Basic extractions

Basic Extractants. Only long-chain quaternary ammonium salts, R3NCH3 X , ia which R represents Cg—0 2 groups and X nitrate or thiocyanate, are effectively used for REE separations (see Quaternary ammonium compounds). The extractant reacts with REE according to an anion-exchange reaction ... 

Phenols are about a million times more acidic than alcohols (Table 17.1). They are therefore soluble in dilute aqueous NaOH and can often be separated from a mixture simply by basic extraction into aqueous solution, followed by ceacidihcation. 

To a cooled (—110X) solution of the silylvinyl lithium (from the stannylethene (37 mmol) and n-BuLi (41 mmol)) in THF (100 ml) was added precooled crushed C02 (ca. 150 ml). The mixture was stirred at — 110 X for 0.5h, and then allowed to warm to ambient temperatiire overnight. The mixture was poured into ether (200 ml) and extracted thoroughly with aqueous NaOH (1m). The basic extracts were acidified with dilute HC1 at 0°C and extracted well with ether. The ethereal extracts were dried, concentrated, and the residue was distilled to give the title acid (32 mmol, 86%), b.p. 68-74 °C/0.5mmHg. 

Basic chrome sulfate, 6 543 Basic copper chromate, molecular formula, properties, and uses, 6 561t Basic detergents, 15 222 Basic (cationic) dyes, 9 217, 242-243 anthraquinone, 9 301 azo, 9 421 24 Basic dyestuffs, 9 224 Basic extractants, of rare-earth elements, 14 642... 

Figure 4.12. A basic extract of an organic soil is shown on the left a sample of the sodium salt of humic acid is seen on the right. 

Inorganic species in soil are generally extracted with either water or an acid solution typically containing hydrochloric acid. Various other components that aid either in the solubilization, extraction, or stabilization of extracted inorganics, such as chelates, are also often added during the extraction process. Basic extractions are not as commonly used as are acid extractions with a few notable exceptions. The use of ion exchange resins to extract ions from soil is well established. 

TEBA-Mn04 (0.31 g, 1 mmol) and KMn04 (1.58 g, 10 mmol) in AcOH (15 ml) are added to the (acetoxyaryl)alkane (5 mmol) in AcOH (5 ml) at 30°C. The mixture is stirred for 3 days and then poured into aqueous Na2S03 (2%, 100 ml). The aqueous solution is extracted with Et20 (4 x 60 ml) and the ethereal extracts are further extracted with aqueous NaHC03 (2 x 100 ml). The basic extracts are acidified with H2S04 (5M) to... 

GC-MS spectral analysis. Subsequent extraction of the basified aqueous phase removed another 14% of the aqueous 1 C which contained 10 products as determined by the TLC analysis using solvents (j) and (k). HMI, which accounted for 58.8% of the extract, was the major component of this extract as determined by TLC cochromatography in solvents (j) and (k). Five other unidentified products were still present in the aqueous phase (TLC solvent (h)) after neutral, acidic and basic extraction. 

A fractionation procedure has been established and widely applied to studies of humic materials [42-44]. The procedure begins with natural OM (i.e., humus) and uses an aqueous basic solution (e.g., 0.1-0.5 mol/1 NaOH and Na2C03) to solubilize a fraction of the OM. The basic extract is then acidified which causes a precipitate to form, i.e., humic acids (HA). The fraction, which remains in solution, is called fulvic acids (FA). Humin is the name given to the insoluble organic fraction that remains after extraction of humic and fulvic acids. At nearneutral pH (pH 5 - 8), which is characteristic of most natural water, the FA are the most water soluble of these three fractions. HA are somewhat less soluble, with their solubility increasing as the pH increases. Humin is insoluble at all pH values. 

Later, Chu and Bjeldanes (53) showed that the binding histamine to mucin could be inhibited in vitro by spermine, spermidine, putrescine, cadaverine, and a basic extract of tuna. The inhibition required relatively high amine concentrations, and the concentrated tuna extract exerted only a 23% inhibition of binding ( ). Each mole of intestinal mucin can bind 2.5 moles of histamine (53). 

T0659 Resources Conservation Company, Basic Extractive Sludge Treatment (BEST) T0715 Smith Technology Corporation, Low-Temperature Thermal Aeration (ETTA)... 

T0659 Resources Conservation Company, Basic Extractive Sludge Treatment (BEST)... 

T0656 Remtech Engineers, Bubble Lance Low-Profile Diffused Air Stripper T0659 Resources Conservation Company, Basic Extractive Sludge Treatment (BEST) T0671 Rohm and Haas Company, Ambersorb 563 Adsorbent T0674 Roy F. Weston, Inc., Low-Temperature Thermal Treatment (LT3)... 

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