Chemometric-guided Comprehensive Two-Dimensional Gas Chromatography Analysis of Aucklandiae radix and Its Formulated...

An integrated strategy combining comprehensive two-dimensional gas chromatography with chemometrics was established to characterize Aucklandiae radix (AR, Mu-xiang) and its complex formulations. By employing contour visualization, intelligent deconvolution, and in-silico retention index prediction, the method effectively resolved severe co-elution, separating at least five components from single peak vertices. A total of 55 characteristic compounds were identified in the AR essential oil. Comparative analysis revealed that AR and its substitute, Vladimiriae radix (Chuan-Muxiang), shared 21 components, while the former possessed 12 unique constituents compared to 47 in the latter. Chemical divergence was even more pronounced in other substitutes. Furthermore, although costunolide is a major component in the herb powder, it constitutes only 0.4% of the essential oil; thus, dehydrocostus lactone (or dihydrodehydrocostus lactone) and 1,8,11,14-heptadecatetraene were selected as quality markers. The application of these markers to Xiangsha-Yangwei pills from eight manufacturers yielded similarity values of 0.22-0.76. This quantitative profiling revealed significant quality inconsistencies, including the absence of critical components, demonstrating the method's utility for the comprehensive quality assessment of traditional formulas.