Barium chloride extract

ISO 14254 2001 Soil quality - Determination of exchangeable acidity in barium chloride extracts. 

The K concentrations in the barium chloride extracts are presented in Fig. 2. The results show a highly significant (p < 0.01) enrichment in K following the order inner rhizosphere > outer rhizosphere > bulk soil. The K concentrations in... 

Fig. 2. Mean K concentration in the barium chloride extractions in the inner rhizosphere (RHi), the outer rhizosphere (RHo) and the bulk soil (BK) at all sites (0.5, 2 and 8 km from a smelter) and for the three field replicates (A, B and C). Values are means of two or three replicates depending on the soil mass available. Error bars represent the standard deviation when analyses were performed in triplicates.

Our study with acidic soils indicates the presence of HIV in the rhizosphere as evidenced by a broad peak at about 1.2 nm under K saturation. Yet, our results for barium chloride-extractable K show a clear enrichment of K in the rhizosphere (Fig. 2) rather than the depletion expected based on the Hinsinger et al. 

Extract the acidified solution with ether, remove the ether and identify the phenol in the usual manner (see Section IV,114).f Add a few drops of bromine water or nitric acid to the aqueous layer and test for sulphate with barium chloride solution. 

The process of isolation finally adopted by the former authors consists in precipitating as reineckates the water-soluble bases contained in a methyl alcoholic extract of the curare. The mixed reineckates are further purified, by solution in acetone and precipitation with water as often as may be necessary. The product so cleaned represents the bulk of the biological activity of the crude drug the mother liquors may contain curine (p. 374), which indicates a menisperm as one of the components of such curares. The mixed reineckates are then fractionated chromato-graphically over alumina and the components isolated as chlorides by the use of silver sulphate and barium chloride in succession. This process has been modified in detail by Schmid and Karrer, who have also found that with their curare, the more soluble reineckate fraction includes less potent quaternary alkaloids. 

In order to suppress interferences due to the presence of inorganic species and reliably determine the proteinaceous composition of the sample, a clean-up step has often been introduced in the analytical procedure. This step may include the extraction of the proteinaceous matter by an ammonia solution [8], the use of a cation-exchange resin [8,55], a chelating agent [9,41,44], the use of a Cig resin or the use of barium chloride solution to suppress sulfates [10,81,82]. Table 9.1 reports the methods used to overcome such problems. 

Activated charcoal, purified - place about 50 g Darco C-5 activated carbon in a wide-neck screw-cap container, add sufficient calcium phosphate extractant to completely wet it, then cap the bottle and shake for 5 min. Filter slowly with suction through a Buchner funnel, then wash three times successively with deionized water. Test the final leachate with a solution of barium chloride (approximately 1.4% m/v in 0.3 M HCI). If turbidity indicates the presence of sulphate, return the charcoal to a beaker, thoroughly mix with deionized water (boil for 15 min if necessary to get a clear test), refilter, wash and test for S as above. When satisfactory, dry overnight at 105°C and store in a tightly capped bottle. 

Lithium.—In order to extract lithium from the silicate minerals—petalite, lepidolite, spodumene, amblygonite, etc.—J. J. Berzelius 3 fused the finely powdered mineral with twice its weight of calcium or barium carbonate. L. Troost fused a mixture of finely powdered lepidolite with an equal weight of barium carbonate, half its weight of barium sulphate, and one-third its weight of potassium sulphate. In the latter case, two layers were formed lithium and potassium sulphates accumulated in the upper layer from which they were extracted by simple lixiviation. The sulphates are converted to chlorides by treatment with barium chloride. The filtered liquid is evaporated to dryness, and the chlorides extracted with a mixture of absolute alcohol, or pyridine. The lithium chloride dissolves, the other alkali chlorides remain as an almost insoluble residue. 

Sulphurous Anhydride.—The total sulphurous anhydride (free and combined) is determined by distilling a few grams of the extract (weighed exactly), after dilution with water and treatment with a little phosphoric add. The distillate is caught in a solution of iodine in potassium iodide, in which the sulphuric add is subsequently predpitated by barium chloride... 

Fatty Substances and Free Sulphur.—The fats are determined as with tanned leather, carbon disulphide free from sulphur being used for the extraction. If the leather contains free sulphur, this occurs with the fat thus extracted. In such case, when the extracted matter is weighed, it is carefully oxidised in a platinum dish with fuming nitric acid to complete solution the acid is then evaporated off on a water-bath, the residue neutralised with concentrated sodium carbonate solution, the liquid taken to dryness and the residue ignited. This residue is dissolved, in water, the solution acidified with hydrochloric acid, the oxidation completed by boiling with a little bromine water, and the sulphate precipitated with barium chloride. The amount of sulphur corresponding with the... 

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