0000000000415402
AUTHOR
P. Mueller
Counting individual 41Ca atoms with a magneto-optical trap
Atom Trap Trace Analysis (ATTA), a novel method based upon laser trapping and cooling, is used to count individual atoms of 41Ca present in biomedical samples with isotopic abundance levels between 10^-8 and 10^-10. ATTA is calibrated against Resonance Ionization Mass Spectrometry, demonstrating a good agreement between the two methods. The present ATTA system has a counting efficiency of 2x10^-7. Within one hour of observation time, its 3-sigma detection limit on the isotopic abundance of 41Ca reaches 4.5x10^-10.
Selective ultra trace isotope determination in environmental and biomedical studies by high-resolution resonance ionization mass spectrometry
The precise determination of relative abundances of ultra trace isotopes in the range below 10 -9 is of importance for a wide spectrum of applications in fields like environmental protection, cosmo-chemistry, bio-medical tracer studies or geological and geo-chronological investigations. The necessary high isotopic selectivity, rather complete isobaric suppression and good overall efficiency for these investigations is provided by high-resolution resonance ionization mass spectrometry. Multi-step continuous wave laser excitation and ionization using diode lasers at a compact quadrupole mass spectrometer has been optimized to become a powerful and reliable experimental method, which is just b…