NCI GCMS methane pre tune and PCI tune failing but NCI tune passing

Load a previous tune like one that worked some months ago.

 Or, go back to an older data file that has PCICH4.U underneath the subdirectories and load that one.

The CI Wizard screen: "Enter Reagent Ion Masses for Flow Adjustment"  must be 17, 29, 41. 

The PCI Tune Ions must be 41, 267, 599.

If you load PCICH4.U and select the More... button

The defaults are these:

Good job trying EI, the EI filament in CI, and NCI to prove that the rest of the MS is working!

Hi Paulo, I have tried with previous good tune file, and also tried another file putting default values, but issue is same. Improper mass axis for calibration.

In EI, the Mass Gain and Offset are 0, -23.  In NCI, the Mass Gain and Offset are -4, -20 << almost the same as EI.

In PCI when it fails, the Mass Gain and Offset are 2047, -481 -- so the mass assignment is very wrong for flow adjust with Methane as the reagent gas.  The PCI tune algorithm is trying to adjust the mass gain and offset for the largest peak in the window and drive it to the setpoint for the CI gas selected. Please make sure that your CI gas is configured to be Methane. If it's configured for Ammonia or Isobutane the algorithm will be trying to drive to those masses.

Or, manually change the Mass Gain to 0 and the Offset to -20, and manually run the methane pre-tune to see if that finishes rather than running Autotune.

In EI, the Mass Gain and Offset are 0, -23.  In NCI, the Mass Gain and Offset are -4, -20 << almost the same as EI.

In PCI when it fails, the Mass Gain and Offset are 2047, -481 -- so the mass assignment is very wrong for flow adjust with Methane as the reagent gas.  The PCI tune algorithm is trying to adjust the mass gain and offset for the largest peak in the window and drive it to the setpoint for the CI gas selected. Please make sure that your CI gas is configured to be Methane. If it's configured for Ammonia or Isobutane the algorithm will be trying to drive to those masses.

Or, manually change the Mass Gain to 0 and the Offset to -20, and manually run the methane pre-tune to see if that finishes rather than running Autotune.

hi 

I have tried putting mass offset and gain value in manual tune and manually did methane pre tune. But its not adjusting 17 and 29, but only 41.

I have checked manual profiling for 41, 267 and 599, its only getting 41 abundance around 600k, but other masses abundance are around 40-50.

Sorry, running out of things to try without seeing it.  Please contact Agilent for support: Contact Us | Agilent