Algorithms for time-dependent chromatographic peak areas - II. Resolution of overlapped chromatograms for two- and three-component samples

This paper introduces a new approach for the quantitative resolution of ove rlapped chromatographic peaks. In this new approach, sigmoid models are use d to resolve area versus time data for overlapped chromatographic responses . The capability of the approach to resolve peak areas was evaluated for ar tificially overlapped chromatographic peaks and real unresolved multicompon ent samples with degrees of resolution from 1.53 to 0.39 and peak-height ra tios (leading/trailing) from 0.15 to 5.94. Results demonstrated the feasibi lity of using area data rather than peak data to resolve components that ar e not fully resolved in chromatographic processes. The degree of peak overl ap has less impact on the sigmoid-based options than on a conventional peak -shaped option using the exponentially modified Gaussian (EMG) model. For s mall degrees of overlap (R-s > 0.7), performance characteristics for the si gmoid-based models are similar to those for the EMG model. However, for lar ger degrees of overlap (R-s < 0.7), performance characteristics for the sig moid-based models are superior to those for the EMG model. For example, rel ative errors for sigmoid-based resolution results for overlapped responses for 2- and 3-nitrotoluene (R-s = 0.6) were mostly within about 2.5% whereas errors for EMG resolution were mostly in the range of 20-30%. (C) 2000 Els evier Science B.V. All rights reserved.