Quantitative Applications:

NMR spectrum has a unique feature of direct proportionality between peak area and the number of nuclei responsible for that peak. Unlike other spectroscopic techniques where a calibration plot is prepared by using a pure compound of varying concentrations, no pure sample is needed for calibration in NMR. Therefore, if an identifiable peak for one of the constituents of a sample does not overlap with the other constituent peaks, the area of this peak could be used to form the concentration of the species directly provided that signal area per proton is known. The signal area per proton, instead, can be computed through using a known concentration of an internal standard.  It might be emphasised in which the peak of the internal standard should not overlap with any of the sample peaks. In that regard organic silicon compounds are unique for calibration reasons because of high up field location of their proton peaks.