Characteristics and sources of ambient refractory black carbon aerosols: Insights from soot particle aerosol mass spectrometer

Abstract. The soot-particle aerosol mass spectrometer (SP-AMS) uses an intra-cavity infrared laser to vaporize refractory black carbon (rBC) containing particles, making the particle beam–laser beam overlap critical in determining the collection efficiency (CE) for rBC and associated non-refractory particulate matter (NR-PM). This work evaluates the ability of the SP-AMS to quantify rBC and NR-PM mass in internally mixed particles with different thicknesses of organic coating. Using apparent relative ionization efficiencies for uncoated and thickly coated rBC particles, we report measurements of SP-AMS sensitivity to NR-PM and rBC, for Regal Black, the recommended particulate calibration material. Beam width probe (BWP) measurements are used to illustrate an increase in sensitivity for highly coated particles due to narrowing of the particle beam, which enhances the CE of the SP-AMS by increasing the laser beam–particle beam overlap. Assuming complete overlap for thick coatings, we estimate CE for bare Regal Black particles of 0.6 ± 0.1, which suggests that previously measured SP-AMS sensitivities to Regal Black were underestimated by up to a factor of 2. The efficacy of the BWP measurements is highlighted by studies at a busy road in downtown Toronto and at a non-roadside location, which show particle beam widths similar to, but greater than that of bare Regal Black and coated Regal Black, respectively. Further BWP measurements at field locations will help to constrain the range of CE for fresh and aged rBC-containing particles. The ability of the SP-AMS to quantitatively assess the composition of internally mixed particles is validated through measurements of laboratory-generated organic coated particles, which demonstrate that the SP-AMS can quantify rBC and NR-PM over a wide range of particle compositions and rBC core sizes.

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Supplementary material to "Elemental analysis of Oxygenated Organic Coating on Black Carbon Particles using a Soot-Particle Aerosol Mass Spectrometer"

10.5194/amt-2020-303-supplement ◽

2020 ◽

Author(s):

Mutian Ma ◽

Laura-Hélèna Rivellini ◽

YuXi Cui ◽

Megan D. Willis ◽

Rio Wilkie ◽

...

Keyword(s):

Black Carbon ◽

Mass Spectrometer ◽

Elemental Analysis ◽

Soot Particle ◽

Organic Coating ◽

Aerosol Mass Spectrometer ◽

Carbon Particles ◽

Aerosol Mass ◽

Supplementary Material

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Elemental analysis of Oxygenated Organic Coating on Black Carbon Particles using a Soot-Particle Aerosol Mass Spectrometer

10.5194/amt-2020-303 ◽

2020 ◽

Author(s):

Mutian Ma ◽

Laura-Hélèna Rivellini ◽

YuXi Cui ◽

Megan D. Willis ◽

Rio Wilkie ◽

...

Keyword(s):

Black Carbon ◽

Mass Spectrometer ◽

Elemental Analysis ◽

Soot Particle ◽

Organic Coatings ◽

Laser Vaporization ◽

Scaling Factors ◽

Aerosol Mass Spectrometer ◽

Aerosol Mass ◽

Relative Errors

Abstract. Chemical characterization of organic coatings is important to advance our understanding of the physio-chemical properties and environmental fate of black carbon (BC) particles. The soot-particle aerosol mass spectrometer (SP-AMS) has been utilized for this purpose in recent field studies. The laser vaporization (LV) scheme of SP-AMS can heat BC cores gradually until they are completely vaporized, during which organic coatings can be vaporized at temperatures lower than that of the thermal vaporizer (TV) used in a standard high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) that employs flash vaporization. This work investigates the effects of vaporization schemes on fragmentation and elemental analysis of known oxygenated organic species using three SP-AMS instruments. We show that LV can reduce fragmentation of organic molecules. Substantial enhancement of C2H3O+/CO2+ and C2H4O2+ signals was observed for most of the tested species when the LV scheme was used, suggesting that the observational frameworks based using HR-ToF-AMS field data may not be directly applicable for evaluating the chemical evolution of oxygenated organic aerosol (OOA) components coated on ambient BC particles. The uncertainties of H:C and O:C determined by the improved-ambient (I-A) method for both LV and TV approaches were similar, with scaling factors of 1.10 for H:C and 0.89 for O:C were determined to facilitate more direct comparisons between observations from the two vaporization schemes. Furthermore, the I-A method was updated based on the multilinear regression model for the LV scheme measurements. The updated parameters can reduce the relative errors of O:C from −26.3 % to 5.8 %, whereas the relative errors of H:C remain roughly the same. Applying the scaling factors and the updated parameters for the I-A method to ambient data, we found that even though the time series of OOA components determined by the LV and TV schemes are strongly correlated at the same location, OOA coatings were likely less oxygenated compared to those externally mixed with BC.

