TY - JOUR
T1 - Efficient N-TIMS rhenium isotope measurements on outgassed tantalum filaments
T2 - Very low filament blanks determined by a "standard addition" approach
AU - Frei, Robert
AU - Nägler, Thomas F.
AU - Meisel, Thomas
PY - 1996/1/1
Y1 - 1996/1/1
N2 - We have successfully tested two sets of Ta filaments for their suitability to measure Re isotopes by negative thermal ionization mass spectrometry. No significant Re contribution from the filament material itself could be detected. Therefore Ta filaments are a viable, low cost alternative to high purity Pt filaments which are commonly used for Re-Os isotope analyses. A technique whereby Re is directly loaded with H2SO4 into Ba(NO3)2 and precipitated together with BaSO4 on the filament has resulted in stable and constant ion beams. Furthermore, slight oxidation of the Ta filament surface significantly facilitates point loading in the center of the filament. The BaSO4 loading technique has proved to be less sensitive towards time-consuming pre-analytical heating procedures than Ba(NO3)2 on Pt filaments. Furthermore, Re isotopic ratios remained constant over a wider range of measuring temperatures, in contrast to what we observed during Re analyses from Pt filaments loaded with Ba(NO3)2 or BaSO4.
AB - We have successfully tested two sets of Ta filaments for their suitability to measure Re isotopes by negative thermal ionization mass spectrometry. No significant Re contribution from the filament material itself could be detected. Therefore Ta filaments are a viable, low cost alternative to high purity Pt filaments which are commonly used for Re-Os isotope analyses. A technique whereby Re is directly loaded with H2SO4 into Ba(NO3)2 and precipitated together with BaSO4 on the filament has resulted in stable and constant ion beams. Furthermore, slight oxidation of the Ta filament surface significantly facilitates point loading in the center of the filament. The BaSO4 loading technique has proved to be less sensitive towards time-consuming pre-analytical heating procedures than Ba(NO3)2 on Pt filaments. Furthermore, Re isotopic ratios remained constant over a wider range of measuring temperatures, in contrast to what we observed during Re analyses from Pt filaments loaded with Ba(NO3)2 or BaSO4.
KW - Isotope measurements
KW - Negative ions
KW - Thermal ionization mass spectrometry
UR - http://www.scopus.com/inward/record.url?scp=4243626642&partnerID=8YFLogxK
M3 - Journal article
AN - SCOPUS:4243626642
SN - 1387-3806
VL - 153
SP - L7
JO - International Journal of Mass Spectrometry
JF - International Journal of Mass Spectrometry
IS - 2-3
ER -