Distillation, apparatus methods

In the thermal procedure C the substrate is heated at 230-250°C under reduced pressure (in a Kugelrohr distillation apparatus) (method C ) ° or heated in DMF at 70-100°C in the presence of an additional alkali metal halide (method The tellurium moiety is isolated as diphenyl ditelluride, despite the formal formation of phenylteUurenyl halide. 

Ether. The most satisfactory method for the removal of (diethyl) ether is either on a steam bath fed from an external steam supply or by means of an electrically-heated, constant-level water bath (Fig. 77, 5, 1). If neither of these is available, a water bath containing hot water may be used. The hot water should be brought from another part of the laboratory under no circumstances should there be a free flame under the water bath. It caimot be too strongly emphasised that no flame whatsoever may be present in the vicinity of the distillation apparatus a flame 10 feet away may ignite diethyl ether if a continuous bench top lies between the flame and the still and a gentle draught happens to be blowing in the direction of the flame. 

Much time can be saved by the use of the steam distillation apparatus described, especially when large quantities have to be handled. The above directions avoid the use of extraction methods, which not only consume more time but may lead to appreciable losses of material. If the downward condenser is of iron, the apparatus is even more. efficient and the time for the steam distillation is halved. 

Method OP Neat n-dodecylphenyltellurium dibromide (0.53 g, 1.0 mmol) is heated at 230-250°C at 3 torr using a Kiigelrohr distillation apparatus. A colourless liquid distills which is identical to n-dodecyl bromide ( H NMR and GLC analysis) [0.25 g, (90%)]. (A red-brown residue seems to be mainly PhTeBr and on standing exposed to the ambient atmosphere solidifies to a grey solid PhTe(0)Br and the starting dibromide by IR and combustion analytical data.)... 

Indole. Russian patent 306, 126 (1971). Note See the making precursors section of this book for an explicit method of producing methylindole in good yield. Add 26 ml of 0.77 N NaOCl to a stirred suspension of 1.9 g of orthocarbamoyl cinnamamide in 50 ml of methanol and heat in a distillation apparatus until no more indoles is distilled off (use an indole test) or just heat at 40° for 2 hours. Extract the distillate with chloroform, dry with most any drying agent, except calcium chloride, and evaporate the solvent (CHCb) off from the remaining indole. Yield 45%. 

It is very common to combine methods in obtaining aroma isolates. The simultaneous distillation/extraction method previously described is an example. Another popular combination method initially involves the solvent extraction of volatiles from a food and then high-vacuum distillation of the solvent/aroma extract to provide a fat-free aroma isolate. This technique is broadly used today to provide high-quality aroma extracts for numerous purposes. The apparatus used in solvent removal has been improved upon to reduce analysis time and efficiency the modified method is termed solvent-assisted flavour extraction (SAFE) [16]. 

Porta published in 1608 at Rome a work on distillation, its methods, apparatus and applications, which is of interest as giving a more comprehensive view of the applications of distillation in the sixteenth century than is found in any other work of the period. Methods and apparatus for distillation had been described from very early times, by Zosimus, pseudo-Geber, Brunschwylc, Biringuccio, Agricola and many others for particular applications. 

This treatise of Porta s, which is very different in plan and content from the book on distillation in his earlier work, is divided into nine books, dealing successively with the kinds of distillation, the methods and apparatus for distillation in general, furnaces, retorts, condensers, etc. with the preparation of distilled perfumed waters, from roses, violets, myrtle, lavender, jasmine, lilies, etc. with... 

Since equilibration sometimes takes days or weeks, the isopiestic method is not suitable for unstable compounds or compounds with appreciable volatilities. Also, long equilibration times require leak-free and grease-free apparatus. Another design for an isothermal distillation apparatus is given in Fig. 9.10. 

Metals, especially copper, zinc and lead, may be found in spirits in small quantities derived from the distillation apparatus or the storage vessels. They are detected and determined by evaporating a sufficient quantity of the liquid, incinerating the residue and treating the ash by the ordinary methods of qualitative and quantitative analysis. 

The concurrent method allowed aqueous beef slurries to be irradiated (in the presence of oxygen) and at almost the same time volatile components were removed at pressures of about 25 mm. of Hg and at a temperature around 32°-36°C. When irradiation was carried out before distillation, the cans of irradiated beef were opened immediately or after G-months storage at ambient temperature. The beef was then slurried, and distillation was carried out in the usual manner 15,16). Nonirradiated beef slurries were distilled in exactly the same way as were periodic blank distillations of distilled water, to allow detection of contaminants or artifacts contributed by the distillation apparatus. In all cases, one condensate was collected at 0°C. (distillate) and another at — 78°C. (traps). 

