EM start up issues ICP-MS 7800

I've consistently had the issue of the EM start up task not running to completion due to: " EM setting failed because of low signal. Check sensitivity with Performance report. " 

All the tubing has been replaced, fresh standards have been made, the torch, spray chamber, nebulizer have been soaked in 5% nitric acid. The cones have been deep cleaned with nitric acid and citranox soln (all according to the documentation found online through Agilent). 

Current start up procedure is as follows: turn on plasma, signal monitor w/ no gas until the ratios drop below 5% (only the doubly charged ratio starts high and drops), add start up tasks to queue (torch axis, EM, plasma correction, standard lenses tune, resolution/Axis, performance report), signal monitor w/ He gas watching the doubly charged again, add batch to queue. 

 will attach the most recent performance report and batch report. 

The ICP-MS will be professionally serviced by Agilent on Jan 18th 2023. The last service, done last dec, the previous analyst documented that the octupole was serviced/cleaned. Just wondering if this could possibly be an annual issue. 

other notes are the RSD are higher too and the reflected power, while running the batch ONLY not during start up, is above 20W at about 23-26.

Any advice or tips would be much appreciated, thank you. 

-Adrian 

  • Hi,

    there is quite a big drop in sensitivity in August. that's interesting. Are the MassHunter settings for the "Configure Ignition Sequence" "Standard Tune" and are all the Startup tasks, beside the P/A factor and EM run succesfully? please run then a auto rf match if a normal sample is aspirating. You can run it by clicking on the plasma icon in the Hardware ribbon and select "Auto RF Matching". this solves the high reflecting power.

    Please try the EM tuning then with a set of new cones, not cleaned. And a new graphite gasket behind the sample cone. Do this after a successful performance of the lens tuning in the startup task.

    If that doesn't help then maybe the IF/BK pressure is too high for optimal performance. please check if the IF/BK pressure in the PerformanceReport is a bit higher as before.

    You can easy check this by selecting the IF/BK pressure in the "Meter" in the "Select Data Displayed in History View".

    if you see a 30 Pa or more higher pressure then maybe the foreline pump isn't functions as it should be. 

    please contact Agilent if the foreline pressure is far more higher then before and share the PerformanceReport.xml with them to prove this (\agilent\ICPMH\1\PerformanceReport)  

    cheers,

    Edgar

  • Hello and thank you detailed steps Edgar, 

    I did forget to mention that after the deep cleaning a new graphite was installed and every time I remove the torch whenever I reinstall I run an auto RF matching afterwards just to be safe. I did run it again today as you instructed and attempted to EM start again. EM still did not run to completion. P/A factor is not used for our needs in the lab(not in our SOP), we only use Pulse detection. 

    sadly no extra cones on site to use to test. 

    the IF/BK pressure today is 2.52E+2 Pa. Going back to July this seems to be the usual reading we've been getting. Does this require reaching out to service our foreline pump? 

    thank you,

    Adrian 

  • I would get your hands on some new cones to test first. Always rule out the front-end components by testing with new since clean doesn't always mean good. That IF/BK pressure is normal, I consider anything less than 300 Pa on a 7800 to be good. If it's historically been that pressure, it's likely not the issue.

Was this helpful?