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nicotine
Значение термина nicotine в knolik
nicotine - Nicotine
nicotine - Nicotine is obtained from tobacco-leaves by the processes enumerated below:
(1) Infuse tobacco-leaves for 24 hr. in water acidulated with sulphuric acid, strain, evaporate to a syrup, add 1/6 of its volume of a strong solution of potash, and distil in an oil-bath at 288° F. (142° C.), occasionally adding a little water to assist the process and prevent the too great concentration of the solution of potash in the retort; next saturate the distilled product with oxalic acid, evaporate to dryness, digest in boiling absolute alcohol, evaporate the resulting tincture to a syrup, and decompose the oxalate of nicotine thus obtained by adding potash to it in a close vessel, and agitate the mass with ether, repeating the process with more ether until all the nicotine is dissolved out; lastly, distil the mixed ethereal solution in an oil-bath. At first ether comes over, then water, and lastly nicotine, which, towards the end of the process, assumes a yellowish tint. (Ortigosa.)
(2) This chiefly differs from the preceding by the concluding distillation being conducted in a retort, by the heat of an oil-bath, at the temperature of 284° F. (140° C.), in a current of hydrogen, for 12 hrs.; after which, byraising the heat to 356° F. (180° C.),the nicotine distils over pure, drop by drop. (Schlosing.)
(3) A tin vessel provided with 2 tubulures is filled with tobacco, which is previously damped with sodium carbonate. One of the tubulures admits a glass tube reaching nearly to the bottom of the vessel; the other is provided with a glass tube merely penetrating the cork. The vessel is made air-tight, placed in a boiling-hot steam bath, and a rapid stream of carbonic acid gas is passed through it, entering the vessel by the longer and leaving it by the shorter tube; the latter dips into a mixture of alcohol and dilute sulphuric acid. In this manner a large yield of perfectly colourless nicotine is obtained. In order to obtain the pure alkaloid, caustic baryta is added to the solution, the latter is evaporated to dryness, and the pure nicotine is extracted with ether. (Kirschmann.)
Рядом со словом nicotine в knolik
| narcotine | В начало буква "" буквосочетание "" | piperine |
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