Analyzing the effect of different storage times and different processes on the volatile components in Shenling Baizhu powder by HS-GC-IMS combined with multivariate statistics

Aim: this study aimed to examine the effect of different storage times (0, 7, 24, 57, and 119 days) on the volatile components of Shenling Baizhu powder across different preparation processes (Pharmacopoeia, ultra-micro pulverization-pulverization, and microparticle design methods). The findings offer insights to guide quality control measures for Shenling Baizhu powder. Methods: gas chromatography-ion mobility spectrometry (GC-IMS) was employed to ascertain the volatile components in Shenling Baizhu powder at various storage times across different preparation processes. In addition, the study compared the dynamic changes of these components under different conditions. Principal component analysis (PCA) and orthogonal partial least-squares discrimination analysis (OPLS-DA) were conducted using SIMCA-P19.0 software to analyze differences among these volatile components. Results: the volatile components identified by GC-IMS comprised 52 monomers and dimers and polymers of some substances, primarily including aldehydes, esters, terpenes, nitrogenous compounds, and ketones. Fingerprint spectra revealed significant differences in the types and quantities of volatile components in Shenling Baizhu powder at different storage times under different processes. PCA indicated negligible differences in the types of volatile components among samples prepared using different processes. An OPLS-DA model was developed to distinguish storage times and identify characteristic markers. In addition, 22 volatile components with variable importance for the projection (VIP) > 1 were identified, significantly contributing to the discrimination of storage times for Shenling Baizhu powder. Overall, the content of volatile components in the samples gradually decreased with prolonged storage time. Samples prepared using the Pharmacopoeia method exhibited the most significant decline, whereas those prepared using the microparticle design method showed the least reduction in volatile components. Conclusion: HS-GC-IMS effectively captures the changing trends of volatile components in Shenling Baizhu powder across different preparation processes and storage times. This analysis provides a reference for quality control and process optimization in the production of Shenling Baizhu powder.