Missing qTOF Reference Ions

Hello,

 

I am not seeing all of the reference ions (negative or positive) while my qTOF instrument is in idle or acquisition.  Spectrum and Work List icons remain yellow whereas Vial icon remains red. A fresh reference solution was prepared, flow and function of nebulizer confirmed. Some additional details as follows:

 

  • In negative mode, seeing only 112 and 1033 m/z.  Not seeing 119, 301, 966, 980, 1633 m/z.  Similar scenario in positive mode; seeing only 121 and 922 m/z.
  • Played with MP flow rate, reference nebulizer pressure and other parameters to no avail.
  • I have a dual ESI source.  Set up for small molecule analysis; 1700 m/z, 2 GHz.
  • Instrument recently passed calibration and tune for TOF and Quad.
  • Acquisition software recently upgraded to Version 10.  Methinks this is the culprit..?

 

Best regards,

Mark

Parents
  • No other reference ions beyond the TFA, Purine and HP-0921 that were used to prep the ref mix.  I see TFA (112 m/z) and HP-0921+TFA (1034 m/z) but not purine (119 m/z).  Also, I do have HOAc and HCOOH in my MP, so I should see 980 and 966 m/z.  

Reply
  • No other reference ions beyond the TFA, Purine and HP-0921 that were used to prep the ref mix.  I see TFA (112 m/z) and HP-0921+TFA (1034 m/z) but not purine (119 m/z).  Also, I do have HOAc and HCOOH in my MP, so I should see 980 and 966 m/z.  

Children
  • Hi Mark,

     

    Are you running in Pos or Neg mode or both?

     

    If you are running in Pos mode you only need to see the ions at 922 for HP-0921 and 121 (Purine).        As long as these reference ions bracket your ions of interest within your analytical run,   the reference ion correction will work as expected.    Please also keep an eye on abundances of each of these ions across your gradient and you may need to fine tune these abundances.  The stock recipe for making up the reference ion solutions typically works well.

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