Extraction yield

U02(C02) 3. The pregnant solution is concentrated and purified by ion exchange or solvent extraction, yielding a stripping solution of ca 50 kg/m U Og. Uranium is then precipitated chemically. Pure U Og is obtained by calcination (see Uraniumand URANIUM COMPOUNDS). 

Concentration of mash, malt water Extract yield, % Fermentable extract, %... 

Wort separation and beer filtration are two common bottlenecks ia the brewiag process. Poor lauteriag aot only causes a loss ia productioa capacity, but can also lead to losses ia extract yield. Furthermore, a slow lauteriag aegatively affects the quaHty of the wort, which may give beer filtratioa problems and problems with the flavor and stabiHty of the beer. 

The main components of Salvia mirzayanii were Linalool, Linalyl acetate, a-Tei pinyl acetate, 5-Cadinene, Spathulenol, Cubenol and a-Cadinol. The extraction yield, based on hydrodistillatin was 2.2% (v/w), and based on the SFE varied in the range of 0.65-10.59% (v/w) under different conditions. 

A fifth extraction yields no further product. The residue insoluble in hexane was found by the submitters to consist of 1.3-1.9 g. of a mixture of equal parts of di-a-naphthylthiourea and a-naphthylthiourea, m.p. 178-181. ... 

Several methods ean be employed to eonvert eoal into liquids, with or without the addition of a solvent or vehiele. Those methods which rely on simple pyrolysis or carbonization produce some liquids, but the mam produet is eoke or char Extraction yields can be dramatically increased by heating the coal over 350°C in heavy solvents sueh as anthraeene or eoal-tar oils, sometimes with applied hydrogen pressure, or the addition of a eatalyst Solvent eomponents whieh are espeeially benefieial to the dissolution and stability of the produets eontain saturated aromatic structures, for example, as found in 1,2,3,4 tctrahydronaphthalene Ilydroaromatie eompounds are known to transfer hydrogen atoms to the coal molecules and, thus, prevent polymerization... 

The combined aqueous washes are acidified with dilute hydrochloric acid and extracted with ethyl acetate. Evaporation of this extract yields 86 mg of 3a-hydroxy-ll-oxo-5j -etianic acid, mp 291-293° (dec.). 

Schiittung, /. pouring, etc. (see schUtten) blasting (Brewing) extract-yielding materials. 

In an initial step, dibenzo[a,d] cyclohepten-5-one is reacted with the Grignard reagent of 3-di-methylaminopropyl chloride and hydrolyzed to give 5-(3-dimethylaminopropyl)-dibenzo[a,d] -[1,4] cycloheptatriene-5-ol. Then 13 g of that material, 40 ml of hydrochloric acid, and 135 ml of glacial acetic acid is refluxed for 314 hours. The solution is then evaporated to dryness in vacuo and added to ice water which is then rendered basic by addition of ammonium hydroxide solution. Extraction of the basic solution with chloroform and removal of the solvent from the dried chloroform extracts yields the crude product which when distilled in vacuo yields essentially pure 5-(3-dimethylaminopropylidene)-dibenzo[a/f ] [ 1,4] cycloheptatriene, BP 173°C to 177°C at 1.0 mm. 

Distillation of the extract yields 28.5 grams of a very viscous yellow liquid with a BPo.95-i.o9 millibar 38° to 202°C. The yield is 70.5% (theoretical quantity = 40,5 grams). 

Trainor (1979) modified the above method (1) In the initial extraction, luciferin was extracted with 50 mM acetate buffer (pH 4.75) at 95°C, instead of boiling 20% methanol, to increase the extraction yield. (2) In the DEAE-cellulose chromatography, the column, on which the luciferin sample had been adsorbed, was washed with the following solvents before the elution of luciferin water, lOmM HC1 in methanol, methanol, and NaCl-saturated methanol. (3) To eliminate salts in purified luciferin, the solution was evaporated to dryness, and the luciferin in the residue was extracted with... 

