Method for preparing petroleum based samples for analysis of elemental and isotopic species

摘要

A method of separating petroleum samples containing a hydrocarbon-soluble elemental species of interest to facilitate analysis of an elemental and/or isotopic signature. A petroleum sample is mixed with a demulsifier and separated, for example by centrifuging, into one or more intermediate organic fractions. The intermediate organic fraction(s) are mixed with a solvent such as water and a second demulsifier, then separated into one or more prepared organic fractions and one or more solvent-based fractions. Some or all of the resulting fractions are then stored for possible further processing. Optionally, the petroleum sample may be spiked with one or more of an organic standard and an inorganic standard, and the solvent may likewise be spiked with an inorganic internal standard, to facilitate later analysis.

主权项

1. A method of preparing a petroleum sample having an inorganic contaminant species for use with one or more of elemental and isotopic signature analysis, comprising:
(a) adding a first demulsifier to the petroleum sample, said first demulsifier having a known concentration of a specified hydrocarbon-soluble elemental species referred to as a species of interest; (b) separating the petroleum sample into one or more intermediate organic fractions and one or more inorganic fractions; (c) mixing the one or more intermediate organic fractions with (i) a solvent in which the inorganic contaminant species is soluble and the solvent has a known concentration of the species of interest, and (ii) a second demulsifier having a known concentration of the species of interest; (d) separating the one or more intermediate organic fractions into one or more prepared organic fractions and one or more solvent-based fractions; and (e) determining at least one of an elemental signature and an isotopic signature from the one or more prepared organic fractions.