Lithium tuning report shows contamination of Li6 in No Gas Mode

Hello
I have problems with Lithium Tuning Report, see picture. I've already changed hoses and the nebulizer. What else can I do? I can't explain anymore why my peak in no gas mode looks so weird with the lithium peak. I know that could indicate contamination. But where else do I have to look?

Thanks                  

  • The peak to the left in the Lithium window is Li6.  This is from internal standard solution.  Li6 abundance is typically very low and should not be larger than the Li7 peak.  When you run start the plasma, is the internal standard (ISTD) line in a nitric acid rinse or in the ISTD solution? It is recommended you give it the full warmup time in nitric rinse to wash out the ISTD solution for the Performance Report and your batch tune.  Then put the line back in the ISTD solution and fast pump it so it reaches the nebulizer before adding the Batch to Queue.

    Counts are low as @lisandrom91 stated.  Is the picture sent from a Batch running an HMI setting or General Purpose Plasma condition set?  If not in Low-Matrix plasma condition set, you may want to run 10ppb tuning solution.  If you are in Low-Matrix set how do the counts look in the Performance report?  Li7>3000 counts, Y89 >10000 counts, Tl205>6000 counts?  If performance report is also low, check sample introduction.  Nebulizer is the most common cause, then pump tubing, next torch/shield/bonnet.  Check cones and lenses as well.  

  • To find where the Li6 is coming from, directly aspirate 1ppb tuning solution from the nebulizer line.  If that peak goes away it is located in a component before that line (mixing block or internal standard line).  The ISTD line is much smaller diameter than the sample line so it takes longer to rinse out, When you fire up the instrument, make sure the ISTD line is in a Nitric Acid only solution.  HCl will cause the ++ ratio to fail in the performance report.  This way there should be enough time for the Li6 from the internal standard to wash out during warmup.

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