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Synonyms : Rosin; Rosina; Colophonium; Resin; Amber-resin, Gum rosin, pine-resin.
Biological Source: Colophony is the residue left after the distillation of the oil of turpentine from the crude-oleoresin obtained from various species of Pinus
Family: Pinaceae
Geographical Source: It is prepared in North America, Northern Europe, Pakistan and India.
Morphological Characteristics:
Colour - Pale yellow to yellowish brown or amber colour.
Odour-Faint and terebinthinate.
Taste - It occurs in the form of angular, translucent masses of various sizes.
Extra Features
Colophony is brittle and readily fusible with glossy appearance
Solubility
It is insoluble in water but soluble in alcohol, carbon disulphide, chloroform, ether, many fixed and volatile oils, glacial acetic acid and in light petroleum.
Chemical Constituents:
Colophony contains mainly
Resin acids which are unsaturated and hence reactive.
About 90% of this is abietic acid.
Esters of oleic acid and resin acids.
0.5% volatile oil;
5 to 6% resenes.
Other acids in the colophony are sapinic acid and pimaric acid.
Unsaponiliable matter of colophony, which constitutes about 3 - 10%
Chemical Test for Identification
Take 1 gm of Colophony and dissolve in 10 ml of acetic anhydride by gentle heat and add a drop of sulphuric acid, bright red colour changing to violet is produced.
Alcoholic solution of colophony is acidic to litmus.
Dissolve colophony in light petroleum ether and double the volume with dilute solution of copper acetate, petroleum layer takes emarald green colour (due to the copper salt of abietic acid).
Uses:
Stimulant and diuretic.
It is ingredient of certain plaster masses and collodions.
In the preparation of ointments.
Rapin-esters are used as protective coatings like polymers.
In the preparation of varnishes, insulating compounds, soaps; printing inks, paper sizing in the preparation of floorings, soldering compounds, mastics and pressure, Sensitive Additives
Storage
Colophony should be stored in the unground condition in well filled, well-closed containers away from light and in cool places.
In the powder form, it gets oxidised quickly and looses its solubility in light petroleum and gets increased in the weight and hence, it should be stored properly.
Adulterants
Colophony is adulterated with black resin or apic resin. However, both of them can be confimed by solubility
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