Application of time-domain differentiation of chromatographic peaks in liquid chromatography

The differentiation of chromatographic bands with respect to time is useful for improving the resolution of overlapping peaks owing to the reduced band widths of derivatives in comparison with the original bands. An IBM XT 286 microcomputer was interfaced to a Perkin-Elmer liquid chromatographic system and software was developped to allow the acquisition and digitization of chromatographic data for subsequent manipulation, storage and graphical representation. Smoothing and differentiation of chromatographic bands with respect to time were done by the Savitzky-Golay method. The method was applied to the determination of a mixture of antioxidants used as additives in nutrition. The overlapping peaks corresponding to propyl gallate and tert-butylhydroquinone were resolved by time-domain differentiation.