Extraction transferability

The problem with a simple extraction is that the separation only occurs in one direction. In a liquid-liquid extraction, for example, we extract a solute from its initial phase into the extracting phase. Consider, again, the separation of an analyte and a matrix interferent with distribution ratios of 5 and 0.5, respectively. A single liquid-liquid extraction transfers 83% of the analyte and 33% of the interferent to the extracting phase (Figure 12.1). If the concentrations of A and I in the sample were identical, then their concentration ratio in the extracting phase after one extraction is... 

Extraction Transfer of materials from plastics to liquids with which they are in contact. 

Extraction. Transfer 5 g sieved ( 2 mm) air-dried soil to a 100-ml glass beaker, add 20 ml M ammonium ethanoate, stir and let stand overnight. Transfer the contents to a filter funnel fitted with a 125 mm Whatman No. 44 filter paper and held in a 250 ml volumetric (graduated) flask. Wash the beaker with ammonium ethanoate reagent from a wash (squeeze) bottle to remove all the sample, then add successive 25 ml volumes of reagent to leach the soil in the funnel, allowing it to drain between additions. With the collected leachate volume approaching 250 ml, remove the funnel to a rack or... 

Procedure (extraction). Transfer 5 ml (scoop filled and struck off level without tapping) of air-dry soil, sieved to 2 mm into a bottle (e.g. wide-mouth, square HDPE). Add 100 ml of sodium bicarbonate reagent, pH 8.50, cap the bottle and shake on a reciprocating shaker, at approximately 275 strokes of 25 mm length per minute, for 30 min at 20°C. Filter a portion immediately through a Whatman No. 2 filter paper, rejecting the first few millilitres of filtrate. Carry out a blank determination. 

Procedure (extraction). Transfer 2.5 g air-dry soil, 2 mm mesh size, into a 250 ml polypropylene screw-cap centrifuge bottle/tube and add 100 ml acetic acid - 8-hydroxyquinoline reagent. Cap the tube and shake overnight (17 h) on a reciprocating shaker, at approximately 275 strokes of 25 mm length per minute at a constant temperature (20°C). Centrifuge for 15 min at 2800 rpm and remove an aliquot for the determination of acid extractable inorganic phosphorus (a). 

The Croy V series belt-driven dual extraction pump can extract from 5 to 30/gal min of liquid, and uses a 75 actual cubic feet per minute groundwater/vapor extraction transfer pump. The unit has a purchase price of 13,000 and can be rented for 1300 per month (D17804V, p. 11). 

The quantity (y — y) is the over-all driving force expressed in terms of extract compositions, as shown in the figure. The over-all number of extract transfer units NtoE for the extraction is then defined by integration of Eq. (9), assuming KEa remains constant ... 

Hioe Height of an over-all extract transfer unit, ft. 

NtoB Number of over-all extract transfer units, dimensionless... 

The stirred cell of Davies (11) was used to investigate the possible interfacial mechanism of extraction. Transfer of the complex Hs PbSCSN Hs from the aqueous to the organic phase was studied as a function of the stirring rate in the aqueous phase. 

Figure 10.1 Analysis of racemic 2,5-dimethyl-4-hydroxy-3[2H]-furanone (1) obtained from a strawberry tea, flavoured with the synthetic racemate of 1 (natural component), using an MDGC procedure (a) dichloromethane extract of the flavoured strawberry tea, analysed on a Carbowax 20M pre-column (60 m, 0.32 mm i.d., 0.25 pan film thickness carrier gas H2, 1.95 bar 170 °C isothermal) (b) chirospecific analysis of (1) from the strawberry tea extract, transferred for stereoanalysis by using a permethylated /1-cyclodextrin column (47 m X 0.23 mm i.d. carrier gas H2, 1.70 bar 110°C isothermal). Reprinted from Journal of High Resolution Chromatography, 13, A. Mosandl et al., Stereoisomeric flavor compounds. XLIV enantioselective analysis of some important flavor molecules , pp. 660-662, 1990, with permission from Wiley-VCH.

Vamidothion and its oxidation metabolites Apples Acetone extraction, transfer to methylene chloride Capillary GC-MS with secondary ion monitoring [121]... 

Thus in liquid-liquid extraction there are two immiscible liquids of which at least one single component is soluble in both the feed and the contacting solvent. This component—the solute—transfers from one liquid phase to the other. This extraction transfer process falls into three categories ... 

Water-Soluble Annatto Extracts Transfer 2 mL or 2 g of sample into a 50-mL separatory funnel, and add sufficient 2 N sulfuric acid to make the solution acidic to pH test paper (pH 1 to 2). Dissolve the red precipitate of norbixin by mixing the solution with 50 mL of toluene. Discard the water layer, and wash the toluene phase with water until it no longer gives an acid reaction. Remove any undissolved norbixin by centrifugation or filtration, and dry the solution over anhydrous sodium sulfate. Transfer 3 to 5 mL of the dry solution to the top of an alumina column prepared as described above. Elute the column with toluene, three 10-mL volumes of dry acetone, and 5 mL of Carr-Price Reagent (see Solutions and Indicators) added to the top of the column. The orange-red band of norbixin immediately turns blue-green. 

Oil-Soluble Annatto Extracts Transfer a sample, accurately weighed, into a solution of 1% glacial acetic acid in acetone, and dilute to a suitable volume (absorbance of 0.5 to 1.0). Filter the sample to clarify if necessary. Measure the absorbance at 454 nm, and calculate the color intensity by the formula... 

Water Extractables Transfer 5.00 g of sample into a 250-mL flask provided with a reflux condenser and a Bunsen valve. Add 100 mL of water and several glass beads, and reflux for 1 h. Cool slightly, and filter through Whatman No. 2, or equivalent, filter paper, discarding the first 10 mL of filtrate. Cool the subsequent filtrate to room temperature, and pipet 25.0 mL into a tared crystallization dish. 

