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Topic: simulation of mixtures/isotope labeling

hi, I wonder if there is a simple solution in mmass to the simulation of mixtures. Basically I want to simulate an oxygen isotopic labeling experiment for a given number of exchangeable positions using an experimentally determined 16O/(16O+18O) ratio. I have tried the fitting tool, but this does not really do what I need.

Right now my solution is to simulate all possible the compounds separately and multiply the single spectra by their statistically calculated fractional amount followed by summation of all spectra.

However this is a bit tedious, if you you need to vary the fractional amounts. Is there a simple solution I might have overlooked?

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Re: simulation of mixtures/isotope labeling

Hi I would suggest the fitting tool but since you have already tried that and it did not helped, than I have no other idea.

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Re: simulation of mixtures/isotope labeling

Then this might turn into a feature request/suggestion :). A feature I very much like in Xcalibur (although in general I really do like mMass a lot better) is that it is possible to calculate mixtures in the following  way:
H2O2*0.25 + H2O[18]O * 0.50 + H2[18]O2 * 0.25

maybe this would be great as an addition to the math section of mMass or to the mass calculation itself.