title: Identification of sulfur fumed Pinelliae Rhizoma using an electronic nose.
abstract: BACKGROUND
  Pinelliae Rhizoma is a commonly used Chinese herb which will change brown during the natural drying process. However, sulfur fumed Pinelliae Rhizoma will get a better appearance than naturally dried one. Sulfur fumed Pinelliae Rhizoma is potentially toxical due to sulfur dioxide and sulfites formed during the fuming procedures. The odor components in sulfur fumed Pinelliae Rhizoma is complex. At present, there is no analytical method available to determine sulfur fumed Pinelliae Rhizoma simply and rapidly. To ensure medication safety, it is highly desirable to have an effective and simple method to identify sulfur fumed Pinelliae Rhizoma.
  
  
  METHODS
  This paper presents a novel approach using an electronic nose based on metal oxide sensors to identify whether Pinelliae Rhizoma was fumed with sulfur, and to predict the fuming degree of Pinelliae Rhizoma. Multivariate statistical methods such as principal components analysis (PCA), discriminant factorial analysis (DFA) and partial least squares (PLS) were used for data analyzing and identification. The use of the electronic nose to discriminate between different fuming degrees Pinelliae Rhizoma and naturally dried Pinelliae Rhizoma was demonstrated.
  
  
  RESULTS
  The electronic nose was also successfully applied to identify unknown samples including sulfur fumed samples and naturally dried samples, high recognition value was obtained. Quantitative analysis of fuming degree of Pinelliae Rhizoma was also demonstrated. The method developed is simple and fast, which provides a new quality control method of Chinese herbs from the aspect of odor.
  
  
  CONCLUSIONS
  It has shown that this electronic nose based metal oxide sensor is sensitive to sulfur and sulfides. We suggest that it can serve as a supportive method to detect residual sulfur and sulfides.
authors.affiliation: Life Science and Engineering College of South west Jiao tong University, Chengdu, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Life Science and Engineering College of South west Jiao tong University, Chengdu, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wan
authors.affiliation: Department of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Chu
authors.affiliation: Department of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
authors.forename: Wengang
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Jing
authors.affiliation: Department of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
authors.forename: Chunjie
authors.initials: C
authors.lastname: Wu
keywords: Electronic nose; Pinelliae Rhizoma; identification; sulfur