Sodium Carbonate Extractant

4 Determination of Acryionitriie Monomer in 5% Sodium Carbonate Extractant 

The results in Table 11.1 (samples C and D) show that above 80% of the added amount of acrylonitrile was recovered in the methanol distillate when the azeotropic-distillation procedure was applied to 5% sodium carbonate extractants containing up to 72.4 ppm of acrylonitrile monomer. The recoveries of acrylonitrile in these experiments are lower than those obtained for the distilled water and 6% hydrochloric acid extractants. This may be due to an increased amount of hydrolysis of acrylonitrile 

Extractants after Azeotropic Distillation with Methanol 

Sample Composition of synthetic test solution used for azeotropic distillation Volume of test solution used for azeotropic distillation, ml Acrylonitrile added, pg (X) Weight of acrylonitrile in test solution, pg Recovery of acrylonitrile in first two fractions obtained by azeotropic distillation Y X 100/X, % w/v 

5 Determination of Acryionitriie in Light Liquid-Paraffin Extractant 

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To a mixture of 10 g. of the compound and 3-5 ml. of 33 per cent, sodium hydroxide solution in a test-tube, add 2-5 ml. of 50 per cent, chloroacetic acid solution. If necessary, add a little water to dissolve the sodium salt of the phenol. Stopper the test-tube loosely and heat on agently-boiling water bath for an hour. After cooling, dilute with 10 ml. of water, acidify to Congo red with dilute hydrochloric acid, and extract with 30 ml. of ether. Wash the ethereal extract with 10 ml, of water, and extract the aryloxyacetic acid b shaking with 25 ml. of 5 per cent, sodium carbonate solution. Acidify the sodium carbonate extract (to Congo red) with dilute hydrochloric acid, collect the aryloxyacetic acid which separates, and recrystallise it from hot water. 

A suspension of 17a,21-dihydroxypregna-4,9(ll)-diene-3,20-dione 21-acetate (0.77 g) and iV-bromoacetamide (0.3 g) in anhydrous methylene dichloride (40 ml) is added over 2-3 min with stirring to a mixture of anhydrous hydrogen fluoride (10.19 g), and anhydrous tetrahydrofuran (18 g) in a polyethylene bottle at —80° (acetone-dry ice). After 1 hr at —80° the reaction mixture is kept for a further 1 hr at 0° and then added cautiously to an excess of an ice-cold solution of sodium carbonate. Extraction with methylene dichloride and crystallization from acetone-hexane furnish 9a-bromo-ll -fluoro-17a,21-dihydroxypregn-4-ene-3,20-dione 21-acetate (0.69 g), mp 205-208°, raised by several crystallizations from acetone-hexane to 215-217° [aju 142° (CHCI3) max 240-242 mju (e 15,500). 

Step 1 1-(p-Chlorophenyl)-3-Ethoxy-1 H-lsoindole - Crystalline triethyloxonium boron-tetrafluoride (21 g) (prepared from 23 g of borontrifluoride etherate and 11 g of epichlorohydrin) is dissolved in 100 ml of absolute methylenechloride. 3-(p-Chlorophenyl) phthalimidine (21 g) is added and the reaction mixture is stirred overnight at room temperature. The resulting solution is poured onto 50 ml of saturated Sodium carbonate, extracted with 500 ml of ether and dried. Upon evaporation of the solvent there is obtained crude material which is recrystallized from methylene chloride/hexane (1 1) to yield l-(p-chlorophenyl)-3-ethoxy-1 H-isoindole MP 102° to 103°C. 

An additional 5-8 g. of slightly colored material can be secured by neutralizing the aqueous solution with 200 g. of sodium carbonate, extracting with 500 ml. of ether, and distilling. The total yield of distilled product then amounts to 125-130 g. (95-97%). 

The filtrate, ca. 4 1. in volume, is extracted with three 1.5-1. portions of ether (Note 4), and the sulfuric acid mother liquors are discarded. The ether extracts are combined and used to dissolve the solid mixture of acid and ester. If necessary, more ether can be added to assist in dissolving the solid. The ether solution is washed with 50 ml. of cold water and extracted with approximately ten 100-ml. portions of saturated sodium carbonate solution until all the isodehydroacetic acid has been removed (Note 5). The combined sodium carbonate extracts are acidified with an excess of concentrated hydrochloric acid, and the finely divided acid which precipitates is redissolved by heating to the boiling point. The hot solution is filtered with the aid of suction and is cooled in an ice bath the solid is collected on a filter. The crude isodehydroacetic acid is dissolved in 400 ml. of hot water, and this solution treated with decolorizing carbon, filtered, and cooled slowly to effect crystallization. The yield of isodehydroacetic acid is 91-115 g. (22-27%) m.p. 154-155°. 

Phenyl -tolyl selenide in aqueous suspension is boiled with potassium permanganate for several hours. The manganese mud is dissolved and the 4-carboxydiphenyl selenoxide precipitated by passing in sulphur dioxide. After filtration the precipitate is macerated with dilute sodium carbonate solution, the products of oxidation being separated in this manner into phenyl p-tolyl selenoxide and 4-carboxydiphenyl selenoxide. Addition of dilute sulphuric acid to the sodium carbonate extract causes the separation of 4-carboxydiphenyl selenoxide, which is crystallised from alcohol. The product is a microcrystalline powder, melting with decomposition at 253° to 255° C. Attempts to resolve it into optically active forms have failed the l-menthylamine salt melts at 220° to 222° C. with decomposition, and the d-a-phenyl-ethylamine salt forms feathery needles, M.pt. 194° to 195° C. with decomposition.3... 

