Coriandrum sativum L. (CSL), also called Chinese parsley in China, is a famous spice and is widely used in cooking due to its pleasant and delicate aroma. In China, CSL is not only an important spice in cuisine but is also a key traditional medicine. CSL is often used to treat headaches, measles, and rectal prolapse, and to prevent cancer.1) Numerous studies have been carried out regarding the chemical compositions and pharmacological activities of the essential oils of CSL fruits/seeds. [2][3][4][5][6][7][8] However, the fresh immature CSL plant is in fact the part most consumed by humans and most often used as medicine. The essential oils extracted from the CSL plant contain important bioactive compounds and have been proven to have antimicrobial [9][10][11][12] and anti-oxidative effects.
10)Several studies have been done on the essential oil composition of CSL plants grown in different places. [13][14][15][16][17][18][19][20] However, the identification of components was performed only through retention indices or direct similarity searches in the mass spectral libraries attached to the GC-MS instruments. So far, only a few components have been identified and the results may even be unreliable or may have been misidentified because heteroscedastic noise and overlapping peaks are always a problem in the analysis of essential oils. Using twodimensional gas chromatography combined with time-offlight mass spectrometry (GCϫGC-TOF-MS), Eyres et al. 18) detected and identified more components among the essential oils of CSL leaves in Fiji. However, the overlapping peaks are inevitable for the analysis of a complex sample even under optimum conditions. Furthermore, the GCϫGC-TOF-MS is expensive and not readily available at present. Therefore, methods that are more economical should be developed for the rapid analysis of the essential oils of CSL.In this study, the essential oils of CSL were separated and detected by GC-MS. Then a chemometric method called heuristic evolving latent projections (HELP) was applied to resolve the overlapped peaks. The pure chromatogram and spectrum of each component were accessible through the resolution of HELP method. Qualitative and quantitative analyses were then performed on account of the pure chromatograms and mass spectra.
ExperimentalMaterials Fresh plants of C. sativum L. were harvested in a local vegetable farm in Guangzhou, China. Undecane, linalool, nonanal, 1-hexanol, 1-dodecanol, dodecanal, 1-octadecanol, and 1-heptadecanol were purchased from Dr. Ehrenstorfer of GmbH (Augsburg, German) and for use as standards. The purities of the standards were all above 99.5%.Extraction of Essential Oil About 400 g of fresh whole CSL was cut into about 0.5 cm lengths at room temperature and then transferred immediately into a standard essential oil extractor to which 300 ml deionized water was added. The essential oils were extracted using the standard steam distillation method according to the Chinese Pharmacopeia.21) The total of 1.88 g essential oils were obtained with a yield of 0....