scholarly journals Size Distributions of Gold Nanoparticles in Solution Measured by Single-Particle Mass Photometry

2021 ◽  
Author(s):  
Luke Melo ◽  
Angus Hui ◽  
Matt Kowal ◽  
Eric Boateng ◽  
Zahra Poursorkh ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Single Particle ◽  
Particle Mass ◽  
Size Distributions

Characterization of vertical aerosol flows by single particle mass spectrometry for micrometeorological analysis

2011 ◽  
Vol 102 (1-2) ◽  
pp. 49-56 ◽  
Author(s):  
Elmar Gelhausen ◽  
Klaus-Peter Hinz ◽  
Andres Schmidt ◽  
Bernhard Spengler
Keyword(s):  
Mass Spectrometry ◽  
Single Particle ◽  
Particle Mass ◽  
Single Particle Mass Spectrometry

A stochastic model for sand sorting in a wind-tunnel

1981 ◽  
Vol 13 (2) ◽  
pp. 282-297 ◽  
Author(s):  
O. Barndorff-Nielsen ◽  
J. N. Darroch
Keyword(s):  
Wind Tunnel ◽  
Stochastic Model ◽  
Single Particle ◽  
Hyperbolic Type ◽  
Size Distributions ◽  
Wind Tunnel Experiments ◽  
Stable Conditions ◽  
Hyperbolic Form ◽  
Experimental Findings

The wind exerts a sorting effect on particles of sands and, under certain stable conditions that occur frequently but whose nature is little understood, the sorting results in log-size distributions of the hyperbolic form, first noted by R. A. Bagnold. Here, for wind-tunnel experiments a stochastic model is constructed which exhibits a sorting effect deriving from the dependence of distance travelled on the size of the single particle. Under rather specific, experimentally testable assumptions the model reproduces log-size distributions which are of the hyperbolic type and show a variation with distance along the wind tunnel that accords with experimental findings of R. A. Bagnold.

scholarly journals Sources and mixing state of size-resolved elemental carbon particles in a European megacity: Paris

2012 ◽  
Vol 12 (4) ◽  
pp. 1681-1700 ◽  
Author(s):  
R. M. Healy ◽  
J. Sciare ◽  
L. Poulain ◽  
K. Kamili ◽  
M. Merkel ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Biomass Burning ◽  
Single Particle ◽  
Mass Concentration ◽  
Elemental Carbon ◽  
Fossil Fuel ◽  
Time Of Flight ◽  
Particle Mass ◽  
Mass Size ◽  
Mass Concentrations

Abstract. An Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) was deployed to investigate the size-resolved chemical composition of single particles at an urban background site in Paris, France, as part of the MEGAPOLI winter campaign in January/February 2010. ATOFMS particle counts were scaled to match coincident Twin Differential Mobility Particle Sizer (TDMPS) data in order to generate hourly size-resolved mass concentrations for the single particle classes observed. The total scaled ATOFMS particle mass concentration in the size range 150–1067 nm was found to agree very well with the sum of concurrent High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and Multi-Angle Absorption Photometer (MAAP) mass concentration measurements of organic carbon (OC), inorganic ions and black carbon (BC) (R2 = 0.91). Clustering analysis of the ATOFMS single particle mass spectra allowed the separation of elemental carbon (EC) particles into four classes: (i) EC attributed to biomass burning (ECbiomass), (ii) EC attributed to traffic (ECtraffic), (iii) EC internally mixed with OC and ammonium sulfate (ECOCSOx), and (iv) EC internally mixed with OC and ammonium nitrate (ECOCNOx). Average hourly mass concentrations for EC-containing particles detected by the ATOFMS were found to agree reasonably well with semi-continuous quantitative thermal/optical EC and optical BC measurements (r2 = 0.61 and 0.65–0.68 respectively, n = 552). The EC particle mass assigned to fossil fuel and biomass burning sources also agreed reasonably well with BC mass fractions assigned to the same sources using seven-wavelength aethalometer data (r2 = 0.60 and 0.48, respectively, n = 568). Agreement between the ATOFMS and other instrumentation improved noticeably when a period influenced by significantly aged, internally mixed EC particles was removed from the intercomparison. 88% and 12% of EC particle mass was apportioned to fossil fuel and biomass burning respectively using the ATOFMS data compared with 85% and 15% respectively for BC estimated from the aethalometer model. On average, the mass size distribution for EC particles is bimodal; the smaller mode is attributed to locally emitted, mostly externally mixed EC particles, while the larger mode is dominated by aged, internally mixed ECOCNOx particles associated with continental transport events. Periods of continental influence were identified using the Lagrangian Particle Dispersion Model (LPDM) "FLEXPART". A consistent minimum between the two EC mass size modes was observed at approximately 400 nm for the measurement period. EC particles below this size are attributed to local emissions using chemical mixing state information and contribute 79% of the scaled ATOFMS EC particle mass, while particles above this size are attributed to continental transport events and contribute 21% of the EC particle mass. These results clearly demonstrate the potential benefit of monitoring size-resolved mass concentrations for the separation of local and continental EC emissions. Knowledge of the relative input of these emissions is essential for assessing the effectiveness of local abatement strategies.

