What are the instruments for the ground measurements of aerosols and which sizes are you considering in your measurements? In case of air sampling, which filters are being used by you?
Dear Dr Nawab Ali ;
In this comment, I will make a sampling protocol of PM10, which I was used in some of my work. Wish that can help you...
"Aerosol sampling was performed at 3 m above the
ground level by a total filtration of the air using
nucleopore filters, characterized by a diameter and a
porosity of 4.7 cm and 0.45 μm, respectively. The
threshold aerodynamic diameter of the aerosol sampler
nozzle is 10 μm. Aerosol sampling was performed on a
daily basis at an hourly rate of 180 l. The collected
samples were analysed by wavelength X-ray florescence
spectrometry. Each sample was counted twice
K-alpha (or L-beta Pb lines) and PGFD or CS detectors
with 3 kW Siemens SRS 303 spectrometer and Rh tube.
According to the procedure described by Quisefit et al.
(1996), the concentrations (expressed in μg/m3) of 11
chemical elements (Cl, Na, Si, Al, Ca, Fe, Mg, Mn, Pb,
Zn, S) "
And what do you do with the chemical data with respect to light-scattering ?
The measurement technique depends on the objective of sampling. If source apportionment study is the objective, then sampling of PM10 and PM2.5 should be carried out. The sample should be collected on Teflon filter for elemental analysis. This requires use of XRF in lab for elemental analysis. Ions can be analysed using IC.
If elemental Carbon and Organic Carbon is to be studied, EC/OC analyser of DRI should be used and the Pm sample should be collected on pre-baked quartz filter.
If secondary pollutant nitrate is to be studied, the Pm should be collected on Nylon filter.
If objective is only measurement of PM10 and PM2.5 without any chemical speciation, then Beta Attenuation Monitor (BAM) or any other similar equipment can be used, which gives the data but not he physical sample
A more comprehensive characterization comes from sampling with cascade impactors from which the mass distribution and composition per size interval is obtained
Eight stage Cascade impactor collects PM in different size fractions from 10 micro meter to 0.4 micro meter. The collected particles are in small dots, which can be seen and analysed by SEM-EDX only. The small quantity of collected PM does not permit it to use other destructive techniques for chemical speciation. Use of particle size distribution is explained in a paper titled:
George, K.V., D.D. Patil, M.N.V. Anil, Neel Kamal, B.J. Alappat, Prashant Kumar (2016). Evaluation of coarse and fine particles in diverse Indian environment. Environmental Science and Pollution Research. DOI 10.1007/s11356-016-8049-3.
Kariam
Cascade impactors run at a very high air rate and DO permit classical chemical analysis of the collected material with Ion Chromatography and AAS/AES for all inorganics and also analysis of carbon when using aluminum foil substrates
There are thousands of publications with results?!
Dear Harry, may I request you to kindly indicate some references related to chemical analysis of PM collected on cascade impactor? This will help me in my forthcoming field work on SA studies. Is there any supplier of cascade impactor of high volume. The one which I used was of 28.3 LPM.
@Kariam
The 1 cfm is more than sufficient for classical chemical analysis
Is this an Andersen impactor? We have used this since the end of the seventies; we also used Berner impactors
Composition/size of the light-scattering aerosol in the NetherlandsTen Brink, H. M.; Kruisz, C.; Kos, G. P. A.; Berner, A.
Atmospheric Environment, 31, 3955-3962.
More recently we have the "MOUDI" or rather the classical MOI; there is also a version with a flow close to 100 LPM
http://www.mspcorp.com/aerosol-instruments/model-130-high-flow-impactor/
and then there is thisthenhttps://www.researchgate.net/profile/Oliver_Chang/publication/244247630_Field_evaluation_of_a_mobile_high-capacity_particle_size_classifier_HCPSC_for_separate_collection_of_coarse_fine_and_ultrafine_particles/links/553fc9ad0cf2736761c2589b.pdf
Article Field evaluation of a mobile high-capacity particle size cla...
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