So I know the answer to this question varies widely across mass spec techniques, masses, and, of course, budgets, but my question is about the best case scenario for all of these variables (although I'm not really looking at proteins or anything of that size). I realize that the concept of depletion spectroscopy relies heavily on very sensitive mass spectrometers, and I'm curious about the lower limits of signal detection for such methods. Thus, I'm interested in the sensitivity, not resolution ("mass resolving power"), which seems to be a statistic that is difficult to find for most of the systems that I've looked at. Some related follow-up questions are what mass spectrometry methods can and cannot be used with depletion spectroscopy and what methods/manufacturers are the gold standard in the field of mass spec?
Thanks in advance for your answers.