scholarly journals Single Particle Soot Photometer intercomparison at the AIDA chamber

2012 ◽  
Vol 5 (12) ◽  
pp. 3077-3097 ◽  
Author(s):  
M. Laborde ◽  
M. Schnaiter ◽  
C. Linke ◽  
H. Saathoff ◽  
K.-H. Naumann ◽  
...  
Keyword(s):  
Single Particle ◽  
Detection Efficiency ◽  
Particle Morphology ◽  
Ambient Air ◽  
Mass Range ◽  
Size Distributions ◽  
Position Measurement ◽  
Fullerene Soot ◽  
Mass Size ◽  
Calibration Material

Abstract. Soot particles, consisting of black carbon (BC), organic carbon (OC), inorganic salts, and trace elements, are emitted into the atmosphere during incomplete combustion. Accurate measurements of atmospheric BC are important as BC particles cause adverse health effects and impact the climate. Unfortunately, the accurate measurement of the properties and mass concentrations of BC particles remains difficult. The Single Particle Soot Photometer (SP2) can contribute to improving this situation by measuring the mass of refractory BC in individual particles as well as its mixing state. Here, the results of the first detailed SP2 intercomparison, involving 6 SP2s from 6 different research groups, are presented, including the most evolved data products that can presently be calculated from SP2 measurements. It was shown that a detection efficiency of almost 100% down to 1 fg BC per particle can readily be achieved, and that this limit can be pushed down to ∼0.2 fg BC with optimal SP2 setup. Number and mass size distributions of BC cores agreed within ±5% and ±10%, respectively, in between the SP2s, with larger deviations in the range below 1 fg BC. The accuracy of the SP2's mass concentration measurement depends on the calibration material chosen. The SP2 has previously been shown to be equally sensitive to fullerene soot and ambient BC from sources where fossil fuel was dominant and less sensitive to fullerene soot than to Aquadag. Fullerene soot was therefore chosen as the standard calibration material by the SP2 user community; however, many data sets rely solely on Aquadag calibration measurements. The difference in SP2 sensitivity was found to be almost equal (fullerene soot to Aquadag response ratio of ∼0.75 at 8.9 fg BC) for all SP2s. This allows the calculation of a fullerene soot equivalent calibration curve from a measured Aquadag calibration, when no fullerene soot calibration is available. It could be shown that this approach works well for all SP2s over the mass range of 1–10 fg. This range is suitable for typical BC mass size distributions in the ambient air far from sources. The number size distribution of purely scattering particles optically measured by the 6 SP2s also agreed within 15%. Measurements of the thickness of non-refractory coatings (i.e. product from α-pinene ozonolysis) on the BC particles, relying on BC mass optical size and on an additional particle position measurement, also compared well (within ±17%). The estimated coating thickness values were consistent with thermo-optical analysis of OC and elemental carbon (EC) content, though absolutely accurate values cannot be expected given all the assumptions that have to be made regarding refractive index, particle morphology, etc. This study showed that the SP2 provides accurate and reproducible data, but also that high data quality is only achieved if the SP2 is carefully tuned and calibrated. It has to be noted that the agreement observed here does not account for additional variability in output data that could result from the differences in the potentially subjective assumptions made by different SP2 users in the data processing.

Sign in / Sign up

Export Citation Format

Share Document