Table I Effect of mass resolution on the confidence interval of mass accuracy (mass tolerance). Example of pesticide Pirimicarb (C11H18N4O2; [M+H]+ = 239.15025) illustrating how the mass tolerance can limit the number of elemental composition suggestions, and hence greatly assist a compound identification. Resolution 15,000 and 80,000 (FWHM) and CHNO elements considered in this example
ResolutionMass tolerance (mmu)Number of elemental composition suggestions
15,000+/− 914
80,000+/− 1.71