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Influence of Emissions and Aqueous Processing on Particles Containing Black Carbon in a Polluted Urban Environment: Insights From a Soot Particle-Aerosol Mass Spectrometer

Journal of Geophysical Research Atmospheres ◽

10.1002/2017jd027851 ◽

2018 ◽

Vol 123 (12) ◽

pp. 6648-6666 ◽

Cited By ~ 11

Author(s):

Sonya Collier ◽

Leah R. Williams ◽

Timothy B. Onasch ◽

Christopher D. Cappa ◽

Xiaolu Zhang ◽

...

Keyword(s):

Urban Environment ◽

Black Carbon ◽

Mass Spectrometer ◽

Soot Particle ◽

Aqueous Processing ◽

Aerosol Mass Spectrometer ◽

Aerosol Mass

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Collection efficiency of the Soot-Particle Aerosol Mass Spectrometer (SP-AMS) for internally mixed particulate black carbon

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-5223-2014 ◽

2014 ◽

Vol 7 (5) ◽

pp. 5223-5249 ◽

Cited By ~ 4

Author(s):

M. D. Willis ◽

A. K. Y. Lee ◽

T. B. Onasch ◽

E. C. Fortner ◽

L. R. Williams ◽

...

Keyword(s):

Laser Beam ◽

Black Carbon ◽

Mass Spectrometer ◽

Soot Particle ◽

Collection Efficiency ◽

Particle Beam ◽

Aerosol Mass Spectrometer ◽

Coated Particles ◽

Aerosol Mass ◽

Wide Range

Abstract. The soot-particle aerosol mass spectrometer (SP-AMS) uses an intra-cavity infrared laser to vaporize refractory black carbon (rBC) containing particles, making the particle beam–laser beam overlap critical in determining the collection efficiency (CE) for rBC and associated non-refractory particulate matter (NR-PM). This work evaluates the ability of the SP-AMS to quantify rBC and NR-PM mass in internally mixed particles with different thicknesses of organic coating. Using apparent relative ionization efficiencies for uncoated and thickly coated rBC particles, we report measurements of SP-AMS sensitivity to NR-PM and rBC, for Regal Black, the recommended particulate calibration material. Beam width probe (BWP) measurements are used to illustrate an increase in sensitivity for highly coated particles due to narrowing of the particle beam, which enhances the CE of the SP-AMS by increasing the laser beam–particle beam overlap. Assuming complete overlap for thick coatings, we estimate CE for bare Regal Black particles of 0.6 ± 0.1, which suggests that previously measured SP-AMS sensitivities to Regal Black were underestimated by up to a factor of two. The efficacy of the BWP measurements is highlighted by studies at a busy road in downtown Toronto and at a non-roadside location, which show particle beam widths similar to, but greater than that of bare Regal Black and coated Regal Black, respectively. Further BWP measurements at field locations will help to constrain the range of CE for fresh and aged rBC-containing particles. The ability of the SP-AMS to quantitatively assess the composition of internally mixed particles is validated through measurements of laboratory-generated organic coated particles, which demonstrate that the SP-AMS can quantify rBC and NR-PM over a wide range of particle compositions and rBC core sizes.

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Characterization of black carbon-containing particles from soot particle aerosol mass spectrometer measurements on the R/VAtlantisduring CalNex 2010

Journal of Geophysical Research Atmospheres ◽

10.1002/2014jd022834 ◽

2015 ◽

Vol 120 (6) ◽

pp. 2575-2593 ◽

Cited By ~ 25

Author(s):

Paola Massoli ◽

Timothy B. Onasch ◽

Christopher D. Cappa ◽

Ibraheem Nuamaan ◽

Jani Hakala ◽

...

Keyword(s):

Black Carbon ◽

Mass Spectrometer ◽

Soot Particle ◽

Aerosol Mass Spectrometer ◽

Aerosol Mass

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Technical Note: A new approach to discriminate different black carbon sources by utilising fullerenes and metals in Positive Matrix Factorisation analysis of High-Resolution Soot Particle Aerosol Mass Spectrometer data

10.5194/acp-2020-890 ◽

2020 ◽

Author(s):

Zainab Bibi ◽

Hugh Coe ◽

James Brooks ◽

Paul I. Williams ◽

Ernesto Reyes-Villegas ◽

...

