EDXRF fluorescence

Table 8.39 Main features of energy-dispersive X-ray fluorescence spectrometry (EDXRF)...

Both WDXRF and EDXRF lend themselves admirably to quantitative analysis, since there is a relationship between the wavelength or energy of a characteristic X-ray photon and the atomic number of the element from which the characteristic emission line occurs. The fluorescence intensity of a given element is proportional to the weight fraction. Emitted fluorescence radiation is partly absorbed by the matrix, depending on the total mass absorption coefficient ... 

Fluorescence, 3 256 22 716. See also EDXRF instruments Micro X-ray fluorescence (MXRF) analysis Total reflection X-ray fluorescence spectrometry micro X-ray, 26 437-439 Raman scattering and, 21 324, 325 sensors using, 22 271... 

Figure 5.5 Comparison of EDXRF and WDXRF detection systems. Fluorescent X-rays are emitted by the sample on the left. The upper line shows a wavelength dispersive XRF system the lower shows an energy dispersive system. (Reproduced from Pollard and Heron 1996 44, by permission of the Royal Society of Chemistry.)...

Danesi et al.96 applied SIMS, in addition to X-ray fluorescence imaging, by using a microbeam (p-XRF) and scanning electron microscope equipped with an energy dispersive X-ray fluorescence analyzer (SEM-EDXRF) to characterize soil samples and to identify small DU particles collected in Kosovo locations where depleted uranium (DU) ammunition was employed during the 1999 Balkan conflict. Knowledge of DU particles is needed as a basis for the assessment of the potential environmental and health impacts of military use of DU, since it provides information on possible resuspension and inhalation. The measurements indicated spots where hundreds of thousands of particles may be present in a few mg of contaminated soil. The particle size distribution showed that most of the DU particles were < 5 pm in diameter and more than 50 % of the particles had a diameter of < 1.5 p.m.96... 

Enamel and bone, strontium isotope analysis, 102-104 Energy dispersive spectrometry (EDS), scanning electron microscopy, Seip textiles, 35 Energy dispersive X-ray fluorescence (EDXRF), elemental analyses copper-based coins, 231-245 copper coins, Herodian prutah, 246-257... 

Energy dispersive X-ray fluorescence (EDXRF) spectroscopy is used to determine which chemicals are... 

Nowadays, iodine is measured using inductively coupled plasma mass spectrometry (ICP-MS) and energy-dispersive X-ray fluorescence analysis of iodine (EDXRF) (Zaichick and Zaichick 1999). The detection limit of iodine is 3 Jigg for 30-minute measurements of 10-15 mg specimens of fresh tissues, and 10-minute measurements of40- 60 specimens of homogenized dry tissues. 

X-ray fluorescence (energy dispersive, EDXRF wavelength dispersive, WDXRF)... 

Human and animal blood and plasma. Human Blood Plasma RM (Versieck) As Br Cd Ca Cl Co Cu 1 Fe Pb Mn Mo Ni Se Sn Zn Microwave ashing System pj DM] Analyze with energy dispersive X- [WDM-EDXRF] ray fluorescence spectrometer with total reflection optics [EDTXRF] Savage and Haswell 1998... 

A micro-adaptation of energy dispersive X-ray fluorescence (EDXRF) has been used to compare the Ni content of normal and carcinomatous human breast tissue (Rizk and Sky-Peck, 1984). Surgical specimens were homogenized (200 g/L in water) in a Teflon homogenizer. Ten 5 aliquots of each specimen were layered onto Formvar films in a slide holder, air-dried under laminar flow, and placed in the vacuum chamber of the instrument at 200 /im of mercury. By X-irradiation for 500 s (18 mA, 35 kV) 16 elements were determined simultaneously. The Ni scattered peak was observed at 7 keV and Ni concentrations of about 1 mg/kg dry wt. were caiculated after computer correction of the background continuum, as described (Sky-Peck and Joseph, 1981). 

With proper correction for matrix effects. X-ray fluorescence spectrometry is one of the most powerful tools available for the rapid quantitative determination of all but the lightest elements in complex samples. For example. Rose, Bornhorst. and Sivonon have demonstrated that twenty-two elements can bo determined in powdered rock samples with a commercial EDXRF spectrometer in about 2 hours (1 hour instrument time), including grinding and pellet preparation. Relative standard deviations for the method are better than 1% for major elements and better than y/o for trace elements. Accuracy and detection limits as determined by comparison to results from international standard rock samples were comparable or better than other published procedures. For an e.xcellent overview of XRF analysis of geological materials, see the paper by Anzelmo and Lindsay. ... 

X-ray Fluorescence (XRF) is a common technique for sulfur determination in hydrocarbon oils. At-line and laboratory XRF analysis is covered in the ASTM standard test methods for sulfur in petroleum products ASTM Standard Method D 4294 (for Energy Dispersive XRF, EDXRF) [1] and ASTM Standard Method D 2622 (for Wavelength Dispersive XRF, WDXRF) [2]. Polarized EDXRF [3] is also used at-line for the determination of very low sulfur content (<10 ppm sulfur) in diesel and gasoline fuels. 

Numerous techniques and instrumental methods can be used to measure sulfur in gasoline and diesel fuels [3]. It is beyond the scope of this paper to cover any of the standard techniques in detail. Unfortunately, many of the traditionally used techniques are out of consideration for analyzing fuels at low levels because of inadequate sensitivity or lack of precision at those levels. For instance, a study group comprised of 69 industry participants has recommended that Energy Dispersive X-ray Fluorescence (EDXRF) and some other older technologies be dropped fi-om consideration for analyzing fuels at the 30 ppm level [3],... 

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