Institution of Fingerprints of the TCM Wenyujin by GC-MS with Separation by SFE and Study on Their Categorization by the Systematic Clustering Analysis

Samples of the TCM wenjujin (WYJ) from 14 different batches grown in 8 cultural areas of the Rui'an city in Zhejiang Province were collected and pretreated by washing, freeze-drying and pulverizing to pass through the medicinal sieve with bore diameter of 0.425 mm, thus to otbain 14 analytical samples in powdery form. 30 g each of the 14 samples were taken and extracted separately by SFE technique under the optimized conditions of temperature at 35℃, of pressured under 15 MPa and with times of extraction of 30 min (static) and 90 min (dynamic). The extract was collected in 5 mL of CH₃OH and analyzed by GC-MS. Quartz capillary chromatographic column (HP-5ms) and programmed temperature elevation mode in the temperature interval of 50℃ to 220℃ were adopted in GC separation, and EI with scanning in the range of m/z from 50 to 650 was chosen for MS determination. As shown in the TIC chromatogram, more than 50 chromatographic peaks were obtained, among which 26 peaks in common with their retention times within 40 min were selected for further examination, using the peak of the compound numbered 16 with retention time of 17.12 min as the reference peak. Values of relative retention times α, percentages of peak areas S% and ΔS(Max) of the 26 peaks in common were calculated and their fingerprints were instituted. Based on the results obtained by GC-MS, and through comparing with the data given by the data base of NIST-14, the compounds giving the 26 common peaks were characterized. The fingerprints of the 14 samples from 8 cultural areas were studied comparatively by the systematic clustering analysis using the software of SPSS 16.0, and categorization based on the cultural areas of the Wenyujin was realized. Two Wenyujin samples obtained from the market were analyzed by the proposed method, with their components identified and their cultural areas recognized.