Specific rotation, and refractive index

The specific gravity, refractive index, and specific rotation given above are those recorded by Paolini and Divizia and are probably accurate since the a-santalol was prepared by regeneration from its strychnine phthalate. The values recorded for commercial santalol, prepared by fractional distillation, are as follows, and are the average values for the mixed santalols as they occur in sandalwood oil... 

Other properties of the substance giving an indication of its purity level will be included, such as (depending on its nature) maximum allowable quantities of insoluble matter, nonvolatile matter or residue on ignition, the pH of solution, density, melting point or boiling range, refractive index, and specific rotation. 

The temperature for measuring physical parameters, specific gravity, refractive index, and optical rotation is critical for obtaining accurate results. 

The Pharmacopea and the Essential Oil Association of the United States require the following analyses as an index of oil purity refractive index, optical rotation, refractive index and optical rotation of a 10% distillate, specific gravity, aldehyde content, evaporation residue and ultraviolet absorption spectrum (Kesterson et al. 157 and Sale 29). 

Harvesting time affects some chemical properties of oil, as is shown in Table 5.5. Furthermore, smaller differences have been observed in other properties such as specific gravity, refractive index and optical rotation in line with harvesting time (L6pez, 1995). 

Among the different analytical variables listed in Table 5.10, specific gravity, refractive index and optical rotation are widely used as quality indexes. The values of these properties allow us to estimate the (/-limonene content, general composition and adulterations in essential oils. Aldehyde content is also a widely used index in the characterization of essential oils, because it is a measure of the aromatic fraction values increase in mature fruit and decrease during fruit storage (Lopez, 1995). The UV absorption index indicates general quality and adulterations, and shows differences between the different types of essential oils (Lopez, 1995). 

It will be observed that high percentage of sulphur in the oil goes with high specific gravity, high refractive index, and laevo-rotation. 

Capillary gc/ms, hplc, nmr, ir, and uv are all analytical methods used by the terpene chemist with a good Hbrary of reference spectra, capillary gc/ms is probably the most important method used in dealing with the more volatile terpenes used in the davor and fragrance industry (see Flavors and spices). The physical properties of density, refractive index, boiling point, melting point of derivatives, and specific rotation are used less frequendy but are important in defining product specifications. 

The transition between crystalline and amorphous polymers is characterized by the so-called glass transition temperature, Tg. This important quantity is defined as the temperature above which the polymer chains have acquired sufficient thermal energy for rotational or torsional oscillations to occur about the majority of bonds in the chain. Below 7"g, the polymer chain has a more or less fixed conformation. On heating through the temperature Tg, there is an abrupt change of the coefficient of thermal expansion (or), compressibility, specific heat, diffusion coefficient, solubility of gases, refractive index, and many other properties including the chemical reactivity. 

Infrared and ultraviolet spectroscopy, including specific optical rotation, refractive index, and Raman spectral analysis... 

The description provided in this section should include, as applicable, information on the following (a) organoleptic properties (e.g., appearance, odor, taste) (b) solid-state form (i.e., the preferred crystalline polymorph) (c) solubility profile (limit data to aqueous solubility, pH effect, and at most one or two organic solvents (d) pH, pKa, or pKb (e) melting and boiling range (f) specific gravity or bulk density (g) spectroscopical characteristics such as a specific rotation, refractive index, and fluorescence and (h) isomeric composition. 

Note Oil obtained from early season distillation may show a carvone content as low as 25.0% and a correspondingly lower specific gravity, lower refractive index, and higher angular rotation. 

Diastercomers have different physical properties different melting points, boiling points, solubilities in a given solvent, densities, refractive indexes, and so on. Diastereomers differ in specific rotation they may have the same or opposite signs of rotation, or some may be inactive. 

An oil obtained from oleo-resin collected during 1911 had the following properties specific gravity, 0 8663 index of refraction, 1 4728 specific rotation [a]o = -i- 10 42. Another sample of the oil had a specific gravity of 0 8658 and an index of refiaction of 1 4727, and gave the following results on fractionation —... 

The oil contains f-o-pinene, and a sesquiterpene ( ) of specific gravity 0 9340, speciHc rotation - 21 24, and refractive index I 49fi0 at 16°. 

In 1899 Thoms isolated an alcohol from Peru balsam oil, which he termed peruviol. This body was stated to have powerful antiseptic properties, but has not been further investigated until Schimmel Co. took up the subject. The oil after saponification was fractionated, and after benzyl alcohol had distilled over, a light oil with characteristic balsamic odour passed over. It boiled at 125° to 127° at 4 mm., and had a specific gravity 0 8987, optical rotation -1- 12° 22, and refractive index 1-48982. This body appeared to be identical with Hesse s nerolidol, whilst in physical and chemical properties it closely resembles peruviol. The characters of the various preparations were as follows —... 

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