Sulphate, extraction

Calculation. There were 20 ml soil in 50 ml of extractant, therefore sample concentration values from the standard graph should be multiplied by 2.5, the results being expressed as mg b nitrate-N calcium sulphate extractable in air-dry soil. Include any extra dilution factors, and, if required, convert to oven-dry soil using the appropriate factor, as in Method 5.2, Calculation (2). 

Phosphorus intermediate standard solution, 100 pg mh - pipette 50 ml of the phosphorus stock standard solution, 1 mg mM, into a 500-ml volumetric flask, make up to the mark with sodium sulphate extractant and mix. Add 1 drop of toluene to the solution. 

Calculation. The 2-ml scoop of soil was extracted via resin into 50 ml sodium sulphate extractant therefore the concentration must be multiplied by 25 to give the pg P ml in soil by resin extraction. Hislop and Cooke (1968) classified the soils with respect to mg P h air-dry soil as follows ... 

In 1862, E. C. C. Stanford proposed the carbonization of the drift-weed in closed retorts so as to recover tar and ammoniacal liquor in suitable condensers. This modification did not flourish because of the subsequent difficulties in extracting soluble iodides from the charcoal. V. Vincent (1916) claims that soln. containing aluminium sulphate extract the alkali iodides from seaweed leaving behind the organic matter which prevents the direct precipitation of iodine or iodides. The alkali iodide soln. is treated with copper sulphate for cuprous iodide, or by soln. of sulphites for iodine. M. Paraf and J. A. Wanklyn proposed to heat the drift-weed first with alkali hydroxide so as to form oxalic and acetic acids, which could be crystallized from the lixivium. The economical treatment of seaweed for iodine has been discussed by A. Puge. 

The analysis of ferrotantalum alloys and of tantalum steels also involves the conversion of the tantalum present into the pentoxide. The material is dissolved in hydrofluoric add and nitric acid, evaporated to dryness, and the residue fused with potassium hydrogen sulphate extraction with dilute hydrochloric acid and hydrolysis yield a predpitate of hydrated tantalic pentoxide, the iron remaining in solution.7... 

Fig. 1. Protein patterns of the subnuclear fractions. 12% polyacrylamide gel electrophoresis in 0.1% SDS. Coomassie blue staining. A Nuclei B DNase-released C RNase-released D ammonium sulphate extract nuclear matrix...

At the time that this plant was operating, the extreme toxicity of beryllium compounds was not fuUy appreciated. Eight deaths were caused at the Degussa Company which could be directly attributed to beryllium compounds, two of them at the sulphate extraction stage. s... 

Schwenzfeier, C. W. The sulphate extraction of beryllium from beryl. The Metal Beryllium, p. 71. The American Society for Metals (1955). 

Extraction of ethoxylated alcohol (by deionisation) gives ether sulphate Fatty acid by petroleum ether extraction and alkali titration (lower ethoxylates also extracted) gives glyceride sulphate Extraction of fatty amine and acid titration (lower ethoxylates also extracted) gives sulphosuccinamate... 

This reaction is also used on a large scale, to obtain iodine from seaweed. The ash from burnt seaweed ( kelp ) is extracted with water, concentrated, and the salts other than iodides (sulphates and chlorides) crystallise out. The more soluble iodides remain and the liquor is mixed with sulphuric acid and manganese dioxide added the evolved iodine distils off and is condensed. 

Ammonium cyanate, because of its instability in solution, is usually prepared (NHJaSO, + 2KCNO 2NH4CNO + KjSO by mixing aqueous solutions of ammonium sulphate and potassium cyanate. Complete evaporation then gives a mixture of potassium sulphate and urea, from which the urea may be extracted w ith hot absolute ethanol, in which potassium sulphate is insoluble. 

In view of the small volume of nitromethane to be manipulated, the crude nitromethane may be extracted from the aqueous distillate with ether (30-40 ml.). Dry the ethereal extract over sodium sulphate, filter through a fluted filter-paper, and then distil off the ether on a water-bath with the usual precautions (Fig. 64, p. 163 Fig, 23(E), p. 45) finally distil the residual nitromethane. 

Add cautiously 15 ml. of concentrated sulphuric acid to 50 ml. of water in a 100 ml. distilling-flask, and then add 10 g. of pinacol hydrate. Distil the solution slowly. When about 40 ml. of distillate (consisting of pinacolone and water) have been collected, and no more pinacolone comes over, extract the distillate with ether. Dry the extract over sodium sulphate. Distil the dry filtered extract carefully, with the normal precautions for ether distillation (p. 164). When the ether has been removed, continue the distillation slowly, rejecting any fraction coming over below 100 . Collect the pinacolone, b.p. 106 , as a colourless liquid having a peppermint odour. Yield, 4 5-5 o g. A small quantity of higher-boiling material remains in the flask. 

Transfer the reaction-mixture to a separating-funnel, run off the aqueous layer, and collect the ethereal layer. Extract the aqueous layer twice with ether (2 x 25 ml.), add the extracts to the main ethereal solution and dry over sodium sulphate. 

