41Ca ultratrace determination with isotopic selectivity > 10(12) by diode-laser-based RIMS.
41Ca ultratrace determination by diode-laser-based resonance ionization mass spectrometry with extremely high isotopic selectivity is presented. Application to environmental dosimetry of nuclear reactor components, to cosmochemical investigations of production cross sections, and biomedical isotope-tracer studies of human calcium kinetics are discussed. Future investigations are possible use in 41Ca-radiodating. Depending on the application, 41Ca isotopic abundances in the range of 10(-9) to 10(-15) relative to the dominant stable isotope 40Ca must be determined. Either double- or triple-resonance optical excitation with narrow-band extended cavity diode lasers and subsequent non-resonant photoionization of calcium in a collimated atomic beam were used. The resulting photoions are detected with a quadrupole mass spectrometer optimized for background reduction and neighboring mass suppression. Applying the full triple-resonance scheme provides a selectivity of approximately 5 x 10(12) in the suppression of neighboring isotopes and > 10(8) for isobars, together with an overall detection efficiency of approximately 5 x 10(-5). Measurements on a variety of sample types are discussed; the accuracy and reproducibility of the resulting 41Ca/40Ca isotope ratios was better than 5%.
Müller
P
P
Institut für Physik, Johannes Gutenberg-Universität, Mainz, Germany.
Bushaw
B A
BA
Blaum
K
K
Diel
S
S
Geppert
C
C
Nähler
A
A
Trautmann
N
N
Nörtershäuser
W
W
Wendt
K
K
D002132:Calcium Radioisotopes / Q000652:urine*; D006801:Humans; D013058:Mass Spectrometry
D002132:Calcium Radioisotopes