Dear Isotopers,

    Hope all is well.
    Here is some dummy questions: I have a typical Costech EA-CF-IRMS system for sulfur isotope analysis for all forms of sulfur bearing materials.
There is no O-18 correction applied to Mass 66,and no constraints on d18O of tank O2,  W2O3 and V2O5 either.
Some research indicate the need for O-18 correction/reset. Is it a routine practice for O-18 reset using
    I thought, and per communications with Thermo tech support, SOO18 takes only very small portion of total SO2,
the high T and multiple oxygen sources may also somewhat homogenize SO2 gas with respect to oxygen. Therefore, unless some materials are highly enriched or
depleted for O18, the contribution from SOO18 should be minimum and within the error range of the analysis , i.e. 0.3 to 0.5 per mil.
    Any suggestions would be of great help.

Thanks in advance,