Aluminium acetate solution

If a dyeing test with cotton is required, this is mordanted by boiling with 5% aluminium acetate solution and then exposed for some time to hot, moist air for each gram of cotton 20 c.c. of the extract solution are used. 

H. 8-Hydroxyquinaldine (XI). The reactions of 8-hydroxyquinaldine are, in general, similar to 8-hydroxyquinoline described under (C) above, but unlike the latter it does not produce an insoluble complex with aluminium. In acetic acid-acetate solution precipitates are formed with bismuth, cadmium, copper, iron(II) and iron(III), chromium, manganese, nickel, silver, zinc, titanium (Ti02 + ), molybdate, tungstate, and vanadate. The same ions are precipitated in ammoniacal solution with the exception of molybdate, tungstate, and vanadate, but with the addition of lead, calcium, strontium, and magnesium aluminium is not precipitated, but tartrate must be added to prevent the separation of aluminium hydroxide. 

Discussion. Some of the details of this method have already been given in Section 11.11(C), This procedure separates aluminium from beryllium, the alkaline earths, magnesium, and phosphate. For the gravimetric determination a 2 per cent or 5 per cent solution of oxine in 2M acetic add may be used 1 mL of the latter solution is suffident to predpitate 3 mg of aluminium. For practice in this determination, use about 0.40 g, accurately weighed, of aluminium ammonium sulphate. Dissolve it in 100 mL of water, heat to 70-80 °C, add the appropriate volume of the oxine reagent, and (if a precipitate has not already formed) slowly introduce 2M ammonium acetate solution until a precipitate just appears, heat to boiling, and then add 25 mL of 2M ammonium acetate solution dropwise and with constant stirring (to ensure complete predpitation). 

The precipitate is soluble in free mineral acids (even as little as is liberated by reaction in neutral solution), in solutions containing more than 50 per cent of ethanol by volume, in hot water (0.6 mg per 100 mL), and in concentrated ammoniacal solutions of cobalt salts, but is insoluble in dilute ammonia solution, in solutions of ammonium salts, and in dilute acetic (ethanoic) acid-sodium acetate solutions. Large amounts of aqueous ammonia and of cobalt, zinc, or copper retard the precipitation extra reagent must be added, for these elements consume dimethylglyoxime to form various soluble compounds. Better results are obtained in the presence of cobalt, manganese, or zinc by adding sodium or ammonium acetate to precipitate the complex iron(III), aluminium, and chromium(III) must, however, be absent. 

Determination of zinc as 8-hydroxyquinaldinate Discussion. Zinc may be precipitated by 8-hydroxyquinaldine (2-methyloxine) in acetic acid-acetate solution it can thus be separated from aluminium and magnesium [see Section 11.11(G)]. It can be weighed as Zn(C10H8ON)2 after drying at 130-140 °C. The co-precipitated reagent is volatile at 130 °C. 

Aluminium. 25.0 mL aluminium ion solution, acidified with a few drops of 2.5M nitric add (to pH 1-2), boiled for 1 minute, 50.0 mL 0.05M EDTA added to hot solution, solution cooled, 50 mL acetate buffer and 1 drop of 0.0025 M mercury-EDTA added, excess of EDTA back-titrated with standard zinc ion solution. 

Procedure. Into lOOmL graduated flasks, each containing lOmL of the ammonium acetate solution, 1 mL of the dilute sulphuric acid, and 3 mL of the eriochrome blue black RC solution, run in from a burette 15.0, 20.0, 25.0, 30.0, 35.0, 40.0, 45.0, and 50.0 mL of the standard aluminium solution. Dilute each of the above solutions with distilled water, and adjust to a pH of 4.6 0.2 if necessary before making up to the 100 mL mark. Allow the solutions to stand for at least 1 hour. 

In another experiment, different volumes (2.5, 5.0 and 10.0 ml) of 4,000 ppm solution of sodium acetate was added to 10.0 ml of 1,000 ppm solution of aluminium sulphate. In the normal reaction, no precipitate was obtained in cold and neutral solutions, but on boiling with excess reagent, a voluminous precipitate of basic aluminium acetate, Al(OH)2COOCH3, was formed. 

Sodium acetate solution no precipitate is obtained in cold, neutral solutions, but on boiling with excess reagent, a voluminous precipitate of basic aluminium acetate Al(OH)2CH3COO is formed ... 

Iron interferes with the test and should be absent. Chromium forms a similar lake in acetate solution, but this is rapidly decomposed by the addition of the ammoniacal ammonium carbonate solution. Beryllium gives a lake similar to that formed by aluminium. Phosphates, when present in considerable quantity, prevent the formation of the lake. It is then best to precipitate the aluminium phosphate by the addition of ammonia solution the resultant precipitate is redissolved in dilute acid, and the test applied in the usual way. 

