Hello Sun,

the answer to your question depends on what you want to do? If high throughput is a focus, then FTICR-MS is out of the question due to the low scan rate. Where FTICR-MS is used is e.g. MALDI-Imaging. Here it delivers great results due to high resolution and mass accuracy. It's also a question of money: FTICR-MS devices can quickly cost up to 1 million Euros. Orbitraps may be a much cheaper alternative with only insignificantly worse performance data. If it's going to be even cheaper, then maybe think about Q-TOF's. As I said: Everything a question of money. What you shouldn't lose sight of are the operating costs. At FTICR's the magnet is cooled with helium and that's not cheap either.

Regards

Markus

Hi Sun,

For routinely metabolomics, in general, I do not see a clear advantage of using FT-ESI-ICR-MS compared to other high-resolution mass spectrometers (e.g. Orbitrap).

FTICR can achieve ultra-high resolution (over 2,000,000 in a 21T), however, the scan rate is very low and for this reason it is typically used with direct infusion, so no chromatographic separation is implemented. In this case you would only obtain ultra-high resolution mass values, which is not enough as to provide any identification and this data is commonly used for formula assignment. In order to cope with chromatography, typically liquid chromatography, you should decrease the resolution of the mass spec being thus not very different from an Orbitrap.

Another factor to consider is the Automatic Gain Control (AGC). AGC is very useful for a more robust relative abundance comparison and it is present in Orbitrap mass spectrometers. However, not FTICR mass spectrometers are equipped with AGC which could provide a bias in the relative abundance of certain coumpounds due the low/high efficiency in the spray (ESI).

For routinely metabolomics (and if you can), my suggestion is to go with a high-resolution mass spectrometer (Orbitrap (there are several models and all of them will function pretty well for your goals)). You can achieve decent resolution (>100,000) at relatively high scan rate which allows you to perform tandem mass spectrometry while coping with chromatographic separations.

Hope it helps a bit!

Good Luck!

Higher resolution instruments are only really necessary for higher mass ions, where there are different combinations of C, H, N, O, S that add up to the same number of nucleons but differ only by their mass defects. There are very few natural organic molecules below 500 Da that have such nearly-isobaric overlaps.

Hi, This is a very interesting and relevant question for the entire research community working in metabolomics. Please also feel free to register (for free to create a login with your Email ID!) and join the International Metabolomics Society’s Forum: http://www.metabolomics-forum.com/index.php?action=forum;?action=forum#c12 to ask more specific questions any software, database, approach and platform (mass spectrometry, NMR) issues where you can get very specific responses from expert users and researchers! Thanks again, Biswa