Ammonia buffer solutions

For the increase of sensitiveness of the voltamperometric determination Co(II) use o,o -dihydroxysubstituted azodyes (eriochrome red B and calces). The Co(II) determination can be conducted at potential of reduction of coordinating connection of Co(II)-azodye (E = - 0,9V) and directly the Co(II) (E = -1,2V, ammonia buffer solution) ions. The results of reseaixhes show that selectivity of the Co(II) determination in presence the Ni(II) and Pd(II) ions more high with the use of analytical signal at the potential -1,2V. Is it thus succeeded move aside potentials of peaks of reduction of the Ni(II) and Co(II) ions on a background ammoniac buffer solution from AE=0,2V to AE = 0,4-0,5V. The Co(II) determination can be conducted in presence 50-100 multiple surpluses Ni(II). Palladium in these conditions does not prevent to 60 multiple surplus. 

Ammonia buffer solution. Mix 20 g ammonium nitrate and 35 mL concentrated ammonia solution, and make up to 100 mL with distilled water. Dilute 80 mL to 1 L with distilled water. The pH is about 10.1. 

In solution, the drug may hydrolyze to yield diethylaminoethanol and 4-aminobenzoic acid. For the analysis, the sample solution is treated with 0.2 M (NH4>2Zn(SCN)4, heated to the onset of boiling, and cooled with slow rotational mixing for 4 minutes. This process yields clear solution and an oily precipitate, which is filtered through cotton wool. The filter is washed with 10% NH4SCN solution, and cooled to IT C. The precipitate is dissolved in acetone or dimethylformamide. Water, ammonia buffer solution (pH unspecified), and acid chrome black special indicator are added, and the mixture titrated with 10 mM EDTA to determine Zn(II), and hence procaine. 

Figure 3 - Cyclic voltammograms of Znupo obtained from 0.5mM ZnSOr in a pH 9.2 ammonia buffer solution on Ag(l 11) covered by S (a), Se (b) and Te (c). The scan rate is 40 mV s 1.

Ammonia buffer solution, 4 mol/L Prepared by addition of HCl (final concentration about 2.5 mol/L) to 4mol/LNH3 solution addition of 100/tL of this buffer to 10 mL seawater should give a pH of 9.1. 

Dissolve 1 g in 10 ml of concentrated hydrochloric acid by warming on a water-bath. Dilute with 50 ml of water, cool, transfer to a 250 ml graduated flask and dilute to volume with water. Take 25 ml in a 500 ml flask, add 30 ml of 0 05M EDTA, 10 ml of ammonia buffer solution and 100 ml of water and titrate with 0-1N zinc to solochrome black as indicator. 1 mlOOSM FDTA - 0 005170 g Ca CPO ).. ... 

Transfer a 20 ml aliquot of solution A to a flask, dilute to about 50 ml with water and neutralise with 20 per cent sodium hydroxide solution. Add 5 ml of ammonia buffer solution and titrate with 0-05M EDTA using solochrome black as indicator. Let the ml 0 05M EDTA required be a ml. 

Ignite 2 g in a silica dish, gently until all the fat has burned and then at about 800° to a white ash. Dissolve in 10 ml dilute hydrochloric acid, heating on a water-bath to assist solution. Dilute to 100 ml with water. To 20 ml add 10 ml of ammonia buffer solution and titrate immediately with 0-05M EDTA using solochrome black indicator. 1 ml 0-05M = 0 002016 g MgO. 

Dissolve the residue obtained in the determination of sodium bicarbonate in the minimum volume of dilute hydrochloric acid and dilute to 100 ml with water. To 10 ml add 200 ml of water and neutralise to methyl orange-xylene cyanol with dilute ammonia solution. Add 20 ml of ammonia buffer solution and titrate with 0 05M EDTA using solo-chrome black. The volume of 0 05 M EDTA plus one tenth the volume of 0 05M EDTA required in the sodium bicarbonate determination represents the amount of Mg present. 1 ml 0 05M = 0 001216 g Mg. 

