VOLATILE OILS

Ethereal Oils or Essential Oils or Essences

Volatile oils are also known as

Volatile Oils

They are generally complex products composed of mixtures of compounds of widely variant chemical characteristics.

Hydrocarbons

Alcohols

Aldehydes

Ketones

Phenols

Sulfur compounds

What are the important chemical components

Hydrocarbons

This is isocyclic series

pinene

camphene

limonene

bornylene

fenchene

dipentene

sylvestrene

phellandrene.

Example of Hydrocarbons

Alcohols

both in the free state and in combination with acids as esters

Linalool, geraniol, citroneol, terpineol, borneol, menthol and santalool.

Alcohols generally found in volatile oils are

benzaldehyde, cinnamic aldehyde, salicylic aldehyde, citral and citronellal

Aldehydes such as ____ are important in volatile oils

Ketone

the most important being camphor

Carvone

Fenchone

Thujone

Menthone

Other ketones

Anethol

Eugenol

Carvocrol

Saffrol

Chavicol

Phenols such as

with alcohols as esters

Acids sometimes in the free state in small quantities like acetic, propionic, butyric, valeric, benzoic, cinnamic and hydrocyanic acids but more often occurring in combination _____

Acids

sometimes in the free state in small quantities like acetic, propionic, butyric, valeric, benzoic, cinnamic and hydrocyanic acids but more often occurring in combination with alcohol and ester

Linalyl acetate

Bornyl acetate

Methyl acetate

Example of Acids

allyl isothiocyanate.

Sulfur compounds such as

Specific gravity

Rotatory power

Refractive index

Distilling range

Fractional distillation

Solubility

Physical constant for volatile oils

Westphal balance or pcynometer

Specific gravity is determined by the?

0.84 to 1.2.

Specific gravity values ranges from

orange, caraway, coriander, lemon, turpentine and rosemary oils.

Oils lighter than water are:

anise, cinnamon, clove, sassafras oils

Oils heavier than water include:

Polarimeter

Rotatory power is measured by

Rotatory power

Presence of adulterants such as alcohol or turpentine oil is determined by its influence in the _____

Abbe Refractometer

Refractive index – most commonly used instrument is the

1.46 to 1.61 at 20°C.

. Refractive index values ranges from

USP

____ provides the official method for determining the distilling range.

below 100°C

In fractionational distillation of the oil determines possible presence of alcohol which distills or boils

Rotatory power

A certain fraction of distilled oil may be used to determine presence of adulterants by determining the ______

organic solvents.

generally, volatile oils are soluble in

almost constant solubility with 90, 80 or 70% alcohol

Purity may be well established based on the fact that all volatile oils exhibit

turpentine oil, petroleum oils and fatty oils

Presence of adulterants such as _______ are slightly soluble thus producing turbidity.

ester content

alcohol content

aldehyde content,

ketone content

phenol content

The purity of volatile oils are definitely established by the determination of chemical constants such

well-fitted tightly stoppered-amber-colored bottles

temporarily prevented.

To store volatile oils properly, they should be kept in a ______ in a cool place. When mixed with a little alcohol the deterioration may be

five (5) to ten (10) percent

Volatile oils from citrus plants may be preserved by the addition of __________of fixed oils.

Steam distillation

The isolation is by ___ and measurement of the volume of the oil obtained

Steam distillation

A special distillation apparatus has been designed for the purpose whereby all the parts that will come in direct contact with the drug, volatile oil or steam are made of glass.

Steam distillation

The condenser is combined with the receiver to avoid as much as possible the loss of volatile oil vaporization and to provide direct reading of the volume of the oil.

4 to 8 hours

Complete extraction is effected by distillation for

Clavenger apparatus

Used apparatus for volatile oils

For oils lighter than water

For oils heavier than water

Types of clavenger appratus

Oils lighter than water

its volume is directly measured in the receiver which is provided with a lower portion graduated to tenths of a millimeter

Oil is heavier than water

the oil is transferred to a measuring cylinder and the water with whatever oil remains is placed in a separator. The rinsing together with the ethereal layer is allowed to stand so that the ether is evaporated and any oil left is added to the oil in the measuring cylinder

25 C

In oil is heavier than water volume of the oil is measured at

acetates of alcohol

Esters are in the form of

alc. KOH

free alcohol

potassium salt

Esters are refluxed with____ saponified and yield the ____ and the _____ of the acid

Ester value

s the no. of mg of KOH required to saponify 1gm of the sample.

Menthol

peppermint oil

Borneol

Rosemary oil

Alcohol content

Free and combined as esters

Alcohol content

Sufficient to prove the purity and value of the volatile oil.

Alcohol content

The determination consist of the conversion of the free alcohol to its acetate ester and saponification of the freshly produces acetate and original acetate with standard alcoholic potassium hydroxide.

acetate and original acetate

In alcohol content the determination consist of the conversion of the free alcohol to its acetate ester and saponification of the freshly produces ________ with standard alcoholic potassium hydroxide.

Acetylization flask

provided with an air condenser to condense any vapors of the volatile oil and the acetic acid that is produced.

asbestos board

decomposition of the oil

The acetylization flask should be heated over an ____ to avoid the _____

Bisulfite method

Hydroxylamine method

In aldehyde content, there is two method

Aldehyde content

based on the principle that the aldehydes and ketones found in volatile oils form soluble addition products with sodium bisulfite and that these products being soluble in water leave a certain volume of oil which do not contain aldehydes or ketones.

Assay of volatile oils which do not contain constituents other than aldehyde and ketones and is not applicable for volatile oils which contain aldehydes in very small amount

Bisulfide method is limited only for what assay?

aldehyde or ketone

By finding the difference between the volume of original oil and that of the residual oil, the volume of _____ is determined

original oil and that of the residual oil

By finding the difference between the volume of _____, the volume of aldehyde or ketone is determined

106.1 milligram of benzalde

1 mL of 1-N NaOH is equivalent to

Benzaldehyde in the oil to form benzaldoxime with the liberation of hydrochloric acid

Hydroxlamine hydrochloride reacts with? to form what?

Phenol content

Volatile oils that contain ____ when shaken with solution of potassium hydroxide diminish in volume because of the steady solubility of the phenol constituents in alkali leaving the non-phenolic portion of the oil undissolved.

potassium hydroxide

steady solubility of the phenol

non-phenolic

undissolved

Volatile oils that contain phenols when shaken with solution of ____ diminish in volume because of the _____ constituents in alkali leaving the _____ portion of the oil _____

Phenol content

The method and principle is identical to the bisulfite method for the assay of aldehyde and ketones except that the solution used is either sodium or potassium hydroxide.

Phenol content

The method and principle is identical to the bisulfite method for the assay of aldehyde and ketones except that the solution used is either sodium or potassium hydroxide.

sodium or potassium hydroxide.

Phenol content is the method and principle is identical to the bisulfite method for the assay of aldehyde and ketones except that the solution used is either ________

Assay of volatile oils in spirits

based on the isolation of the oil from the other components of the spirit by the use of an immiscible solvent and measuring the volume of the liberated oil.