A recent study on wheat bran GAX [34] revealed the presence of lowly and highly substituted GAX fractions, which greatly differ in the amount and type of substitution by the Ara/ imits, but not in the content of the glucuronic acid, half of which occurs as the 4-0-methyl ether. Feruloylated GAX fractions were isolated from wheat bran by cold water, steam and dilute alkah [35]. The yields of water and steam-extracted material were 1.5 and 20-31%, respectively, however, they contained 1.5% and 19-28%, respectively, of GAX. The alkah extraction yielded 10-30% material containing more than 90% of the GAX with moderate FA content. 

Marigold petals are rich sources of xanthophyUs, mainly lutein esters. To increase the coloring power, chemical extraction of the colorant from flower meal is performed or a new enzymatic procedure is applied. It was shown that treatment with cellulases or mixed saprophyte microorganisms or solid state fermentation improved the xanthophyll extraction yield. ... 

The influence of enzyme maceration using pectinolytic enzyme preparations (Pectofruit and Pectofruit Press) on anthocyanin extraction at 43°C from two variants of black currant berries was studied. Enzymes accelerated the extraction yield the yield of anthocyanin extraction was similar for both enzymes and the duration did not influence the total content of released pigments. 

On the other hand, quantitative extraction requires complete and exhaustive extraction and no material can be lost. To assure complete extraction when a food is analyzed for the first time in a laboratory, it is useful to carry out two or three extractions, pool the solvents, and keep separate the next extracts to verify the presence of carotenoids. Usually four to six extractions are enough to remove the carotenoids completely from a sample. The extraction can be carried out in a blender, vortex, or with a mortar and pestle. Accelerated solvent extraction (ASE), an important extraction technique in residue analysis, currently attracts interest due to its short duration, low level of solvent use, and high extraction yield. The average recoveries for all carotenoids with the exception of norbixin ranged from 88.7 to 103.3% using manual extraction and from 91.0 to 99.6% by ASE (70 bar and temperature of 40°C) both extractions were carried out with a mixture of MeOH, EtOAc, and petroleum ether (1 1 1). ... 

When Winter senescent plant material was harvested and extracted, yields of OFAs were greatly reduced. OFAs from the four ponds were extracted easily from 20-50 liters of pond water by passing the water through a tube filled with ODS silica. These ponds produced between 1 and 1.5 ppm of OFAs after elution with methyl formate. The origin of I, Ila and lib in these ponds is uncertain at this time. 

Table 3.39 Extraction yield (in pig g 1) of Irganox 1076 from LLDPE...

Freitag and John [96] studied rapid separation of stabilisers from plastics. Fairly quantitative extraction (>90% of the expected content) of stabilisers from a powdered polymer was achieved by MAE within 3 to 6 min, as compared to 16 h of Soxhlet extraction for the same recovery. MAE and Soxhlet extraction have also been compared in the analysis of cyclic trimer in PET [113]. On the other hand, Ganzler et al. [128] compared the extraction yields for various types of compounds from nonpolymeric matrices for microwave irradiation with those obtained by the traditional Soxhlet or shake-flask extraction methods. Microwave extraction was more effective than the conventional methods, in particular in the case of polar compounds. As expected, the efficiency of the former is high especially when the extraction solvents contain water. With the high dipole moment of water, microwave heating is more... 

Hinman et al. [492] have compared SFE and ASE in the extraction of antioxidants from LDPE. Comparable extraction yields were obtained with both techniques. However, sample clean-up was necessary after ASE , while with SFE the extract could be analysed directly without any post-extraction clean-up. Supercritical fluid extraction of 15 polymer additives (AOs, UVAs, process lubricants, flame retardants and antistatic agents) from eight PS formulations was compared to dissolu-tion/precipitation extractions [557], Additive recoveries were comparable. Numerous additional comparisons can be found under the specific headings of the extraction techniques (Sections 3.3 and 3.4). 

HPLC methods of determining the amounts of different additives in polymeric materials are preceded by an extraction process or dissolution of the polymer matrix. Although extraction-HPLC is often observed to be superior to the traditional spectroscopic techniques (UV and IR) in analysing additives, it is frequently difficult to obtain reproducible results in view of the variability of the extraction yield. On the other hand, it is equally difficult to obtain quantitative data in the dissolution/reprecipitation-HPLC method because of entrapment of analytes in the polymer precipitate and the potential for high absorption of the additives on the polymer surface. 

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