Agilent 5975 MSD tuning evaluation issue

I did auto tuning for Agilent 5975 MSD and found the following message" ratio of mass 219 to 69 should be >40% and is 33.1%, low" in tune evaluation report. Everything else is ok. The instrument runs ok. What does this mean and is there anything we need to do to address that? 


thank you. Tune evaluation reports are attached. 

  • Good afternoon,


    it appears the source needs to be cleaned. You may still acquire good results, but this looks to be a dirty source at the moment. 

  • Hi smathers 

    Hope you are well!!!  

    actually even after cleaning of source and replacing of both the filaments i am still facing the same issue again again. 
    can you please suggest something.

  • change rough pump oil and mist filter( if connected ) also..

  • Change the insulators in the source.  One of my customers puts high amounts of water into their MS and have the same tuning problem.  Cleaning the source and replacing insulators and filaments helps resolve it.

  • Hi, what type of analysis are you running? For example is this pesticide analysis, residual solvents, etc? I'm also curious what type of sample matrix you are using. 

    A drop in transmission of 219/69 and 502/69 is typically related to the source. It could be related to the quadrupole, but a source related issue is actually more common (if the electronics controlling the quad were to fail, you'd just lose transmission of ions completely--not lose transmission of high the higher mass ions.) I agree with the recommendations to clean the source and to replace the ceramic and vespel insulators (ceramic insulators around the repeller, vespel lens stack insulator that holds all the lenses inside the body.) These insulators can become contaminated and can lead to issues with the source. New filaments at the same time is a good idea as well.

    If this source is quite old, it may actually be a better idea to simply buy a new source. That way you would be starting out with all new components. If this doesn't solve it, then at least you now have a spare source so that when it is time to clean the ion source you can vent, exchange sources, and immediately pump the system back down. Clean the dirty source and store it in a dessicator (or at least a dry, clean area) until the next maintenance is needed.

    If replacing the filaments/insulators or entirely replacing the source does not solve it, then it may be possible that matrix has contaminated the magnet and source radiator that the source is installed into. I have see contamination of this area impact transmission of ions through the quad, but it is typically with applications that (a) contain high boiling matrix, (b) have been running the analysis for thousands and thousands of injections over years of work. Depending what your application is (if you fit these criteria) it may make sense to have an Agilent FSE come and clean these parts of the instrument and do a thorough inspection of the rest of the analyzer (I would not recommend someone untrained try to clean or repair these other parts by themselves.)

Was this helpful?