Mass of TFA

[Chandresh K. Soni]

We Have the Mass of Waters Inc. with masslynx Software.
My problem is when we injecting the samples or water or methanol or Acetonitrile we got the strong signals of M/z 69 and 113.
in complete procedure we are not using any kind of buffer and TFA.
but my R&D personnels saying that this is the mass of Trifluoro Acetic Acid.
is it possible

[Don_Hilton]

Without a bit more detail, it is hard to rule anything out. There is no indication of the history of the instrument or the conditions in which it is being used.

[Chandresh K. Soni]

In our Previous Experiments we used TFA as Buffer( 0.1%), but after up to three days we clean the Mass lines with water , MeOH and Acetonitrile.
After that we injected the saqmples and we got the mass in water , MeOh , acetonitrile and also in Samples where due to presence of these mass the interpretation is not clear whether these are from samples or from systems.

[lmh]

this probably won't help much now, but it's generally a good idea not to use TFA in LC-MS if you can possibly avoid it. In most instruments, for electrospray, it badly reduces ionisation efficiency and leads to very poor results. Nearly always a simple substitution of formic acid for TFA will improve a method from the mass spec point of view, without totally messing up the chromatography!

[Alp]

Once you use TFA in a system it is going to show up regardless of what your mobile phase is. Even a cleaning of the system may not get rid of it all.

Alp

[Kostas Petritis]

Do you see TFA if you only infuse? Do you use an on-line degasser? The later generally has been shown to adsorb perfluorocarboxylic acids and release them slowly. Other parts can be cleaned much easier.