Second-order calibration-assisted LC-MS method for simultaneous determination of multiple active components and origin difference analysis of vinegar-processed cyperi rhizoma

In this work, a liquid chromatography-mass spectrometry (LC-MS) technique combined with alternating normalization weighted error algorithm (ANWE) method was proposed to realize the simultaneously fast quantification of 9 main active ingredients including isomers and origin difference analysis of vinegar-processed cyperi rhizoma (VCR). Overlapping peaks, similar mass spectra and fragment ions of isomers, and unknown matrix interference were all addressed by the proposed approach, which also yielded quantitatively and qualitatively acceptable results. Their average spiked recoveries range from 83.6% to 103.5%. It is worth mentioning that the proposed method can achieve accurate quantification of isomers α-cyperone and nocatone under simple chromatographic elution conditions. And the quantitative results of PARAFAC and ANWE algorithm were compared. Compared with the LC-MS/MS method, the quantitative results of ANWE-LC-MS method are not significantly different, and the required time is shorter. Meanwhile, the ANWE algorithm was used to resolve the 42 VCR's LC-MS fingerprints and determine the relative concentrations of components. Heatmap analysis reveals the difference in the content of the extracted variables in VCR samples, and the unsupervised hierarchical clustering analysis (HCA) method was used for their origins cluster. In addition, the partial least squares discriminant analysis (PLS-DA) method was adapted for the classification of Guang VCR and Non-Guang VCR accurately and five representative difference marker compounds were screened out with the variable importance in projection (VIP). In a word, this work is anticipated to serve as a reference for the development of quality standards for medications made from VCR or other Chinese herbs, as well as for the study of the origin discrimination.