[en] A method for quantitative n.m.r. analysis is proposed based on the cross-correlation of a reference spectrum with a series of sample spectra. The calculated cross-correlation functions are proportional to sample concentration. The method can be applied at low sample concentrations of the order of 0.1%, under which conditions the 60-MHz n.m.r. signals become buried in base-line noise and cannot be integrated by the more usual methods. The proposed method greatly extends the lower limit of sensitivity for quantitative n.m.r. analyses and is of general applicability