Improvement of the signal-to-noise ratio of chromatographic peaks by Fourier transform

Abstract A method is described for digital smoothing of chromatographic signals by using Fourier transform and is compared with some earlier methods. A new procedure is reported for determining the correct value of the cutoff frequency; a smoothing window is described which distorts the frequency function only slightly at low frequencies but smooths the data to zero at the cutoff frequency without sharp discontinuity. These operations produce effective noise filtering with little deformation of peaks. The relative improvement of the signal-to-noise ratio is significant. Exact evaluation of peak parameters is made possible by these results.