Such situations, general LC fingerprint technique wasn’t easy to achieve satisfactory results. According to the rule of the multi wavelength mix method, multi wavelength LC fingerprint natural product library may better reflect more chemical structure within the products than common LC fingerprint with single short wavelength detection. From Figs. 2 and 3, the basic process of variable wavelength LC fingerprint fitting of R. isatidis was displayed in front of us using sample no. 8 on your behalf of 11 source R. isatidis examples. Among UV 230, 310 and 277 nm, standard uncertainty were very clear at 230 nm in Fig. 2, but top signs were fairly strong beneath the wavelength detection. The situation is the opposite at 310 nm, and 277 nm indicators were between the two, and there were some sign peaks only in the long wavelength instead of in the short wavelength. In this study, a whole retention time was split into two retention time segments: 0 70 min part and 70 110 min part. About 0 70 min top indicators were obtained at UV 230 nm. After 70 min were adopted under Endosymbiotic theory UV 310 nm the peak indicators. Through recombining two chromatogram segments corresponding to their respective retention time segments together and subtracting corresponding indicators of blank trials, 11 adjustable wavelength LC fingerprints were eventually created by the usage of the Origin 7. 5 application. The ultimate LC fingerprints of Dtc. isatidis extracts were excluded from UV absorption disturbance of solvents, cellular cycle or its gradient elution. After analysis and evaluation of these 11 LC fingerprints, there have been 24 common peaks selected in these PFT alpha fingerprints. 3. 2 Method agreement The separation of the 24 popular peaks was achieved by using LC approach with simple linear gradient elution at 230 and 310 nm. The typical relative retention times and peak areas of the 24 common attribute peaks regarding the reference peak at retention time 58. 1 minute are shown in Dining table 2, and there have been three replicates in the test analysis. The LC assay precision was stated by RSD value. Intra day variation of the retention times and peak areas of the characteristic peaks was o0. 1 and o3. Five full minutes respectively by considering the six replicates on the same day. Inter day variation of the retention times and peak areas of the characteristic peaks established in three successive days were acceptable. 3. 3 Standardization of LC fingerprint of R. isatidis The LC fingerprints were matched quickly by usage of the Similarity Evaluation System for Chromatographic Fingerprint of TCM. In accordance with retention times of seven common chromatograms, syringic acid, anthranilic acid, benzoic acid, salicylic acid, tryptanthrin, indigo and indirubin were well settled and eluted with retention times of 12. 7 minimum, 14. 6 minimum, 23. 2 minimum, 35. 4 minimum, 67. 1 minute, 79.