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- Posts: 1
- Joined: Tue Jul 26, 2011 2:47 pm
Rather than compare the signal to noise, I have been asked to make a meaningful comparison between the ratio of two baseline corrected peak areas and the peak-to-peak noise. Can this be done?
You need to talk to your advisor/professor and get some background on what question is being asked (or, what hypothesis is being tested!). Here's a *possible* interpretation:
In principle, if you take the ratio of two quantities that are subject to errors (expressed as relative standard deviation):
- if the errors are perfectly correlated, they will cancel and the ratio will be error-free (in practice, nothing is perfectly correlated, but the relative standard deviation of the ratio will be lower than the relative standard deviations of the individual quantities).
- if the errors are uncorrelated, the relative standard deviation of the ratio will be the square root of the sum of the squares of the individual relative standard deviations (again, in practice it's not that neat, but the relative standard deviation of the ratio is higher than the relative standard deviations of the individual quantities).
In chromatography, most people assume that the dominant source of uncorrelated errors is baseline noise, so looking at the relative error in the area ratio as a function of baseline noise may provide some insight into the relative contribution of the baseline correction algorithm.