Separation. Beryllium is precipitated in Group IIIA. It is ultimately associated with aluminium in solution as tetrahydroxoaluminate and tetrahydroxoberyllate respectively. Upon diluting and boiling, only the Be(OH)2 is precipitated. Alternatively, the quinalizarin test, 7, may be applied to the solution or the basic acetate-chloroform test, 6, to the mixed hydroxides. Beryllium may also be detected in the presence of aluminium by the acetylacetone test, 9 this is specific for Be. 

Water is the most important component. Wet dressings are generally used to cleanse, cool and relieve pruritus in acutely inflamed lesions, especially where there is much exudation, e.g. atopic eczema. The frequent reapplication and the cooling effect of evaporation of the water reduce the inflammatory response by inducing superficial vasoconstriction. Sodium chloride solution 0.9%, or solutions of astringent substances, e.g. aluminium acetate lotion, or potassium permanganate soaks or compresses of approx. 0.05%, can be used. The use of lotions or... 

Calamine and astringents (aluminium acetate, tannic acid) may help. Local anaesthetics do not offer any long-term solution and since they are liable to sensitise the skin they are best avoided lignocaine is least troublesome in this respect. Topical doxepin... 

Stabilized emulsion of paraffin wax, and the recommended treatment is by a two-bath process in which the wax is applied first and the cloth is subsequently transferred to a liquor containing a metallic salt such as aluminium sulphate. Insoluble soaps have found extensive use in making water-repellent materials. In practice, aluminium soap is most favoured. The fabric is soaked, first in a soap solution and, after squeezing, in a bath containing alum. It is then dried and hot pressed to melt the aluminium soap so that it will be evenly spread and will adhere firmly. As an example, the first liquor might well be a 0-2 per cent soap solution, and the precipitating bath might contain a 0-1 per cent solution of aluminium acetate. 

Aluminium acetate, known as red liquor, or mordant rouge, is used in dyeing for the production of red colour. One method of preparation is to add a solution of alum to acetate of lime liquor. The lime is precipitated as sulphate, its place being taken by the aluminium forming the acetate. 

M en freshly precipitate, it is insoluble in H,0 soluble in acids and solutions of the fixed alkalies. When dried at a temperature above 50° (122° F ), or after 24 hours contact with the mother liquor, its solubility is greatly diminished. With acids it forms salts of aluminium and with alkalies, aluminates of the alkaline metal. Heated to near redness it is decomposed into A1,0, and H O. A soluble modification is obtained by dialysing a solution of ALH O in A1,C1 or by heating a dilute solution of aluminium acetate for 0 houra... 

Fixation of the mordant The fixation is mostly achieved by drying of the textile at low temperature. Kiel showed that the formation of Al(OH)3 out of aluminium acetate mordant and sulphonate mordant is essential for the fixation. He demonstrated that the deposition of Al(OH)3 in the fibres was maximal if the pH lies between 4 and 9 during the fixation. At pH < 4 or pH > 9 the Al(OH)3 dissolves again. Kiel found that fixation of the textile at 40°C for 30 min or 1 min at 70°C in 3 ml sodium silicate solution (or 10 g chalk/L) are the best conditions [20]. 

This dye is adsorbed by aluminium hydroxide giving a bright-red adsorption complex or lake . The test is applied to the precipitate of aluminium hydroxide obtained in the usual course of analysis, since certain other elements interfere. Dissolve the aluminium hydroxide precipitate in 2 ml 2m hydrochloric acid, add 1ml 6m ammonium acetate solution and 2 ml... 

Aqueous solutions for the external canal that do not contain a preservative are an exception. They get a shelf life of 2 weeks at 2-8 °C (refrigerated). An example is tenfold diluted Aluminium-acetate or -acetotartrate ear drops (see also Sect. 9.5.7). 

Amorphous silica was prepared by mixing the silica gel powder Aerosil A-175 with ammonium acetate solution. The obtained paste was molded via extmsion and dried in air first at room temperature, then at 100 C for 10-15h. The samples were calcined under air flow at 550 °C for 10-15h. a-Alumina was obtained via thermal decomposition of Y-AI2O3 for 12h at T = 1250 °C. yAlumina was obtained via thermal decomposition of pseudoboehmite at 500 C for 5 h. The latter was synthesized via aluminium nitrate solution treatment with ammonia. 

The glycerolipid (1 to 10 mg) and a known amount of a suitable methyl ester as an internal standard, say methyl pentadecanoate, are dissolved in dry diethyl ether (2 mL), and an ethereal solution of lithium aluminium hydride (20 mg in 3 mL) is added in portions of 0.1 mL until the boiling stops. After addition of a one volume excess of the lithium aluminium hydride solution, the mixture is refluxed for 1 hour. Acetic anhydride is added drop-wise with cooling to destroy the excess reagent, followed by additional acetic anhydride (2.5 mL) and xylene (3 mL). The ether is removed by evaporation and the residue is refluxed for 6 hours the temperature should reach 110 C if no ether remains. Finally, the reagents are removed on a rotary evaporator and the products are taken up in dry diethyl ether for analysis by GC."... 

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