Methylnitramine is conveniently prepared3 by nitrating methylurethane with absolute nitric acid, drowning in water, neutralizing with sodium carbonate, extracting with ether, and... 

The sodium carbonate extract contains only a few milligrams of the enedione. 

Heber et al. [422] determined the herbicides imazethapyr and imazapyr on a 0.1 M sodium carbonate extract of soil. Clean-up was by partitioning with methylene chloride, and final analysis was by high-performance liquid chromatography with UV detection at 260 nm. Lagona et al. [423] and Krynitsky... 

A 300 g portion of fermented material was placed in 500 ml of deionized water and slurried. The slurry was then heated for about 15 minutes at 75°C, 300 g of filter aid were then added and the material was filtered. The solid filtered material containing the anabolic substance was then air dried, and 333 g of the dried cake were then extracted with 500 ml of ethanol. This procedure was repeated three more times. The ethanol extract was then dried under vacuum to give 6.84 g of solid material. This solid material was then dissolved in 20 ml of chloroform and extracted with 30 ml of an aqueous solution containing 5% by weight of sodium carbonate having an adjusted pH of about 11.2. The extraction process was repeated seven more times. The pH of the sodium carbonate extract was then adjusted to 6.2 with hydrochloric acid, to yield an anabolic substance containing precipitate. The precipitate and the aqueous sodium carbonate extract were then each in turn extracted with... 

The ether extracts, after washing with salt solution, are extracted with one 100-ml. and two 50-ml. portions of 5% sodium carbonate solution. It is important that the ether solution be free of any mineral acid before the carbonate extractions are made. The residual ether solution, after being washed with 10% sodium chloride solution, is dried over sodium sulfate. The ether is removed by distillation, and the residue is distilled under reduced pressure. The yield of 7-M-propylbutyrolactone is 14.5 g. (36%), b.p. 78-80°/2 mm. The combined sodium carbonate extracts are acidified to Congo red paper with concentrated hydrochloric acid and then thoroughly extracted with one 100-ml. and two 50-ml. portions of ether. The combined ether extracts are washed with 10% sodium chloride solution and dried and, after the ether is removed by distillation, the residue is distilled under reduced pressure. The yield of /J-(tetrahydrofuryl)-propionic acid is 15.9 g. (36%), b.p. 118-120°/2 mm. 

The characteristic colours and solubilities of many metallic sulphides have already been discussed in connection with the reactions of the cations in Chapter III. The sulphides of iron, manganese, zinc, and the alkali metals are decomposed by dilute hydrochloric acid with the evolution of hydrogen sulphide those of lead, cadmium, nickel, cobalt, antimony, and tin(IV) require concentrated hydrochloric acid for decomposition others, such as mercury(II) sulphide, are insoluble in concentrated hydrochloric acid, but dissolve in aqua regia with the separation of sulphur. The presence of sulphide in insoluble sulphides may be detected by reduction with nascent hydrogen (derived from zinc or tin and hydrochloric acid) to the metal and hydrogen sulphide, the latter being identified with lead acetate paper (see reaction 1 below). An alternative method is to fuse the sulphide with anhydrous sodium carbonate, extract the mass with water, and to treat the filtered solution with freshly prepared sodium nitroprusside solution, when a purple colour will be obtained the sodium carbonate solution may also be treated with lead nitrate solution when black lead sulphide is precipitated. 

Bromides and iodides interfere because of the liberated halogen the test is not trustworthy in the presence of chromates, sulphites, thiosulphates, iodates, cyanides, thiocyanates, hexacyanoferrate(II) and (III) ions. All of these anions may be removed by adding excess of nitrate-free Ag2S04 to an aqueous solution (or sodium carbonate extract), shaking vigorously for 3-4 minutes, and filtering the insoluble silver salts, etc. 

Unless the sample is readily soluble in water, the solution is unsuitable for testing for anions, as during dissolution in acids some of these might decompose. For the test for anions we can use either the aqueous solution, or, if the sample is not soluble in water, sodium carbonate extract should be prepared either from the whole of the sample, or the sample should first be extracted with hot water and the residue treated with sodium carbonate. This procedure is described in detail in Section V.18. 

If ammonium is present, ammonia will be evolved (indicated by the smell above the solution) continue boiling until ammonia is completely expelled, otherwise those metals which form ammonia complexes may pass into the sodium carbonate extract. 

Cleaning Up To the filtrate add sodium bisulfite (until a negative test with starch-iodide paper is observed) to destroy any remaining perbromide, neutralize with sodium carbonate, extract the pyridine released with ether, which goes in the organic solvents container. The aqueous layer can then be diluted with water and flushed down the drain. 

Kiho T, Tabata H, Ukai S, Hara C. A minor, protein-containing galactomannan from a sodium carbonate extract of Cordyceps sinensis. Carbohydr Res 156 189-198, 1986. 

Sample preparation Make serum alkaline with 10% sodium carbonate, extract with diisopropyl ether (Caution Diisopropyl ether readily forms explosive peroxides ). Remove the organic layer and extract it with 10 mM HCl, inject an aliquot of the aqueous layer. 

Sample preparation Plasma or saliva. 1 mL Plasma or saliva + 200 ng IS -I- 250 p,L saturated sodium carbonate + 500 jtL saturated solution of sodium sulfate in EtOH, extract into 5 mL dichloromethane. Evaporate the organic layer and dissolve the residue in 200 xL 100 mM HCl mobile phase 1 1, iiyect an aliquot. Urine. 1 mL Urine -t- 2000 ng IS + 1 mL saturated sodium carbonate, extract into 5 mL dichloromethane. Evaporate the organic layer and dissolve the residue in 200 aL mobile phase, iiyect an aliquot. 

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