Extraction bottom layer

Combine the chloroform extracts (bottom layers) and evaporate to get the amides. 

Extract the resulting suspension with four 2-mL portions of methylene chloride (calibrated Pasteur pipet). Remove the methylene chloride extract (bottom layer) using a Pasteur filter pipet, and place the combined fractions in a 25-mL Erlenmeyer flask. Dry the solution over granular anhydrous sodium sulfate (0.5 g). 

To the acid chloride, mechanically stirred and heated on the steam bath, is added 2.5 kg. (805 ml. 15.6 moles) of dry bromine as rapidly as it will react (Note 5). The addition requires about 12 hours. The contents of the flask are stirred and heated an additional 2 hours, transferred to a dropping funnel (Note 6), and added in a thin stream to 5 1. of absolute ethyl alcohol, which has previously been placed in a 12-1. flask provided with a stopper carrying an effleient reflux condenser, a separatory funnel, and a mechanical stirrer. The resulting vigorous reaction is controlled by external cooling. After the dibromoacid chloride has been added, the reaction mixture is allowed to stand at room temperature overnight and is then poured into 5 1. of cold water. The top alcoholic aqueous layer is decanted and extracted once with 8 1. of ether. The oily bottom layer is dissolved in the ether extract, washed first with 1 1. of a 2% sodium bisulfite solution, then with two 1-1. portions of 3% sodium carbonate solution, and finally with several portions of water. The ether solution is dried over 175 g. of potassium carbonate the solvent is distilled on the steam bath. The yield of residual ester (Note 7) amounts to 2260-2400 g. (91-97% of the theoretical amount). 

Drugs and metabolites can be extracted from cultures and urine by adding 2 drops of concentrated HCI to 1 ml of urine for a pH of 1-2. Extract with three 1-ml volumes of diethyl ether (top layer) or methylene chloride (bottom layer). Combine extractions and evaporate with clean, dry nitrogen. Adjust to a pH of 8-10 by adding 250 /zl of 60% KOH to 1 ml of urine. Extract... 

The decolonization of the yellow product (Note 11) is achieved by dissolving the product in an equal volume of carbon tetrachloride (ca. 12 ml.) and vigorously shaking the solution thus obtained with 1.5 ml. of a freshly prepared aqueous 35% sodium thiosulfate. The two layers are completely separated after 5 minutes. The colorless bottom layer is drawn off into a 50-ml. Erlenmeyer flask. The top layer is extracted three times with 1.5 ml. of carbon tetrachloride. The combined carbon tetrachloride solution is dried over 0.5 g. (Note 12) of anhydrous magnesium sulfate for 30 minutes. The solution is then filtered into a 50-ml. distilling flask, and the magnesium sulfate is washed several times with carbon tetrachloride (total 5 ml.). The solvent is removed, and the colorless product is distilled as described above, affording 14.7-15.8 g. (69-74% overall, based on hexanoic acid 88-92% for the decolonization step) of colorless 2-bromohexanoyl chloride, b.p. 45-47° (1.5 mm.), n22 d 1.4706 (Note 13), i 4 1.4017 (Notes 14 and 15). 

The tip current depends on the rate of the interfacial IT reaction, which can be extracted from the tip current vs. distance curves. One should notice that the interface between the top and the bottom layers is nonpolarizable, and the potential drop is determined by the ratio of concentrations of the common ion (i.e., M ) in two phases. Probing kinetics of IT at a nonpolarized ITIES under steady-state conditions should minimize resistive potential drop and double-layer charging effects, which greatly complicate vol-tammetric studies of IT kinetics. 

If only the top layer is being extracted or washed, it does not have to be removed from the funnel, ever. Just drain off the bottom layer, then add more fresh extraction or washing solvent. Ask your instructor about this. 

Following this procedure, the funnel is positioned in a padded ring in a ring stand and left undisturbed for a period of time to allow the two immiscible layers to once again separate. The purpose of the specific design of the separatory funnel is mostly to provide for easy separation of the two immiscible liquid layers after the extraction takes place. All one needs to do is remove the stopper, open the stopcock, allow the bottom layer to drain, and then close the stopcock when the interface between the two layers disappears from sight in the stopcock. The denser of the two liquids is the bottom layer and will be drained through the stopcock first. The entire process may need to be repeated several times, since the... 

NaHCOj (twice with 25 mL 3.6% NaHCOj), and the rinses transferred to the funnel. The funnel contents were shaken vigorously for 1 min and allowed to separate and the bottom layer was discarded. Three mL H3PO4 (15 mL 20% H3PO4) was carefully added to the separatory funnel and gently swirled until effervescence diminished. The acidified solutions were extracted three times with 20 mL DCM (15 mL) and each DCM extract dried through anhydrous Na2S04 in a 125 mL Erlemeyer flask (100 mL beaker). The DCM solution was carefully evaporated to dryness. 

Repeat the extraction with an additional 5.0 mL of dichloromethane. Combine the separated bottom layer with the dichloromethane layer obtained from step no. 7. 

