Development of a novel UHPLC-UV combined with UHPLC-QTOF/MS fingerprint method for the comprehensive evaluation of Nao-Luo-Xin-Tong: multi-wavelength setting based on traditional Chinese medicinal prescription composition

A novel UHPLC-QTOF/MS fingerprint method was developed based on multi-wavelength detection using an ultraviolet detector and the analysis of common peaks by the mass spectrometry technique, and was validated in the quality evaluation of a traditional Chinese medicinal prescription: Nao-Luo-Xin-Tong (NLXT) decoction. NLXT is a classical traditional Chinese medicine (TCM) prescription that has been widely used to treat strokes for over fifty years in the First Affiliated Hospital of Anhui University of Chinese Medicine. In order to obtain the overall chemical material information of NLXT, reliable UHPLC-UV methods at four characteristic wavelengths (203 nm, 254 nm, 320 nm and 403 nm) were developed and 8 representative constituents were chosen. Good separation was achieved on an Agilent – Eclipse Plus C18 column with a gradient elution at a flow rate of 0.2 mL min−1 within 60 min. The chromatogram data of twelve batches of NLXT decoction were analyzed by “Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine” (2012 Version). Subsequently, a common pattern was established and the similarity was evaluated. The results showed that 40, 19, 13 and 9 common peaks were obtained in the chromatograms at the wavelengths of 203 nm, 254 nm, 320 nm and 403 nm, respectively, and the similarities of the twelve batches of NLXT decoction were all above 0.97. In addition, the novel UHPLC-QTOF/MS technique in both positive and negative ion modes was applied in the identification and detection of common peaks. Based on the results, 36 common peaks out of 47 common peaks were identified or tentatively characterized based on their exact molecular weights, fragmentation patterns and literature data. In other words, the novel UHPLC-QTOF/MS fingerprint method not only gives essential data for identification of NLXT decoction but also provides a reference for the quality evaluation of traditional Chinese medicinal prescription.