For sodium bicarbonate To 1 5 g add 80 ml of water and boil for five minutes. Filter with the aid of suction, transfer the residue to a beaker, add 100 ml of water and again boil for five minutes. Filter and titrate the combined filtrates with 0 5N hydrochloric acid using methyl orange-xylene cyanol as indicator. To the titrated liquid add 10 ml of ammonia buffer solution and titrate with 0 05M EDTA using solochrome black as indicator. From the ml 0-5N hydrochloric acid required in the first titration, subtract one fifth of the ml 0 05M EDTA required in the second titration and calculate the sodium bicarbonate content from the difference. 1 ml 0 5N HCl = 0 04201 g NaHCOg. 

For magnesium To 25 ml of the prepared solution add 1 g of ammonium chloride, swirl to dissolve and then add sufficient triethanolamine to dissolve the precipitate that first forms. Without delay, dilute to about 200 ml with water and add 5 ml of ammonia buffer solution and sufficient solochrome black indicator to give a good red colour. Titrate immediately wdth 0 05M EDTA to the formation of a full blue colour. 1 ml 0-05M - 0-002016 g MgO. 

Dissolve about 0-3 g of mercuric chloride, accurately weighed, in 100 ml of water, add about 40 ml of 0 05M EDTA (this solution need not be accurately standardised), 5 ml of ammonia buffer solution and 0 5 ml of solochrome black indicator and titrate with 0 05M zinc solution until the blue colour changes to purple (do not overshoot the endpoint) add 3 g of potassium iodide, swirl to dissolve, allow to stand for two minutes and then continue the titration with zinc solution to the same end-point as before. Each ml of zinc solution required after addition of the potassium iodide = 0 01358 g HgCl2. 

To 100 ml of a neutral solution containing about 20 mg of manganese add a small amount of hydroxylamine hydrochloride to prevent oxidation of the manganese. Then add 10 ml of ammonia buffer solution followed by 3 to 5 drops of catechol violet indicator and titrate immediately with 0 01 M EDTA until the colour changes from greenish-blue to reddish-purple. 1 ml O OIM EDTA = 0 0005493 g manganese. 

Weigh 5 g of the sample into a 250-ml separator, add 25 ml of dilute hydrochloric acid, 15 ml of 95 per cent ethanol and 30 ml of chloroform and shake until solution is effected. Allow the layers to separate, run the lower (chloroform) layer into a second separator and extract it with two 10-ml quantities of water. Combine the aqueous phases and wash with two 20-ml quantities of chloroform. Reject the chloroform. Decant the aqueous phase into a 1 -litre graduated flask, wash in with water and make just alkaline to litmus paper with dilute ammonia solution. Add 10 ml of strong ammonia buffer solution and dilute to volume with water. Transfer a 50-ml aliquot to a 150-ml separator and add and dissolve 0-1 g of the disodium salt of EDTA. Continue as described in the general... 

To a weight of sample equivalent to about 0-1 g of zinc oxide, add 10 ml of water and 10 ml of N sulphuric acid and shake until dissolution is as complete as possible. Add 0 5 g of ammonium chloride and a slight excess of dilute ammonia solution and then add sufficient triethanolamine so that the precipitate which first forms redissolves and add a further 3 ml. Dilute to about 200 ml with water and complete by method (viii) (a) above from the addition of the ammonia buffer solution. 1 ml 0 05M EDTA = 0-004069 g ZnO. 

Ammonia buffer solution. Dissolve 13 5 g of ammonium chloride in 130 ml of strong ammonia solution and dilute to 200 ml with water. 

Dissolve about 0 7 g of the acid-washed zinc in the minimum quantity of dilute hydrochloric acid and dilute to exactly 250 ml with water. Transfer a 25-ml aliquot to a flask, add 125 ml of water and 10 ml of ammonia buffer solution and titrate with the EDTA solution using solochrome black as indicator. 1 ml 0 05M EDTA = 0 003269 g zinc. 

A polarogram of a ketimine was first obtained by Zuman [6], who showed that the imine was reduced when acetone was dissolved in ammonium - ammonia buffer solution. The limiting current here corresponded to the equilibrium concentration in the body of the solution. Zuman then proposed the use of the less volatile primary amines in place of ammonia. He also discovered the first limitations of the method — benzophenone and acetoacetic ester could not be determined in this way [7]. There thus was available a very simple and convenient method for determining carbonyl compounds, and its details are still being developed to this day [8-13]. The method can also be used to detect aliphatic amines [12, 14, 15]. 

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