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Comparison of some ambient aerosol samplers in combination with PIXE analysis
Author(s) -
Lannefors H.,
Carlsson L.E.
Publication year - 1983
Publication title -
x‐ray spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.447
H-Index - 45
eISSN - 1097-4539
pISSN - 0049-8246
DOI - 10.1002/xrs.1300120404
Subject(s) - aerosol , combustion , particulates , sampling (signal processing) , analytical chemistry (journal) , particle (ecology) , detection limit , mineralogy , filter (signal processing) , materials science , environmental science , chemistry , environmental chemistry , chromatography , oceanography , organic chemistry , computer science , computer vision , geology
PIXE (particle induced x‐ray emission) analysis of aerosols has been applied to four different samplers to determine sample thickness corrections, detection limits and required sampling times in different environments. The samplers (two total filter samplers, a two stage filter sampler and a cascade impactor) were used with filters made by Ghia, Millipore, Nucleopore and backings of polystyrene film, respectively. The calculations were based on the accumulation mode aerosol (particles in the 0.05–2μm diameter range) composition. Sampling times (resulting in detection limits 10 times lower than assumed aerosol concentrations) ranged from a quarter of an hour in urban, to a quarter of a day in rural and to two weeks in remote environments. These sampling times are calculated with the requirement that at least one element representing each of the following sources was detected: fossil fuel combustion (S, V and Ni), leaded petrol combustion (Br and Pb) and general industrial activities (Cr, Cu and Zn). Generally the two stage filter sampler employed with Nuclepore filters yielded the highest time resolution when specific flow rate, thickness and substrate impurities were taken into consideration. Thickness corrections based on a proton energy of 2.55 MeV and typical ambient urban and rural aerosol matrices show that elements of low atomic number such as P, S and Cl, where the x‐ray self absorption effect is most important, require a 10–20% correction with a uniform deposit thickness of about 0.5 mg cm −2 and a non‐nuniform (conical) deposit thickness of about 1 mg cm −2 . For elements of higher atomic number than vanadium (K x‐rays) the proton energy loss correction dominates. Sampling times resulting in the above mentioned deposit thicknesses were shortest for the cascade impactor while the Millipore and Nuclepore filter samplers were least critical in this respect.