Rapid Discrimination of Codonopsis Radix Harvested from Different Regions in China Using an Electronic Nose Coupled with Chemometrics

Codonopsis Radix is a well-known and widely used traditional Chinese Medicine (TCM) around the world. It is produced from different regions such as Wen County and Weiyuan County of Gansu Province, China, which are considered as the sources for the best quality. Codonopsis Radix produced from Wen County is called Wen Dang, while the herbal medicine produced from Weiyuan County is called Baitiao Dang. To rapidly and conveniently discriminate between Wen Dang and Baitiao Dang, a rapid and robust method was developed using an electron nose coupled with chemometrics. The odors of samples of Wen Dang and Baitiao Dang were recorded using an electronic nose. Principal component analysis (PCA), discriminant factor analysis (DFA), and soft independent modeling of class analogy (SIMCA) were performed for analyzing the fingerprints of odors from Wen Dang and Baitiao Dang. The results demonstrated that Codonopsis Radix produced from the two locations could be successfully differentiated using an electron nose coupled with PCA, DFA, and SIMCA. The electronic nose requires minimal sample preparation, and it is nondestructive, fast, accurate, and reproducible. Coupled with chemometics, the electronic nose can be potentially of a great practical value in identification and quality control of traditional medicines.