An approach to develop two-dimensional fingerprint for the quality control of Qingkailing injection by high-performance liquid chromatography with diode array detection.

An approach was proposed to develop two-dimensional fingerprint (2D fingerprint) by means of principal component analysis (PCA) of high-performance liquid chromatography with diode array detection (HPLC/DAD) data. The approach was applied to establish 2D fingerprints of various Qingkailing injections which were produced by different manufacturers and procedures. In comparison with common one-dimensional fingerprint (ID fingerprint) at fixed wavelength, 2D fingerprint compiled additional spectral data and was hence more informative. Principal component analysis of the 2D fingerprint data was performed in this study, and it led to an accurate classification of various samples on their manufacturers and procedures. The quality of Qingkailing samples was further evaluated by similarity measures and the same results were achieved. For comparison, four conventional ID fingerprints were also applied to the quality assessment for the same samples. Finally, we demonstrated that 2D fingerprint was a more powerful tool to characterize the quality of samples, and could be used to comprehensively conduct the quality control of traditional Chinese medicines.