Distillation apparatus, 31, 70 Doebner reaction, 31, 35 Drying methods, diethyl phthalate, 31,2 magnesium ethoxide, 31, 2 Dulcin, 31, 10... 

The distillation apparatus, commonly called a still, consists of a vessel for plant material and water, a condenser to cool and condense the vapour produced and a method of collection, or receiver. Material from the appropriate... 

The evaporation may be carried out in an ordinary distillation apparatus, but it is essential to stir the mixture to prevent bumping. It is advantageous from the point of view of speed and convenience to employ the method described below. 

Distillation is a veiy common method for purifying liquids. Atmospheric distillation (general distillation), vacuum distillation, and steam distillation are the three common methods of distillation. Atmospheric distillation takes place at atmospheric pressure, which means the distillation apparatus is open to the air. Vacuum distillation utilizes reduced pressure to distill a liquid at lower temperature. Vacuum distillation is commonly used to distill liquids, which tend to decompose at their atmospheric boiling points. Vacuum distillation is also used to conveniently distill liquids with relatively high boiling points at a much more efficient temperature. Steam distillation is similar to atmospheric distillation, but steam is used to promote volatility. Steam distillation only works on liquids or solids, which are volatile with steam. 

Procedure Into a standard distillation apparatus, alcohol still, or other means, place 1250 milliliters (42.2 fluid oz.) of vodka, and then distill the alcohol at 80 Celsius for about 4 hours. After 4 hours, remove the heat source, and then recover the alcohol that distilled over into the receiver flask or receiver container. Now, place this alcohol (which will be composed of about 90%+ ethyl alcohol), into a large seperatory funnel or equivalent, and then add in 50 grams (3.5 oz.) of pickling salt. Thereafter, vigorously shake the entire mixture for about 10 minutes. After 10 minutes, allow the mixture in your seperatory funnel or equivalent, to stand for about 30 minutes. Thereafter, drain-off the bottom water layer and excess salt, and thereafter, recover the upper alcohol layer. Now, place this recovered upper alcohol layer into a standard distillation apparatus, as illustrated in method 1 or similar, and then add in 500 milliliters (17 fluid oz.) of fresh battery acid. Thereafter, boil this mixture at 100 Celsius for about 6 to 8 hours, and allow the mixture to distill during this time. After 6 to 8 hours, remove the heat source, and then recover the diethyl ether from the receiver flask or receiver container. Then re-distill this diethyl ether using a standard fractional distillation apparatus or equivalent in the same manner as in method 1 (distill at 40 Celsius). Note the battery acid mixture left over, can be recycled, but it must be boiled to drive-off at least 1/3 of the total volume (to remove water). 

Procedure Into a suitable beaker or container, place 500 milliliters (17 fluid oz.) of 95% ethyl alcohol, and then place the beaker or container into an ice bath, and chill to about 5 to 10 Celsius. Thereafter, slowly add in, in very small portions, 40 grams (1.4 oz.) of metallic sodium over a period of about 1 hour. After the addition of the metallic sodium, stir the entire alcohol mixture for about 30 minutes, and then place it into a standard distillation apparatus (as similar to 1. Chloroform, method 1, step 3), and distill the ethyl... 

Procedure Place 194 grams (6.8 oz.) of 98% sulfuric acid into a beaker, and then place the beaker in an ice bath and cool to 0 Celsius. When the sulfuric acid reaches a temperature of 0 Celsius, slowly add in portions, 100 grams (3.5 oz.) of potassium nitrate or 84 grams (3 oz.) of sodium nitrate over a period of 1 hour while stirring the sulfuric acid and maintaining its temperature at 0 Celsius. After the addition of the potassium or sodium nitrate, slowly add over a period of one hour, 260 milliliters (8.8 fluid oz.) of cold tap water while continuously stirring the sulfuric acid mixture and maintaining its temperature at 0 Celsius (note a precipitate may form before or after the addition of the water. If this is happens, never mind it). Then remove the ice bath and then extract the acid mixture with seven 150-milliliter portions (seven 5.07 fluid oz. portions) of methylene chloride. Afterwards, combine all seven portions of methylene chloride (if not already done so), and then add 7 milliliters (0.23 fluid oz. or 1.4 tsp) of water to the methylene chloride. Then place the entire methylene chloride (two phase) mixture into a distillation apparatus (see the illustration in method 3 below), and carefully distill at 40 Celsius until no more methylene chloride is collected in the receiver flask. 

---