Chemometric‐guided Comprehensive Two‐Dimensional Gas Chromatography Analysis of Aucklandiae radix and Its Formulated Preparations

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.