Atmospheric particulate analysis by synchrotron radiation total reflection (SR‐TXRF)

Abstract

X-ray fluorescence with synchrotron radiation total reflection was used to analyze the atmospheric particulate collected in Campinas, SP, Brazil, in fine and coarse fractions, using a stacked filter unit. After treatment with acid solution and pipetting on to Perspex disks, the samples were measured at the x-ray fluorescence beamline at the National Synchrotron Light Laboratory (LNLS), Campinas, using a polychromatic beam for sample excitation. The detection limits obtained ranged from 0.3 to 8.9 ng m −3 for the majority of the elements. The data obtained were treated using analysis receptor models of the principal components, then absolute principal component analysis was applied to obtain the contribution of each source to the total of both particulate fractions. Four sources were identified for the fine fraction for autumn/winter and summer periods: (1) soil dust (22 and 29%); (2) industry (26 and 23%); (3) sulfate (23 and 20%); (4) motor vehicle (22 and 20%); and 7% and 8% non-explained, in the autumn/winter and summer periods, respectively. In coarse fraction analysis, two sources were identified for the autumn/winter and summer periods and with similar rates for source contribution. The obtained sources were: (1) soil dust (77 and 78%); (2) industry (18 and 16%); and non-explained rates of 5 and 6%, in the autumn/winter and summer periods, respectively.

Study of main and signature sources of particulate matter pollutants in Limeira City (Brazil) using SR‐TXRF

“…The MDL was calculated by Eqn () where l i is the signal intensity of element i in the sample, I y is the signal intensity of the internal standard ( Y ) in the sample, C y is the concentration of the internal standard ( Y ) in the sample, S Ri is the relative sensitivity for element i , BG corresponds to the background signal intensity (counts per second), and t is time in seconds.…”

“…The key elements for each source were determined on the basis of data from the literature . On the basis of the elemental concentrations of the two fractions and on the values obtained for each element in the factor loadings matrices, we can calculate the contribution of each emission source to the formation of the CPM and FPM fractions.…”

“…The air inlet was installed 2.15 m high above the soil by using 47‐mm‐diameter polycarbonate filters. For the collection of particles with aerodynamic diameters between 2.5 and 10 µm (coarse fraction), 8‐µm pore diameter filters were used, whereas for the fine fraction (particles of aerodynamic diameter smaller than 2.5 µm), 0.4‐µm pore diameter filters were used . The impact of particles on the filter itself was taken into consideration in selecting filters with these specific porosities, thereby preventing filter clogging and ensuring retention of the desired particles on each filter .…”

“…One of the growing problems of metropolitan areas around the word is air pollution . Accelerated population growth of small urban centers, in addition to industrial and transportation expansion without adequate planning, has contributed to the elevations in air pollution indices …”

X-Ray Fluorescence Spectrometry

“…A high-resolution and highefficiency Si(Li) or HPGe detector may be employed. Typical detection limits (DL) calculated on the basis of three times the square root of the background are listed in Table 9 [45,46]. EDXRF spectrometers, also in the form of portable equipment, have been also widely employed to analyze water (rain water, drinking water, mineral water, polluted water), generally in the form of dry residues [46][47][48][49].…”