Amyl Alcohol

AMYL ALCOHOL, C₅H₁₁OH, a byproduct of distillation. Specific gravity 0.8142 (15°), boiling point 130°, refractive index 1.407. It is a colorless liquid with an unpleasant taste and odor; it strongly irritates the respiratory organs. It mixes with ethyl alcohol, ether, and xylene in any proportions, but dissolves only 2% of water. It does not dissolve celloidin, which is why it is used instead of carbol-xylene for dehydrating celloidin sections (see Histological technique). As an occupational poison, it is encountered in the alcohol and vodka industry and in the chemical industry (production of amyl nitrite, aniline dyes, valeric acid, fruit essences, etc.). Inhalation of amyl alcohol vapors causes headaches, a scratchy throat, shortness of breath, and coughing. Prevention consists of hermetically sealing equipment and local exhaust of vapors. Fermentation amyl alcohol, obtained in amounts of 50 to 80% from fusel oil by fractional distillation, is a mixture of two isomers that are difficult to separate: 1) α-isoamyl alcohol (CH₃)₂CH-CH₂-CH₂OH—optically inactive, specific gravity at 20° is 0.8104, boils at 130°, causes coughing when inhaled; 2) β-isoamyl alcohol (CH₃)(C₂H₅)CH-CH₂OH—levorotatory, [α]_D = -5.9°; specific gravity at 15° is 0.816; boils at 128°; does not cause coughing when inhaled; α-alcohol is usually contained in amyl alcohol from 70 to 85%, β-alcohol from 15 to 27%, but in amyl alcohol from molasses—up to 60%. Fermentation amyl alcohol boils at 129–131°; soluble in 40 parts of water; specific gravity at 15° is 0.814–0.816. Amyl alcohol is used for the manufacture of esters—pear, apple, and other essences; valeric acid is also prepared from amyl alcohol, the salts and esters of which have medical significance (Zinc valerianate, Validol, etc.). In industry, amyl alcohol is used as a solvent in the manufacture of varnishes and paints. Amyl alcohol is approximately 10 times more poisonous than ethyl alcohol: 0.5 g of fusel oil causes a headache, a feeling of being stunned, and stomach pain; the depressing effect on the heart and on the cerebral vessels is particularly dangerous. Amyl alcohol is constantly found in alcoholic beverages, in grape wines, and in cognac; in vodka and spirit purified by the column method, fusel oil is usually absent. In forensic-chemical investigations, amyl alcohol serves for the extraction of certain alkaloids, as well as "aniline dyes." The determination of amyl alcohol in beverages can be carried out in the distillate by reaction with salicylaldehyde (1 g) and sulfuric acid (cherry-red coloration); quantitative determination of amyl alcohol is most often performed according to Röse.