High ratio of mass 70 to mass 69 and high mass 69 precursor

When I run tune evaluation it reports that mass 70 to mass 69 is high, as well as the mass 69 precursor, should I be overly concerned?  If so how do I fix it?  I'm also questioning the background/stability and I'm wondering if there is a leak or leaks.  I attached the auto tune, tune evaluation and air/water check reports.  When I compare recent injections of the a standard to the same injections of this standard from around 6-7 months ago the TIC baseline noise seems worse and the quality of peaks is not as good; the peaks are much smaller and not as well defined.  Is this possibly due to bad background because of a leak or something else?

  • Turn the column flow down to 1.2 milliliters per minute, let it stabilize, and then run a tune and a tune evaluation.  The HES source does not work the same at 2.0 ml/.min and troubleshooting at that flow rate is invalid.  The acceptable helium flow rate when using the HES is 0.75 to 1.4 ml/min of helium - -things get interesting lower or higher than that.  It will certainly work, but the tuning is different and some parameters and values will be outside of the typical historical ranges.   I bet that what looks like an air leak at 8% will be much lower....and the other issues may disappear.

    Please share those reports!

  • Thanks! That worked.  I attached the most recent tune report, tune eval., and air/water check.

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