

mentioning

confidence: 99%

Exploring femtosecond laser ablation in single particle aerosol mass spectrometry

Ramisetty¹,

Abdelmonem²,

Shen³

et al. 2017

Preprint

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Keywords: nanosecond laser ablation, femtosecond laser ablation, single particle mass spectrometry, atmospheric aerosols, aerosol mass spectrometry 10 AbstractSize, composition, and mixing state of individual aerosol particles can be analysed in real time using single particle mass spectrometry (SPMS). In SPMS, laser ablation is the most widely used method for desorption and ionization of particle components, often realizing both in one single step. Excimer lasers are well suited for this task due to their relatively high power density (10 7 W cm -2 -10 10 W cm -2 ) in nanosecond (ns) pulses at ultraviolet (UV) 15wavelengths, and short triggering times. However, varying particle optical properties and matrix effects make a quantitative interpretation of this analytical approach challenging. In atmospheric SPMS applications, this influences both the mass fraction of an individual particle that gets ablated, as well as the resulting mass spectral fragmentation pattern of the ablated material. The present study explores the use of shorter (femtosecond, fs) laser pulses for atmospheric SPMS, and systematically investigates the influence of power density and pulse duration 20 on airborne particle (polystyrene latex, SiO2, NH4NO3, NaCl, and custom-made core-shell particles) ablation and reproducibility of mass spectral signatures. We used a laser ablation aerosol time-of-flight single particle mass spectrometer (LAAPTOF, AeroMegt GmbH), originally equipped with an excimer laser (wavelength 193 nm, pulse width 8 ns, pulse energy 4 mJ), and coupled it to an fs-laser (Spectra Physics Solstice-100F ultrafast laser) with similar pulse energy, but longer wavelengths (266 nm with 100 fs and 0.2 mJ, 800 nm with 100 fs and 4 mJ, 25 respectively). Generally, mass spectra exhibit an increase in ion intensities (factor 1 to 5) with increasing laser power density (~10 8 W cm -2 to ~10 13 W cm -2) from ns-to fs-laser. At the same time, fs-laser ablation produces spectra with larger ion fragments and ion clusters, as well as clusters with oxygen, which does not render spectra interpretation more simple compared to ns-laser ablation. Quantification of ablated material remains difficult due to incomplete ionization of the particle. Furthermore, the fs-laser application still suffers from limitations in 30 triggering it in a useful timeframe. Further tests are needed to test potential advantages of fs-over ns-laser ablation in SPMS.

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Laser Ionization in Single‐Particle Mass Spectrometry

Passig

Zimmermann

2020

Photoionization and Photo‐Induced Processes in Mass Spectrometry

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Single-Particle Time-of-Flight Mass Spectrometry Utilizing a Femtosecond Desorption and Ionization Laser

Cited by 22 publications

References 42 publications

Exploring femtosecond laser ablation in single-particle aerosol mass spectrometry

Exploring femtosecond laser ablation in single-particle aerosol mass spectrometry

Exploring femtosecond laser ablation in single particle aerosol mass spectrometry

Laser Ionization in Single‐Particle Mass Spectrometry

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