eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2020-09-25 13 03 1339 1350 10.13005/bpj/2003 34924 article Chui-Man Lo 1 Jie Han 1 Emily S. W. Wong 1 Department of Science, School of Science and Technology, The Open University of Hong Kong, Ho Man Tin, Kowloon, Hong Kong SAR Aromatheraphy refers to the application of essential oils to treat diseases. Essential oils come from natural plants, with characteristic odor. Apart from aromatherapy, they had been used for thousands of years in many home products, such as cosmetic and mosquito repellents. Due to their different active ingredients, each essential oil has slightly difference in their functions. For example, Chamomile oil extracted from Chamomilla recutita can be used in anti-ulcer, anti-inflammatory, antimicrobial and has a function of sedation; Citronella oil extracted from Cymbopogon nardus is mainly used as mosquito repellent; Jasmine oil extracted from Jasminum officinale can be used for antidepressant and antiseptic; and Geranium oil extracted from Pelargonium graveolens can reduce inflammation, treat acne and alleviate anxiety. In our study, the essential oils were extracted from the corresponding plants by either steam distillation or Soxhlet extraction, and the chemical analysis of their active ingredients were performed by GC-MS. Most of the components in essential oils belong to monoterpenoids, sesquiterpenoids or oxygenated terpenes. https://biomedpharmajournal.org/vol13no3/chemistry-in-aromatherapy-extraction-and-analysis-of-essential-oils-from-plants-of-chamomilla-recutita-cymbopogon-nardus-jasminum-officinale-and-pelargonium-graveolens/ Aromatheraphy Essential oil Steam distillation Soxhlet extraction GC-MS analysis