Algorithms for time-dependent chromatographic peak areas - 1. Algorithms evaluated for fully resolved peaks

This paper describes a preliminary study of an alternative method to fit ch romatographic data. Peak-shaped responses are integrated to obtain unidirec tional data for area versus time and an empirical model is used to fit the data. Results are reported for two similar models, each of which characteri zes the total sigmoid function for each component in terms of the leading a nd trailing segments of two separate sigmoids. The use of leading and trail ing segments of two sigmoids makes it possible to fit area chromatograms wi th large degrees of asymmetry. Performance of the models was evaluated by f itting them to data for single-component experimental and simulated data wi th degrees of asymmetry at 10% of peak height between 0.37 (fronting) and 7 .33 (tailing). Results obtained using the area-based models are compared wi th results obtained by fitting a commercially available model for an expone ntially modified Gaussian (EMG) to the peak data from which the area data w ere obtained. Areas computed using the two area-based models vary linearly with barbiturate concentrations over 100- to 200-fold concentration ranges and are more rugged to changes in peak shapes and asymmetry than the EMG mo del. Both area-based models give substantially smaller errors in peak area and smaller root-mean-squared fitting errors than the EMG model for peaks w ith moderate to high degrees of asymmetry. (C) 2000 Elsevier Science B.V. A ll rights reserved.