Development of L-line x-ray fluorescence instrumentation and its applications to in-vivo measurement of lead in bone
- Albert Einstein College of Medicine, Bronx, NY (United States)
Initially, Wielopolski used x-rays from either a {sup 125}I or a {sup 109}Cd source to estimate lead (Pb) in tibial cortical bone in intact legs, postmortem, This system utilized the L{gamma} and L{Beta} x-rays of Ph with energies of 10.5 and 12.6 keV, respectively. The minimum detection limit (MDL) was considered to be comparable with existing K-line x-ray fluorescence (KXRF) instruments, namely, 20-30 ppm. The feasibility of partially polarized radiation was assessed from a {sup 125}I source on Pb (NO{sub 3}){sub 2}, (10,000 ppm) dissolved in water. Reduction of the detector total count rate was observed by a factor of two; and reduction in background by the same factor was appaent. This preliminary study suggested that, with proved design, the MDL might be lowered by a factor of five. A second post-mortem study was carried out using an {sup 125}I source. Tibial Pb concentration at the site of irradiation was subsequently measured by graphite furnace atomic absorption spectroscopy; the latter results ranged from 15 to 35 {mu}g Pb/g wet weight. The MDL for this instrument, calculated by multiplying the square root of background counts by a factor of 3, was estimated to be 22 ppm. The correlation coefficient between LXRF measurements and those carried out by atomic absorption was 0.90 (p < .03). In the same study, the use of a {sup 109}Cd source produced a higher degree of partial polarization with improvement in the sensitivity of the instrument. {sup 109}Cd was preferable, because its photoelectric cross section is higher than that of {sup 125}I.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 369857
- Report Number(s):
- CONF-9408178-; ISSN 0376-0308; TRN: 96:004756-0060
- Journal Information:
- Advances in X-Ray Analysis, Vol. 38; Conference: 43. annual Denver x-ray conference on applications of x-ray analysis, Steamboat Spring, CO (United States), 1-5 Aug 1994; Other Information: PBD: 1995
- Country of Publication:
- United States
- Language:
- English
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