Chromatography without spectral detectors such as diode array, mass-spectral or fast scanning is unthinkable today. Recorded with such detectors, a chromatogram consists of spectra (set of measurements for different wavelengths, masses, etc.) evolved over time. Another way to get a multi-channel chromatogram is to measure several responses from different detectors, connected consecutively or in parallel, such as UV+RI+radioactivity detector in LC or TCD+FID+ECD+FID in GC. In this case, the spectrum is a set of responses of all detectors in use at one time.

Factor analysis considers a region of multi-channel chromatogram by comparing all the spectra in the region using linear algebra.

Factor analysis of the chromatographic peak shows whether the substance being eluted is homogeneous or not. If the peak originates from one component, spectra within the whole peak will be similar. If spectra within the peak are significantly different, the peak consists of two or more overlapped peaks.

The main goal of factor analysis is computational separation of the peaks that are not separated by chromatography.

Chrom&Spec uses self-modeling factor analysis which enables pure component detection. This approach is based on the concept of “best local purity” for spectra of the peak. Using the spectra obtained, the full elution profile of every component can be reconstructed.

In many cases factor analysis is a very precise method, allowing not only detection of an extra component, but also providing the correct quantification of the extra component.