The isotope ratio data from my Q-TOF is usually way off. Can Rational Numbers work without isotope data?
No, the search engines require isotope ratio data on the protonated or deprotonated molecule because this data will restrict the elemental compositions that are possible. For an excellent discussion of the impact of isotope data and other important considerations, see The Seven Golden Rules. On some instruments the centroiding parameters needed for optimizing accurate mass are not conducive to getting good isotope ratios; two different sets of parameters are really needed. For example, centroid 80% height with Np = 0.7 may improve mass accuracy, but for optimizing isotope ratios, try centroid 99% area and disable the time correction factor. Most Q-TOFs are capable of giving excellent isotope ratios when the proper parameters are used.
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- The isotope ratio data from my instrument is sometimes way off. Can Rational Numbers Search work without isotope data?
- The isotope ratio data from my Q-TOF is usually way off. Can Rational Numbers work without isotope data?
