Determination of chromatographic peak parameters by non-linear curve fitting using statistical moments

There are many methods (manual, computer), which make possible the detailed analysis of chromatographic peak shape. Curve fitting seems to be one of the successful applications of the evaluation of chromatographic signals. In this case, a mathematical function is fitted to the digitized measuring points. Chromatographic elution curves are generally asymmetric, so it is necessary to find the best mathematical function, which corresponds perfectly to the signal form, and then to determine the parameters of the found equation. In this work a modified mathematical function is presented and used for curve fitting, in which the starting parameters are calculated from the statistical moments (retention time, variance, skewness, excess) of the peak shape. The fitting process gives a more accurate and rapid determination of peak shape characteristics, noise filtering and correction of baseline. The suggested modified Gaussian function, the simulated chromatographic peak shapes, the application of the function to the description of real signals and the parameters obtained by the fitting process will be demonstrated.