Keyword(s):

High Resolution ◽

Human Health ◽

Black Carbon ◽

Source Apportionment ◽

Mass Spectrometer ◽

Atmospheric Aerosol ◽

Soot Particle ◽

Positive Matrix ◽

Aerosol Mass Spectrometer ◽

Aerosol Mass

Abstract. Atmospheric aerosol particles are known to have detrimental effects on human health and climate. Black carbon is an important constituent of atmospheric aerosol particulate matter (PM), emitted from the incomplete combustion process and cause significant effects on the air quality and human health. Source apportionment of BC is very important, to identify the fraction of BC that has an anthropogenic origin and to evaluate the influence of different sources. The High-Resolution Soot Particle Aerosol Mass Spectrometer (HR-SP-AMS) instrument uses a laser vaporizer, which allows the real-time detection and characterization of refractory BC and its internally mixed particles such as metals, coating species and rBC subcomponent in the form of fullerene. In this case study, the soot data was collected by using HR-SP-AMS during Guy Fawkes Night on 5th of November 2014. Positive matrix factorization (PMF) was applied in order to positively discriminate between different wood-burning sources for the first time, in this case, BC from domestic wood-burning and bonfires, which no existing black carbon source apportionment technique is currently able to do. Along with this, the use of the fullerene signals in differentiating between soot sources and the use of metals as a tracer for fireworks has also been investigated, which has not significantly contributed to the BC concentrations. The addition of fullerenes signals and successful application of PMF on SP-AMS data apportioned BC into more than two sources. These bonfire sources are hydrocarbon-like Fullerenes, biomass burning organic aerosol, HULIS (humic-like substance) and non-bonfire sources such as hydrocarbon-like OA and domestic burning. The result of correlation analysis between HR-SP-AMS data with previously published Aethalometer, MAAP and CIMS data provides an effective way of quickly gaining insights in relations between the variables and also provide a quantitative estimate of the source contributions to the BC budget during this period. This research study is an important demonstration of using HR-SP-AMS for the purpose of BC source apportionment.

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Elemental analysis of oxygenated organic coating on black carbon particles using a soot-particle aerosol mass spectrometer

Atmospheric Measurement Techniques ◽

10.5194/amt-14-2799-2021 ◽

2021 ◽

Vol 14 (4) ◽

pp. 2799-2812

Author(s):

Mutian Ma ◽

Laura-Hélèna Rivellini ◽

YuXi Cui ◽

Megan D. Willis ◽

Rio Wilkie ◽

...

Keyword(s):

Black Carbon ◽

Mass Spectrometer ◽

Elemental Analysis ◽

Soot Particle ◽

Organic Coatings ◽

Laser Vaporization ◽

Scaling Factors ◽

Aerosol Mass Spectrometer ◽

Aerosol Mass ◽

Relative Errors

Abstract. Chemical characterization of organic coatings is important to advance our understanding of the physio-chemical properties and environmental fate of black carbon (BC) particles. The soot-particle aerosol mass spectrometer (SP-AMS) has been utilized for this purpose in recent field studies. The laser vaporization (LV) scheme of the SP-AMS can heat BC cores gradually until they are completely vaporized, during which organic coatings can be vaporized at temperatures lower than that of the thermal vaporizer (TV) used in a standard high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) that employs flash vaporization. This work investigates the effects of vaporization schemes on fragmentation and elemental analysis of known oxygenated organic species using three SP-AMS instruments. We show that LV can reduce fragmentation of organic molecules. Substantial enhancement of C2H3O+/CO2+ and C2H4O2+ signals was observed for most of the tested species when the LV scheme was used, suggesting that the observational frameworks based on the use of HR-ToF-AMS field data may not be directly applicable for evaluating the chemical evolution of oxygenated organic aerosol (OOA) components coated on ambient BC particles. The uncertainties of H:C and O:C determined using the improved-ambient (I-A) method for both LV and TV approaches were similar, and scaling factors of 1.10 for H:C and 0.89 for O:C were determined to facilitate more direct comparisons between observations from the two vaporization schemes. Furthermore, the I-A method was updated based on the multilinear regression model for the LV scheme measurements. The updated parameters can reduce the relative errors of O:C from −26.3 % to 5.8 %, whereas the relative errors of H:C remain roughly the same. Applying the scaling factors and the updated parameters for the I-A method to ambient data, we found that even though the time series of OOA components determined using the LV and TV schemes are strongly correlated at the same location, OOA coatings were likely less oxygenated compared to those externally mixed with BC.

Download Full-text