MS recommendation for small molecules

[FastLC]

I am in the process of evaluating mass spec's to replace the current ESI-TOF in my lab. I would like to move more into the areas of structure determination (tandem MS) of small molecules, and realize I will be giving up resolution and mass accuracy from the ESI-TOF.

The 3 mass specs under consideration are the Agilent XCT-Ultra; the Applied 3200 Q-trap and the Thermo LXQ.

Any recomendations, red-flags, etc to help me in my decision.

Thanks....

[Kostas Petritis]

Do you have to give your ESI-TOF away? If you have space in your lab it would maybe a good idea to perform your separation twice and you could probably still have high mass accuracy and MS/MS information. Maybe you can try to be more fancy and split your flow after a column and introduce it to the two mass spectrometers...

Otherwise, I would probably invest on a Q-ToF, probably the upcoming Agilent one. I think that upcoming developments in accurate mass accuracy based methods for unknown identification will make it worthwhile to have high resolution/high mass accuracy instruments in your lab...

[FastLC]

Dear Dr. Petritis,

Thank you for your reply. I will indeed look into the option of keeping the ESI-TOF and adding additional capabilities of one of the other 3 instruments.
Do you have any experience with any of the other mass specs, in regards to small molecule analysis? Have you ever seen a need to do MS>3 on a small molecule (<1000 amu)?

Your opinions are highly valued.

Thanks

[Kostas Petritis]

We are doing most of our metabolomic work on an Agilent ESI-TOF and a Thermo Orbi-trap. Most of the work for the ESI-TOF was for differential expression work. For structural determination, you will rarely have the opportunity to do MS>3 due to sensitivity considerations (not enough ions if you go beyond MS^3)...

In the lab we have an Agilent XCT-Ultra that we are indending to upgrade with an electron transfer dissociation interface but using mostly for proteomics. The Agilent ion trap does the job and is quite sensitive... We have 6 LTQ's but none LXQ and no Applied Q-traps so I can not really comment for the last two ones.