Identification of Ophiopogonis Radix from different producing areas by headspace-gas chromatography-ion mobility spectrometry analysis

Abstract

Ophiopogonis Radix can be divided into Zhemaidong (ZMD) and Chuanmaidong (CMD). The main planting areas of ZMD are Cixi City and Sanmen county. The quality and price of Ophiopogonis Radix from different producing areas are different. In this study, the headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) method is used to rapidly identify ZMD and CMD. The method is also used to identify ZMD from Cixi and Sanmen by analyzing volatile organic compounds (VOCs). A total of 58 VOCs was obtained from ZMD samples with more abundant signals of which 41 were identified. The peak intensities of all VOCs in ZMD and CMD, Cixi and Sanmen data were averaged and then those VOCs whose peak intensities were distributed outside of mean ± 2 standard deviation (μ ± 2σ) were selected as characteristic markers. We selected 14 characteristic markers to establish the characteristic fingerprint of ZMD and CMD, among the 14 VOCs, ZMD contained more eucalyptus oil compounds than CMD, CMD contained more volatile aldehydes than ZMD. We selected 12 characteristic markers for the establishment of the characteristic fingerprint of ZMD from Cixi and Sanmen. The principal component analysis (PCA) results indicated that both ZMD and CMD or ZMD from Cixi and Sanmen could be effectively divided. The ZMD and CMD as well as ZMD from Cixi and Sanmen were evaluated by partial least squares regression-discriminants analysis (PLS-DA) resulting to be excellent chemical descriptors for sample discrimination. One hundred percent classification rates for both PLS-DA calibration and prediction models were obtained. These results provided a reference for the traceability of species and origin and market standard of Ophiopogonis Radix. PRACTICAL APPLICATIONS: Ophiopogonis Radix can be divided into Zhejiang Ophiopogonis Radix (ZMD) and Sichuan Ophiopogonis Radix (CMD). As far as ZMD is concerned, its producing areas mainly include the traditional planting areas (Cixi City) and new growth areas (Sanmen county). In this paper, the HS-GC-IMS method was adopted to analyze VOCs in Ophiopogonis Radix from different producing areas and then we screen out the respective characteristic VOCs of ZMD and CMD as well as ZMD from Cixi and Sanmen. These characteristic VOCs can effectively identify ZMD and CMD as well as ZMD from Cixi City and Sanmen country to provide a scientific basis for the origin identification of Ophiopogonis Radix.

Keywords: Chuanmaidong; Ophiopogonis Radix; Zhemaidong; headspace-gas chromatography-ion mobility spectrometry.