Identification and quantification of overlapped peaks in liquid chromatography with UV diode array detection using an adaptive Kalman filter

A method for the identification and quantification of overlapped peaks in liquid chromatography with UV diode array detection is reported. The adaptive Kalman filter, which is optimized using simplex optimization, can detect low levels of isomeric impurities. The filter optimization is based on the maximum information yield from the filtering procedure, and is capable of compensating the model errors. This approach is combined with the commercially available software to result in a complete method for chromatographic peak analysis. A mixture of two isomers, chrysene and benz(a)anthracene, has been evaluated. This method can detect as low as 1 μM benz(a)anthracene in a 121 μM chrysene solution, and 1 μM chrysene in a 106 μM benz(a)anthracene solution. Both, identification and quantification of the major and minor components have been achieved. For the overall method, the prediction errors are within 2% for the major components and within 10% for the minor components. If the reference spectrum of the minor component is unavailable, this filter can also predict the concentration of the major component within an error of 7%. The reliability of this method has been tested by the second isomeric system, a mixture of benzo(k)fluoranthene and benzo(b)fluoranthene. This method is valid for highly overlapped peaks even when the chromatographic resolution is zero, but an overlap-free region is required in the spectra.