Using dual-channel data processing for separation of overlapped chromatographic signals

This article addresses the problem of separating overlapped chromatographic signals using a dual-detector chromatograph. Traditional chromatographic signal processing technology typically employs a single-detector chromatograph. The proposed approach utilizes multi-channel data processing, where the separation process in the column is recorded by multiple detectors. In the case of a dual-detector chromatographic information-measuring system (IMS), two non-selective detectors with different sensitivities to the sample components are used. This enables a fundamentally new approach to separating overlapped signals. The separation is based on special mathematical transformations of the overlapped signals from the two chromatographic detectors. The ratio of the first detector's signal to the second detector's signal (and vice versa) is calculated, yielding certain coefficients as functions of time. Using these coefficients, relationships are derived to reconstruct the unresolved components of the signals from the first and second detectors, respectively. The proposed separation method can be applied to both symmetric and asymmetric peaks. Examples of peak reconstruction for various resolution values are presented. To obtain smoothed values of the reconstructed peaks during signal separation in noisy conditions, a standard MATLAB procedure of cyclic averaging over a short interval is employed. To preserve the width of the reconstructed peaks in the separation algorithm under noisy conditions, it is proposed to approximate the ratio of the detector signals using a hyperbolic tangent function. Examples demonstrating the effectiveness of smoothing are provided.