Ammonium / potassium separation

FIGURE 10 Separation of ammonium, potassium, caicium, sodium, magnesium, and iithium at 20pg/mL with iSmM imidazoie, 2mM i8-crown-6 and 33 mM acetic acid as BGE. Linearity between 2 and 20 mg/L with an R >0.999 for aii anaiytes. indirect UV detection at 205 nm (iOnm bandwidth). 

Carnotite may be fused Avith potassium hydrogen sulphate and the residue extracted with Avater. From the solution the double sulphates of potassium AAuth uranium and vanadium may be obtained by crystallisation. These are reduced by means of zinc and sulphuric acid, and the vanadium precipitated from the solution by means of ammonia and ammonium carbonate. Ammonium diuranate separates from the filtrate on boiling. ... 

Identification Talc is added to a melt of anhydrous sodium carbonate and anhydrous potassium carbonate and heated until fused. Hot water and hydrochloric acid are then added to the cooled mixture, and heated to dryness. The remaining solid is boiled in water, and the insoluble silica residue is filtered off. Ammonium chloride and ammonium hydroxide are dissolved in the filtrate. The solution is filtered if necessary and dibasic sodium phosphate TS is added to the filtrate. A white crystalline precipitate of magnesium ammonium phosphate separates. 

Fig. 3-137. Dependence of the retention of monovalent cations on the ionic strength of the eluent for sodium, ammonium, and potassium. - Separator column IonPac CS1 eluent HC1 flow rate 2.3 mL/min detection suppressed conductivity.

Fig. 6-19. Indirect photometric detection of sodium, ammonium, and potassium. - Separator column Dowex 50 eluent 0.005 mol/L copper sulfate flow rate 0.7 mL/min detection UV (252 nm, indirect) injection volume 20 pL solute concentrations 230 ppm sodium, 180 ppm ammonium, and 391 ppm potassium (taken from [29]).

The simultaneous analysis of alkali and alkaline-earth metals is another important ion chromatographic application in the field of drinking and surface water analysis. The corresponding chromatogram in Fig. 8-4 shows the separation of sodium, ammonium, potassium, magnesium, and calcium in less than 20 minutes. It was obtained with a separator column IonPac CS10 which was described in Section 3.4.4. 

A mixture of 50 c.c. of 25 per cent, ammonia, 25 c.c. of 50 per cent, chromic acid, and 75 c.c. of water is cooled until ice begins to separate 25 c.c. of 30 per cent, hydrogen dioxide is added, drop by drop, with constant shaking and keeping the temp, below 0°. The soln. becomes at first reddish-yellow, and then brownish-black, and in one or two hours, crystals of the ammonium salt separate out. These are washed with 95 per cent, alcohol tmtil the runnings show no coloration due to chromic acid. The salt is dried with ether, or on a porous tUe. The sodium and potassium salts can be obtained in an analogous manner. 

The chromatogram from the analysis of a mixture of alkali and alkaline earth cations at levels of a few parts per million is shown in figure 7.14. The cations lithium, sodium, ammonium, potassium, magnesium and calcium were present in the original mixture at concentrations of 1,4, 10, 10, 5 and 10 ppm respectively. The separation obtained is shown in figure 7.14. A proprietary ion exchange column, IonPacCS12, was used and the mobile phase consisted of a 20 nM methanesulfonic acid solution in water. A flow rate of 1 ml/min was employed and the sample volume was 25 pi. 

Emulsions are extracted with pentane or hexane, which separates the emulsion and, after concentrating the solution, high-temperature GC is used to identify oil and wax. The residue from the organic extraction is dried and extracted with hot water to dissolve oxidizer(s). Testing of the water extract by spot tests or IC identifies ammonium, potassium, nitrate, and perchlorate ions when potassium perchlorate is used for increased sensitivity. Identification of the emulsifying system has potential for further characterization of emulsions. The residue from the water extract is primarily aluminum... 

FIA—CE has also been coupled with contactless conductivity detection (C4D) for online analysis of metal cations (ammonium, potassium, calcium, magnesium, and sodium as complexes in aqueous 18-crown-6-ether-acetace electrolyte solution) [86]. In this system the ends of the separation capillary and the electrodes were placed opposite to each other into tubings which acted as flow-through channels. 

Fig. 4-75. Gradient elution of quaternary ammonium compounds. — Separator column lonPac CS12A eluant H2S04-acetonitrile gradient 11 mmol/L H2S04-acetonitrile (90 10 v/v) to 11 mmol/L H2S04-acetonitrile (20 80 v/v) in 15 min flow rate 1 mL/min detection suppressed conductivity injection volume 25 pL solute concentrations 0.3 mg/L sodium (1), 2 mg/L ammonium (2). 5 mg/L potassium (3). 5 mg/L tetramethylammonium (4), 8 mg/L calcium (5), 20 mg/L tetraethyl-...

I Chloroform. Shake 250 ml of chloroform with 25 ml of water containing 1 ml of 10 per cent potassium cyanide solution and about 20 drops of 5M ammonium hydroxide, separate and reject the aqueous layer, wash the chloroform with water and filter. 

It was originally separated from zirconium by repeated recrystallization of the double ammonium or potassium fluorides by von Hevesey and Jantzen. Metallic hafnium was first prepared by van Arkel and deBoer by passing the vapor of the tetraiodide over a heated tungsten filament. Almost all hafnium metal now produced is made by reducing the tetrachloride with magnesium or with sodium (Kroll Process). 

A solution of 0.22 mol of butyllithium in 150 ml of hexane was cooled below -40°C and 140 ml of dry THF were added. Subsequently 0.20 mol of 1-dimethyl amino--4-methoxy-2-butyne (see Chapter V, Exp. 14) were added in 10 min with cooling between -35 and -45°C. After an additional 15 min 100 ml of an aqueous solution of 25 g of ammonium chloride were added with vigorous stirring. After separation of the layers four extractions with diethyl ether were carried out. The solutions were dried over potassium carbonate and then concentrated in a water-pump vacuum. Distillation of the residue gave a mixture of 8-10% of starting compound and 90-92% of the allenic ether, b.p. 50°C/12 mmHg, n 1.4648, in 82% yield (note 1). 

Potassium and ammonium dichromates are generally made from sodium dichromate by a crystallization process involving equivalent amounts of potassium chloride or ammonium sulfate. In each case the solubiHty relationships are favorable so that the desired dichromate can be separated on cooling, whereas the sodium chloride or sulfate crystallizes out on boiling. For certain uses, ammonium dichromate, which is low in alkaH salts, is required. This special salt may be prepared by the addition of ammonia to an aqueous solution of chromic acid. Ammonium dichromate must be dried with care, because decomposition starts at 185°C and becomes violent and self-sustaining at slightly higher temperatures. 

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