Elemental characterization of airborne particles in Khartoum, Sudan

Abstract

The aim of this study was to investigate the elemental composition of airborne particles in the Khartoum area, particularly small inhalable particles of diameter ≤10 µm. Aerosol particles were collected during the period April–May 2001. The sampling was done using a dichotomous virtual impactor capable of separating airborne particles <2.5 µm in a fine mode and 2.5–10 µm particles in a coarse mode. Energy‐dispersive x‐ray fluorescence analysis was used to determine the elemental concentrations of 14 elements in the samples. Concentrations of black carbon were also measured on the two size fractions. The results obtained were compared with previous data from Khartoum and other African locations. Si, K, Ca, Ti, Mn, Fe, Zn and Sr were found to be dominant in the collected particulates. Day period collections were found to have higher elemental concentrations than those of night periods. This is attributed to higher traffic levels and wind speeds. The results show that dust aerosol transport and resuspension are the main sources that affect the quality of ambient air in the Khartoum area. The elemental concentrations from anthropogenic sources are generally low. Copyright © 2004 John Wiley & Sons, Ltd.

Optimization of Measurement Conditions of an Energy Dispersive X-Ray Fluorescence Spectrometer with High-Energy Polarized Beam Excitation for Analysis of Aerosol Filters

“…At the same time, the DLs obtained on the ''Epsilon 5'' for the light elements (Si through Cl) were found to be significantly lower than the results obtained on another three-axial EDXRF instrument. [11][12][13] For the elements ranging from V to Zn, the results obtained on the ''Epsilon 5'' and the instruments used in Refs. 11-13 are similar although a two times more powerful tube was used in the latter cases.…”

“…The instrument used is not commercially available, but was built at the Department of Environmental Physics at the Chalmers University of Technology, Götenborg, Sweden. El-Tahir et al 12 also employed this spectrometer with the same measurement conditions to examine airborne particles in Khartoum, Sudan. Bennet et al 13 investigated particulate air pollution in Dar Es Salaam, Tanzania, applying a W-anode operating at 55 kV and 25 mA on this equipment and a Mo secondary target.…”

Determination of elemental composition of air particulates and soils in Khartoum area

“…2 shows a typical spectrum of the fine particles in the background aerosols of Khartoum city. Details of the analysis procedure of the air particulates are described elsewhere (Eltahir et al 2005). The data from the Cd-109 spectrometer system were converted to Pb concentrations using a calibration obtained by use of standard solutions of lead compounds.…”

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].…”