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TSQ Vantage - background in negative mode.
Posted: Thu Nov 23, 2017 9:25 am
by Oxabolone
Hello all. In last time in negative mode appeared a huge background peak with 169 m/z. What can it be and how to remove it ? I've tried to clean ESi box, wash tubes but without effect.
Thanks!
Re: TSQ Vantage - background in negative mode.
Posted: Thu Nov 23, 2017 2:59 pm
by Rndirk
Did you isolate it to the MS only?
Re: TSQ Vantage - background in negative mode.
Posted: Fri Nov 24, 2017 9:49 am
by Oxabolone
Did you isolate it to the MS only?
In case calibration with polythyrosine (direct infusion in mass) or direct conection LC without column - the same strong 169 m/z.
Re: TSQ Vantage - background in negative mode.
Posted: Fri Nov 24, 2017 11:52 am
by Rndirk
What if you just turn on the MS without infusion or column flow?
If it's still there and it's bothering your analysis, i'd advice to take cleaning 1 step further and clean the part behind the transfer tube: the first lens system/ion funnel.
If you don't have experience doing that it's best to ask Thermo.
Re: TSQ Vantage - background in negative mode.
Posted: Fri Nov 24, 2017 12:32 pm
by Oxabolone
What if you just turn on the MS without infusion or column flow?
If it's still there and it's bothering your analysis...
I tried to do such way,but peak is still here (.
So i have to clean capillary and ion optics(we can do it without Thermo service).
Thank you so much!
Re: TSQ Vantage - background in negative mode.
Posted: Mon Nov 27, 2017 9:28 am
by Oxabolone
Sorry for confusion. Ii checked out system one more time - contamination with 169 m/z goes from channel of pump with organic phase. Very strange thing - i got excellent tune with polythyrosine in positive and negative modes, but instrumental method in MRM doesn't work properly. MRM in negative - no signal. in positive -everything good.