Sample Optimization of Fast Authentication of Concentrated Chinese Medicine Granules Using FTIR-ATR with Chemometrics

Concentrated Chinese medicine granules (CCMG) are the granular form of Chinese medicine that can be conveniently taken orally and have proven efficacy. In recent years, the quality of CCMG has raised public concern. Fourier transform infrared spectroscopy attenuated total reflection (FTIR-ATR) is a relatively simple, rapid and reliable analytical tool for Western drug verification, whereas application studies of FTIR-ATR for CCMG classification are very limited, possibly due to the higher chemical complexity in CCMG. To address this problem, FTIR-ATR coupled with chemometric and deep learning approaches are proposed. In this study, four species of CCMG, which share the same therapeutic function group, tonics, were selected for CCMG discrimination. The spectral data preprocessing, sample preparation method and spectral range selection for CCMG discrimination were optimized. This sample optimization analysis is essential for the subsequent deep learning analysis.