A Matrix-Matched Reference Material for Validating Petroleum Re-Os Measurements

作者：Liu Junjie^*; Selby David

来源：Geostandards and Geoanalytical Research, 2018, 42(1): 97-113.

DOI：10.1111/ggr.12193

• petroleum
• Re-Os measurements
• reference material
• N-TIMS
• RM 8505 crude oil
• homogenised asphaltene powder

This study presents two matrix-matched reference materials developed for petroleum Re-Os measurements. We present the Re and Os mass fractions and Re-187/Os-188 and Os-187/Os-188 values (ratio of the number of atoms of the isotopes) for repeatedly measured aliquots (ca. 120-150mg test portions) of the NIST Research Material 8505 (RM 8505) crude oil, and its asphaltene and maltene fractions, and similar to 90g of homogeneous asphaltene powder isolated from this oil. Measurements were performed using the Carius tube-isotope dilution negative-thermal ionisation mass spectrometry methodology. The RM 8505 crude oil contains 1.98 +/- 0.07 ng g(-1) Re and 25.0 +/- 1.1 pg g(-1) Os, with Re-Os isotope amount ratios of 452 +/- 6 for Re-187/Os-188 and 1.51 +/- 0.01 for Os-187/Os-188 (n = 20, 95% conf.). The homogeneous asphaltene sample contains 16.52 +/- 0.10 ng g(-1) Re and 166.0 +/- 0.9 pg g(-1) total Os, and possesses isotope amount ratios of 574 +/- 3 for Re-187/Os-188 and 1.64 +/- 0.01 for Os-187/Os-188 (n = 24, 95% conf.). The intermediate precision of these data makes the RM 8505 whole oil and the (similar to 90 g) homogenised asphaltene appropriate petroleum matrix-matched reference materials for Re-Os measurements. The asphaltene fraction of the oil is the main carrier of Re and Os of the RM 8505 whole oil, and caution is suggested in using asphaltene and maltene fractions of a single oil for Re-Os geochronology.

• 出版日期2018-3