Elaidin test

Olive oily which is obtained from the fruit of the olive tree, contains about 28 per cent of solid fat consisting of palmatin and a little arachidin. The rest is mostly olein. Substances present in smaller quantities are linolein, cholesterol, free fatty acids, and unsaponifiable matter. The oil is used as a salad oil, as a lubricant, in soap stock, and for other purposes. Its iodine value is 77 — 88. The elaidin test produces a solid mass within two hours. On account of its high cost it is frequently adulterated with cottonseed, peanut, lard, and other oils. 

As shown in Table I, a concentration of 20% or more crude trans--gyplure in formulations of cis-gyplurt is sufficient to cause inactivation the mechanism of this inactivation is not known. The trans- form was prepared by elaidinization of the cis isomer with nitrous acid. The propyl and butyl analogs of w-gyplure were completely devoid of activity in field tests. These results show that a cis double bond and an acetoxy group are necessary for activity (27). 

Boyle (1661) mentions that olive and almond oils become thick when acted upon by red fuming aqua fortis (which dissolves camphor), but the observation was not noticed imtil J. J. E. Poutet, a Marseilles apothecary, found that olive oil solidifies when shaken with a solution of mercury in nitric acid, and he proposed this as a test for olive oil. It was found, however, that other oils behaved similarly. Felix Boudet, a Paris apothecary, found that the mercury solution acts only when it contains free nitrous acid, and showed that a new substance is formed which he called elaidin, and considered to be a compound of glyceryl oxide and a new acid, elaidic acid. Laurent, by the action of nitric acid on oleic acid obtained eladaic acid. He isolated from the product what he called suberic, pimelic, adipic, and azelaic acids, which he formulated adipic pimelic and azelaic His pimelic acid... 

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