A Chromatospectroscopic Method for Analyzing the Signals Generated During High-Performance Liquid Chromatography with Diode-Array Detection

A "chromatospectroscopic" technique has been developed to quantitate two compounds that coelute in high-performance liquid chromatography. The method uses a diode-array detector with Millenium 32 software to extract spectra at regular time intervals during the elution of the unique peak and recover spectral data (absorbance versus wavelength), which can then be processed using the Excel software package. The method is applied to mixtures of two coeluting UV filters. Both could be accurately quantitated even when the mixture consisted of 99.5% of one and only 0.5% of the other.