PEAK PURITY CONTROL IN LIQUID-CHROMATOGRAPHY WITH PHOTODIODE-ARRAY DETECTION BY A FIXED SIZE MOVING WINDOW EVOLVING FACTOR-ANALYSIS

A new method for peak purity control of liquid chromatography with photodiode array detection data is proposed, based on evolving factor analysis. In contrast to the original technique, which works on an increasing number of spectra, the new method performs factor analysis on a moving window with a fixed number of spectra. In simulation experiments, the new method proved to be better at detecting small amounts (less than 1%) of a spectrally similar impurity under a main peak than the original evolving factor analysis method. Since latent factors are used, no assumptions are made about peak shape or spectral similarity.