Limits of detection of a total reflection X-ray fluorescence system with double reflection module.
Biol Trace Elem Res
; 71-72: 423-30, 1999.
Article
en En
| MEDLINE
| ID: mdl-10676518
ABSTRACT
An X-ray tube with a Mo target and Zr filter, operated at 45 kV/20 mA, was used to excite samples (5 microL deposited on a quartz support) and the total reflection angle condition was obtained with a double reflector module built with two 10-cm-long 7-mm-thick quartz crystals placed 50 microns apart. A high-resolution spectrometer based on a Si(Li) detector coupled to a multichannel analyzer was used for X-ray detection and the spectra were interpreted with the AXIL software. The system was calibrated with standard chemical solutions containing Cr, Fe, Cu, Zn, and Pb, and Y was used as an internal standard to correct eventual geometric errors and high-voltage instabilities of the X-ray generator. The limits of detection were 19, 9, 5, and 4 ng/mL for Cr, Fe, Cu, and Zn, respectively, analyzed through characteristic K alpha X-rays, and 7 ng/mL for Pb, through L alpha X-rays, considering 50 microL samples deposited and dried on a quartz support, to be excited/detected for 1000 s.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Espectrometría por Rayos X
/
Oligoelementos
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Revista:
Biol Trace Elem Res
Año:
1999
Tipo del documento:
Article
País de afiliación:
Brasil