The first step in extraction is to pour the reaction mixture, or place the food product, plant, ect., to be extracted, and the solvent into the seperatoiy funnel or appropriate container. If extracting a chemical reaction mixture a two-layer mixture will result. Which layer is what depends on the densities of the chemicals in the reaction mixture verses the density of the solvent. If the density of the solvent is greater then the chemicals in the reaction mixture, the solvent will be the bottom layer. If the opposite is true, the solvent will be the upper layer. For example, when a water solution is to be extracted with two portions of methylene chloride, the water solution and the first portion of methylene chloride are placed into the seperatoiy funnel (make sure the stopcock is closed). A two-layer mixture results. The methylene chloride will be the bottom layer because methylene chloride is denser then water. If extracting a food product, plant, seed, ect., the solvent and the material to be extracted are placed into an extraction apparatus, or suitable container or blender and then heated and/or blended for a specified amount of time. 

Note In some cases the reaction mixture will be very dark in appearance, and when extracted, forms another dark appearance with the solvent making the phase boundary between upper and bottom layers hard to see. If this happens, hold the seperatoiy funnel up to a light, or use a flashlight. 

Procedure Into a suitable steam distillation apparatus (fitted with a 250 milliliter addition funnel, or better), place 100 grams (3.5 oz.) of cloves (regular store bought cloves). Thereafter, add in 500 milliliters (17 fluid oz.) of water, and then add 250 milliliters (8.4 fluid oz.) of water to the addition funnel. This 250-milliliter addition funnel should contain about 200 milliliters of water at all times, and the water therein should be added to the cloves and water mixture periodically to keep the flasks water volume at around 500 milliliters all throughout the steam distillation process. Then heat the cloves and water mixture to 105 to 110 Celsius, and allow the mixture to be steam distilled. The process should take about 150 minutes, and thereafter, stop the steam distillation process, and then recover the oily distillate in the receiver flask. Then extract this oily distillate with three 50-millilter portions (three 1.7 fluid oz. portions) of methylene chloride, and after the extraction, combine both methylene chloride portions (if not already done so). Note after each extraction, the methylene chloride will be the bottom layer each time. After the extraction, the upper water layer can be discarded. Now, extract the combined methylene chloride portion with six 50-milliliter portions (six 1.7 fluid oz. portions) of a 5% potassium hydroxide solution. After the extraction, combine all aqueous alkaline portions (if not already done so), and then briefly wash this combined aqueous alkaline portion with one portion of 50 milliliters (1.7 fluid oz.) of methylene chloride. Note after the extraction and washing, the aqueous alkaline portion will be the upper layer each time. After the extraction and washing, the methylene chloride can be recycled if desired. Then place this combined aqueous alkaline portion into a large beaker, and then carefiilly add in, slowly, 250 to 300 milliliters (8.5 to 10.1 fluid oz.) of a 5% hydrochloric solution. Note more or less acid may or 20... 

After the addition of the reactants is complete, the reaction is allowed to stir for an additional 30 min while the solution warms to room temperature. The reaction mixture is then transferred to a separatory funnel. The viscous organic bottom layer is separated from the aqueous layer and is dissolved in 200 mL of ether. The reaction vessel is washed with 100 mL of ether, and this ether portion is used to extract further the aqueous layer. The ether layers are combined, dried over magnesium sulfate, and filtered, and the solvent is removed under reduced pressure. The viscous oil is allowed to crystallize in an ice bath (0°C). The crystals are collected on a Buchner funnel, washed with 500 mL of water, and dried in a vacuum desiccator at 0.5 mm for 48 hr. 80.8 g (93%) of white crystalline bis(2,2,2-trichloroethyl) hydrazodicarboxylate (mp 85-89°C) is obtained. This material is sufficiently pure for the next preparation. However, further purification can be achieved using an Abderhalden drying apparatus (refluxing 95% EtOH for 12 hr at 0.05 mm MgS04 desiccant). Material purified in this way melted at 96.5-97.5°C (Notes 4 and 5). 

Partition the concentrated extract against 40 mL of 20 percent (w/v) potassium hydroxide (KOH). Shake for two minutes. Remove and discard the base layer (bottom). Repeat the base washes until color is not visible in the bottom layer (perform base washes a maximum of four times). Strong base (KOH) is known to degrade certain PCDDs/PCDFs therefore, contact time should be minimized. 

To the 2-nitro-2-aza-propanol/methylene chloride mixture, prepared in step 1, add 112 grams of methylnitramine. Then add 600 milliliters of 98% sulfuric acid into a suitable flask, and then chill to -10 Celsius by means of an ice bath. Then gradually add the 2-nitro-2-aza-l-propanol/methylene chloride solution in portions to the 98% sulfuric acid while stirring the sulfuric acid and maintaining its temperature below 0 Celsius. After the addition, add the entire reaction mixture into 2000 milliliters of cold water. Then decant the upper methylene chloride layer (keep for later), and then extract the bottom water layer with six, 100-milliliter portions of methylene chloride. Afterwards, combine all the methylene chloride layers (if not already done so), and include the upper methylene chloride layer decanted earlier. Then wash the methylene chloride fraction with two 300 milliliters portions of cold water (in this washing, the methylene chloride layer will be the bottom layer both times). After the 138... 

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