The determination of higher alcohols in spirits. I / by Philip Schidrowitz and Frederick Kaye.

  • Schidrowitz, Philip.
Date:
[1905]
Catalogue details

Licence: In copyright

Credit: The determination of higher alcohols in spirits. I / by Philip Schidrowitz and Frederick Kaye. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Purification of Materials; Ethylic Alcohol.—The “pure absolute alcohol” of commerce was subjected to fractional distillation in a flask provided with a Young’s “ rod and disc ” head until the resultant product showed no aldehyde reaction, was entirely neutral, and gave satisfactory blank tests with both the Allen-Marquardt and the colorimetric processes. Carbon Tetrachloride.—This was first shaken with water, then boiled for several hours with chromic acid mixture, subsequently washed first with water, then with very dilute sodium bicarbonate, and finally with distilled water until neutral. The product so obtained was then further purified by distillation. Amylic Alcohol.—Several methods of purification of the “pure ” amylic alcohol of commerce (B.P., 128-132) were tried, but the following was finally adopted as being most satisfactory. The alcohol was successively shaken with dilute sulphuric acid, water, warm milk of lime, then filtered and allowed to stand overnight over solid quicklime, distilled over the latter, treated with freshly ignited sodium sulphate, distilled over the same, and finally fractionated by means of a Young’s “ rod and disc ” apparatus. By this means we were able to obtain a product which distilled entirely within half a degree, namely, at 129-5 to 130° C. Apparatus.—We found it a matter of very considerable difficulty to obtain an apparatus for the prolonged boiling, in the Allen-Marquardt process, of the carbon tetrachloride solution with the chromic acid mixture which was absolutely air-tight, and would permit of prolonged boiling without loss. Rubber cannot be used, and ordinary corks were found very unsatisfactory. In the same way, neither an ordinary (24-inch) Liebig nor a five-bulb condenser was capable of preventing all loss. Finally we were compelled to resort to an all-glass apparatus, consisting of a 300 c.c. Jena glass Erlenmeyer flask very carefully ground in to a 24-inch Liebig condenser, the central tube of the latter being fitted throughout its length with a Young’s “rod and disc.” This effectually prevents the slightest loss, and our experience is that an apparatus of this kind, if properly made, lasts for a very considerable time without cracking, and is useful for many other purposes in the laboratory, notably for the saponification of the ethers in spirits. Otherwise the apparatus used needs no special description. A. The Beckmann Process. This process consists substantially in a separation of the higher alcohols from the spirit (to which a certain amount of calcium chloride has been previously added) by means of carbon tetrachloride, converting the higher alcohols so isolated into their nitrites by means of nitrous acid set free by the interaction of sodium nitrite and sodium bisulphate, removing the excess of nitrous acid with sodium bicarbonate, decomposing the nitrites with sulphuric acid, and finally titrating the nitrous acid so obtained with permanganate. Our first experiment was made (following Beckmann’s instructions minutely in every detail) with a blank solution of 48*7 per cent, alcohol (by volume). The final titration in this case required some 300 c.c. permanganate, corresponding roughly to 0*8 per cent, of amylic alcohol. This was obviously an impossible result, but blank tests made with the materials (carbon tetrachloride, ice, sulphuric acid, etc.) employed failed to yield any explanation. It became therefore necessary, in the