Identification Place about 150 mg of melted sample into a 16- x 125-mm tube equipped with a screw cap having a Teflon liner, and add 4 mL of absolute methanol, 4 drops of a 25% sodium methoxide solution in absolute methanol, and a boiling chip. Cap the tube, reflux for 15 min, and cool to room temperature. Extract as follows Add 8 drops of a 15% potassium acid sulfate solution, 4 mL of water, and 4 mL of n-hexane cap the tube shake for 1 min and centrifuge for 30 to 60 s. Decant and discard the M-hexane layer, and repeat the extraction with three additional 4-mL portions of M-hexane, discarding each extract. Transfer the aqueous alcoholic phase from the tube into a 50-mL round-bottom, glass-stoppered flask place the flask in a water bath at 50° to 55° and evaporate to near dryness (about 0.5 mL of residue) in a rotary film evaporator under full water aspirator vacuum. 

Sample Solution Transfer about 150 mg of sample, accurately weighed, into a saponification flask, add 50 mL of 4% alcoholic potassium hydroxide solution, and reflux for 1 h. Acidify the reaction mixture with hydrochloric acid to a pH of 2.8 to 3.2, transfer into a 400-mL beaker, and evaporate to dryness on a steam bath. Quantitatively transfer the contents of the beaker into a separator, using no more than 50 mL of water, and then extract with three 50-mL portions of petroleum ether (b.p. 30° to 60°), discarding the extracts. Transfer the water layer to a 100-mL volumetric flask, dilute to volume with water, and mix. 

Alkaline Ether Extract Transfer 5 g of the colorant to a beaker, and dissolve in 150 mL of water. Add 2 mL of 2.5 (VNaOH solution, transfer the solution into the extractor and dilute to approximately 200 mL with water. Add 200 mL of ether to the distillation flask, and extract for 2 h with a reflux rate of about 15 mL/min. Set the extracted colorant solution aside. Transfer the ether extract into a separatory funnel, and wash with two 25-mL portions of 0.1 A NaOH followed by two 25-mL portions of water. Reduce the volume of the ether extract to about 5 mL by distillation (in portions) from a tared flask containing a small piece of clean copper coil. 

Figure 48 shows the usefulness of solid electrolyte cyclic voltammetry (SECV) for extracting transfer coefficients. The peak potentials are plotted against the logarithm of the sweep rates. The value can be obtained from the slope of the linear regression curve. It is calculated to be 0.63, which is close to the value, 0.59, obtained from the steady-state potentiostatic study. Similarly, based on the equation for anodic peaks. 

M DOP, the mixing time being 10 minutes. Under these conditions the Eu/Am separation factor is about 30, and triple extraction transfers 97 europium into the organic phase. 90% Am stay in the aqueous phase, where the content of Eu is no higher than 3%. Americium can then be quantitatively extracted by 0.04 M DOP toluene solution, the phases being mixed for 45 minutes. 

Starting with 1.00 g. (0.013 mole) of selenium and 5.00 g. (0.023 mole) of antimony pentafluoride, the procedure is at first identical with that for Se8(Sb2F11)2. However, when the room-temperature reaction is complete, the whole apparatus is placed in a 60° oven for 12 hours. A bright yellow solid and a yellow solution are obtained. As a safety precaution the oven is switched off and the apparatus is allowed to cool to room temperature before being removed. Three room-temperature extractions transfer all the Se4(Sb2F11)2 into flask B. After sulfur dioxide has been distilled, the product is removed from B and pumped to constant weight. The yield is quantitative. Anal. Calcd. for Se4Sb4F22 Se, 25.87 Sb, 39.89 F, 34.24. Found Se, 27.04 Sb, 38.54 F, 33.9. 

T=EXTRACT TRANSFER VALVE D EXTRACT DRAWOFF VALVE F= FEE0 WATER VALVE... 

The requirements for correct operation of SFE-SFC technique are (i) the extraction chamber volume must be appropriate for the sample size in SFC (ii) the SF pressure drop (mobile phase) during the extract transfer to the chromatograph must be minimum, and (iii) the chromatograph must be pressurized and equilibrated to the required pressure before the injection of extracts. 

CO2 + 5% MeOH, 0.92 g/ml, 365 atm, 45°C, 20 min static, 30 min dynamic, 2 ml/min Direction of fluid flow up extraction vessel orientation vertical SFE extracts collected in (i) Isco 15 ml methylene chloride, (ii) HP octadecyl-bonded silica trap and rinsed off the trap with 3 X 1.8 ml portions of methylene chloride extracts transferred to a 60 ml reparatory funnel and concentrated by nitrogen to a final volume of approximately 0.5 ml derivatization step extract treated with pentylmagnesium bromide (PMB) to convert the ionic organotin compounds into their neutral derivatives Extraction parameters studied... 

The height of the extractor will be determined fromh = (NTU)(HTU). Simplified equations for the number of extraction transfer units for the dispersed phase, Ooe-d continuous phase, Ooe-cj defined in the same way as noL in Eq. Q6-26i. are... 

Add 23 ml n-pentane to the water sample prepared in the above manner. Then seal the flask and stir the mixture on a magnetic stirrer at approx. 1100 rpm for 10 minutes. After the phases have separated, the extract is sucked off and transferred to a 30 ml volumetric flask. A further 23 ml diisopropylether is now added to the water sample remaining in the 1 litre volumetric flask. The mixture is then stirred for a further 10 minutes and the extract transferred as above to the 30 ml volumetric flask. After making up to the mark, add between 1 and 4 g... 

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