Place 80 g, of hydroxylamine sulphate (or 68-5 g. of the hydrochloride), 25 g. of hydrated sodium acetate, and 100 ml. of water in a 500 ml. flask fitted with a stirrer and a reflux water-condenser, and heat the stirred solution to 55-60°. Run in 35 g (42 nil,) of -hexyl methyl ketone, and continue the heating and vigorous stirring for ij hours. (The mixture can conveniently be set aside overnight after this stage.) Extract the oily oxime from the cold mixture twice with ether. Wash the united ethereal extract once with a small quantity of water, and dry it with sodium sulphate. Then distil off the ether from the filtered extract, preferably using a distillation flask of type shown in Fig. 41 (p. 65) and of ca, 50 ml, capacity, the extract being run in as fast as the ether distils, and then fractionally distil the oxime at water-pump pressure. Collect the liquid ketoxime, b.p. 110-111713 mm. Yield, 30-32 g. 

Cool the mixture and pour the liquid reaction product into a separating-funnel. Rinse out the flask (which may contain some unchanged zinc) with ether, pour the latter into the funnel, and extract the aqueous solution with the ether. Repeat the extrac tion with a second quantity of ether, unite the ether extracts, wash them by extracting once with water, and then dry the ethereal extract over sodium sulphate. 

For dehydrogenation, add this ester to dilute nitric acid (20 ml. of the concentrated acid diluted with 40 ml. of water) and boil the mixture under reflux for about 5 minutes, during which the ester gently efferv esces and Anally gives a clear solution. Cool this solution in ice-w ater, make alkaline with aqueous sodium carbonate solution and extract tw ice with ether (50 ml. for each extraction). Dry the extract with sodium sulphate, filter, and then distil using a small distilling-flask... 

If no solid precipitate is obtained but the solution becomes cloudy, a low-melting or liquid phenol is indicated this will, of course, be revealed also by the characteristic phenolic odour. Transfer to a separating-funnel and extract with an equal volume of ether. Separate and dry with anhydrous sodium sulphate. Distil off the ether and identify the residue. 

Cool the remainder of the filtrate and extract three times with ether, using 20 - 30 ml. for each extraction. Dry the combined ethereal extracts over powdered anhydrous sodium sulphate. Filter into a small flask and distil off the ether on a water-bath. Pour the residual oil into a small dish or beaker crystallisation takes place almost immediately. The salicyl alcohol so obtained is almost pure, but it may, if so desired, be recrystallised from a small quantity of benzene. It is a colourless crystalline solid, m.p. 86 , readily soluble in water it gives a violet coloration with ferric chloride. 

It should be noted that the aqueous extract of the turnips shows weak peroxidase activity before precipitation with ammonium sulphate. 

In the isolation of organic compounds from aqueous solutions, use is frequently made of the fact that the solubility of many organic substances in water is considerably decreased by the presence of dissolved inorganic salts (sodium chloride, calcium chloride, ammonium sulphate, etc.). This is the so-called salting-out effect. A further advantage is that the solubility of partially miscible organic solvents, such as ether, is considerably less in the salt solution, thus reducing the loss of solvent in extractions. 

Dichlorobutane. Place 22-5g. of redistilled 1 4-butanediol and 3 ml. of dry pyridine in a 500 ml. three necked flask fitted with a reflux condenser, mechanical stirrer and thermometer. Immerse the flask in an ice bath. Add 116 g. (71 ml.) of redistilled thionyl chloride dropwise fix>m a dropping funnel (inserted into the top of the condenser) to the vigorously stirred mixture at such a rate that the temperature remains at 5-10°. When the addition is complete, remove the ice bath, keep the mixture overnight, and then reflux for 3 hours. Cool, add ice water cautiously and extract with ether. Wash the ethereal extract successively with 10 per cent sodium bicarbonate solution and water, dry with anhydrous magnesium sulphate and distil. Collect the 1 4-dichloro-butane at 55-5-56-5°/14 mm. the yield is 35 g. The b.p. under atmospheric pressure is 154 155°. 

CAUTION. Ethers that have been stored for long periods, particularly in partly-filled bottles, frequently contain small quantities of highly explosive peroxides. The presence of peroxides may be detected either by the per-chromic acid test of qualitative inorganic analysis (addition of an acidified solution of potassium dichromate) or by the liberation of iodine from acidified potassium iodide solution (compare Section 11,47,7). The peroxides are nonvolatile and may accumulate in the flask during the distillation of the ether the residue is explosive and may detonate, when distilled, with sufficient violence to shatter the apparatus and cause serious personal injury. If peroxides are found, they must first be removed by treatment with acidified ferrous sulphate solution (Section 11,47,7) or with sodium sulphite solution or with stannous chloride solution (Section VI, 12). The common extraction solvents diethyl ether and di-tso-propyl ether are particularly prone to the formation of peroxides. 

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