Olibanum Resinoid

#### Olibanum Resinoid. True **Olibanum Resinoid **is obtained by extraction of the crude olibanum (see monograph **Olibanum) **with a hydrocarbon solvent, usually benzene, rarely petroleum ether, acetone, methylene di- chloride, etc. Benzene gives a high yield, but a dark colored product. The most important thing, however, is the choice of raw material. Although not an absolute rule, it is generally true that the Teddish-orange colored tears or lumps are poorer starting materials for perfumery use than are the yellowish or whitish lumps. The amount of sand, dust, woodsplinters, etc. should also be considered. A not infrequently used adulterant is the so-called **Dammar**** ****Resin**, derived from various **Shorea**** **species (not, as occasionally claimed, from **Dammara Orientalis**). Dammar resin is practically odorless and contains very little water-soluble matter. Accordingly, it does not form an emulsion with water when triturated. There is a perceptible difference in odor of olibanum resinoids from a hot (= refluxed) extraction process, and those from a cold process (i.e. stirring at room temperature). It is also logical that the manufacturers have switched from hydrocarbon solvents to ethyl alcohol. The latter solvent will mix with the small amount of water (moisture) which is always present in botanicals. This effect of the alcohol facilitates the penetration of the solvent into the particles of olibanum. Accordingly, fewer extractions are necessary and the extraction time is considerably reduced when ethyl alcohol is used in place of a hydrocarbon solvent. **Olibanum**** ****Resinoid**, when prepared by benzene-extraction, is a dark amber to dark orange or reddish-brown colored, almost solid, but somewhat plastic mass of non-pourable soft-extract consistency. It should contain all the available essential oil from the crude material, and accordingly, should yield about 7 to 10 percent of essential oil on a test distillation. Lighter colored resinoids are obtained in somewhat poorer yields by petroleum ether extraction. The odor of this resinoid is excellent. **Olibanum**** ****Resinoid**** **is a valuable fixative, but it also lends its own peculiar odor to the perfume (see odor description under **Olibanum**** ****Oil**** **and **Absolute**). Since the essential oil content is only about 8%, the **Resinoid of**** ****Olibanum**** **has a much more versatile application in perfumery than has the essential oil. However, in order to obtain a true physical fixative effect from olibanum resinoid alone, it would be necessary to use 4 to 6% or even more of this material. **Olibanum Resinoid **is often sold in a semi- liquid form, just pourable and handy for compounding without the harmful intermittent heating of the delicate product. The addition of 15 to 25% diethylphthalate or a similar, odorless, high- boiling solvent-plasticizer is a conventional and generally accepted treatment of olibanum resinoid, provided the content of solvent is clearly indicated on the label. See also **Olibanum,**** ****Olibanum**** ****Absolute,**** ****Olibanum**** ****Oil.**