The ancient Egyptians extracted essential oils from herbs, fruits, vegetables, grasses, flowers and other plants, which were used to treat diseases and worship gods, and also as preservatives for mummies. The Greeks learned from Egypt and used essential oils for cosmetics, medical treatment and prevention of infectious diseases. In BC 100, the Romans massaged with essential oil. With the Crusades, the knowledge of spices and essential oils spread all over Europe, and the17th century was the peak of aromatherapy. /kloc-in the 0 th and 9 th centuries, modern medicine and pharmacy rose, so aromatherapy declined. After World War II, because of the increasing side effects of drugs and many unexplained civilized diseases, the value of aromatherapy in promoting human health, activating cells and protecting spirit and emotion was re-emphasized. Therefore, in recent ten years, France, Britain, Italy and other countries have revived the study of aromatherapy. Experts pointed out that the medical efficacy of aromatherapy and aromatic essential oil is worthy of attention, but in order to avoid unwittingly delaying the illness and being in poor health, it is necessary to consult professional medical personnel before using it. 1937, the therapy using natural essential oil was officially named "aromatherapy". There are many popular methods to identify essential oils, especially in Taiwan Province province, using tissue paper and water-soluble method. However, they are questioned by some domestic experts. This paper introduces a simple and effective identification method of 10, hoping to play a role in attracting jade. We suggest that you should summarize some practical methods in your own continuous purchase. 1, depending on the price, plant essential oil is mainly extracted by distillation. General 100 kg of flowers and plants can extract 2~3 kg of essential oil, so the price of real essential oil will not be too cheap. The market reference price is: common essential oils such as orange and tea tree oil are about 10m/400- 1300 yuan, and precious essential oils such as sandalwood are about 65,438 yuan. I suggest you go to a regular shopping mall or a professional beauty agency to buy it. If some self-proclaimed imported essential oils are cheaper than domestic products, their authenticity is self-evident. 2, see usage Except for a few varieties such as roses, tea trees, lavender, the vast majority of pure essential oils can not be directly used for the skin, otherwise it will cause burns and peeling. If the essential oil introduced to you by the merchant says that it can be used directly on the skin, and it is also said that it is pure essential oils, then there is a problem. We must distinguish between base oil and essential oil. Some base oils in the name of essential oils have really deceived many people. 3. Smell: Most pure essential oils tastes soft and mellow, because 65,438+000% of them are extracted from plants, so pure essential oils has an indescribable taste of natural plants (although the smell is not necessarily good). The essential oil blended with essence has a pungent taste, and long-term use of this essential oil is harmful. When I first entered the nose, the taste was not very strong, but it had a aftertaste. At the back of the head, there will be a feeling of wilderness. Everyone feels different about him, and his taste is different. 4. Fumigation A. After fumigation of unilateral essential oil for several times, if greasy residue (different from scale) is left, it means that it has been diluted with vegetable oil or mineral oil; If there is any crystal residue, it is probably diluted with ethanol and ether, which is self-evident. B, take a glass of water and drop a drop of essential oil. The real pure essential oils generally volatilizes quickly, and then there is no residue. If diluted with vegetable oil or mineral oil, the volatilization speed will be much slower, and oil stains will often be left on the water surface. 5. See that the packaged essential oils are generally stored in dark sealed small glass bottles with special strong acid and alkali resistant caps to prevent the infiltration of sunlight and oxygen, so that the essential oils do not volatilize and deteriorate. In a good preservation environment (room temperature), it can generally be preserved for two years, and the essential oil with good quality can be preserved for 4-5 years. Citrus essential oil can also be stored for 1-2 years. Bottled products with drippers are generally 3%- 10% diluted essential oil, not pure essential oils. The label of pure plant essential oil should indicate the purity. 6, look at the specific gravity Generally speaking, the specific gravity of grass essential oil is the lightest, and it will quickly disperse when dropped into a glass of water, and the water surface will be oily; Resin essential oil is the heaviest molecule. If you drop it into a glass of water, it can completely fall into the bottom of the cup and should not dissolve in water. But both of them will distribute two kinds of essential oil molecules under the water surface. Although they are insoluble, they have not penetrated into the whole glass of water. Citrus, a special flower essential oil, is heavier than water and insoluble in water. Similar to resin essential oil, it will drop directly into the bottom of the water, and you can see crystal clear dark green essential oil beads. 7. Look at the color, such as German citrus, because it contains a very precious ingredient "Blue Classic", which is dark blue in color and has a strong medicinal taste. If what you bought is colorless, you must have been cheated! 8. Look at the purer the essential oil, the stronger the penetration. Gently rub the tested essential oil on the back of your hand or the inside of your wrist, and then massage with your fingertips several times. Good quality essential oil will be absorbed in an instant and will not leave shiny oil on the skin. You can also observe whether the essential oil contains impurities. For example, the essential oil extracted from the peel by the traditional freeze pressing method will leave a little residue, which will make the product quality worse. Because of the molecular structure, the volatile speed of essential oil is relatively fast, and it will play out within 5- 10 minutes, which shows that it is relatively pure. Volatile slowly, not necessarily pure essential oils. 9. Look at the degree of integration. Pure essential oil is very lipophilic. When it is mixed in base oil, it will be completely fused and the molecules of the two will be completely combined. Otherwise, the essential oil contains chemical synthesis or wax, which makes it impossible to completely blend with the base oil. 10, depending on the origin of the plant from which the essential oil is extracted, the quality will be different due to different origins. Land quality, temperature, humidity, planting level, harvesting time and treatment methods all directly affect the quality of its essential oil. Therefore, we should pay attention to the origin of plants when choosing essential oils. List the origin of some essential oils, such as rose essential oil in Bulgaria.