Spectral correlation of high-performance liquid chromatography-diode array detection data from two independent chromatographic runs: Peak tracking in pharmaceutical impurity profiling

A novel qualitative analytical method for peak tracking in impurity profiling control by the correlation of spectra was established. Two-dimensional (2D) standard spectrochromatographic data produced by high-performance liquid chromatography with diode array detection (HPLC-DAD) were compared with sample data to develop two-dimensional chromatographic spectral correlative maps. Taking full advantage of separation efficiency of HPLC and spectral specificity of the analytes, the method was successfully used to recognize impurities in quinolone antibacterials, when in combination with relative retention times (RRTs). For the comparison of spectra was expanded to three-dimensional space, simultaneous identification of the chromatographic peaks can be obtained rapidly without preparation and injection of a reference solution, even when the mobile phase changed or the peaks of multi-component samples overlapped.