Anion-exchange, chloride column

Takeuchi et al. [343] described an indirect photometric detection method for anions in micro high performance liquid chromatography. Micro anion exchange octadecylsilica columns permanently coated with the hydrophobic cetyltrimethylammonium ion (cetrimide) were used in the high performance liquid chromatography of chloride, nitrate... 

For the mutual separation of plutonium and neptunium, both of those are adsorbed on an anion-exchange resin column and the resin converted to chloride form by washing with concentrated hydrochloric acid. Then the plutonium is reduced to the trivalent state and eluted with 9 H hydrochloric acid solution containing 0.1 M hydro-iodic acid. 

Figure 3.190 Separation of clodronate and potential ionic impurities on a hydroxide-selective anion exchanger. Separator column lonPac ASS column temperature 45 °C eluent NaOH gradient 20-100mmol/L in 20 min flow rate 1 mUmin detection suppressed conductivity peaks (1) chloride, (2) nitrate, (3) diester of dichloro methylene-...

Figure 5.21 Schematic representation of the fractionation for the separation of chloride and fluoride on an ion-exclusion column with subsequent preconcentration on an anion exchanger. Separator column lonPac ICE-AS6 ...

Anionics only present. Remove the anionics on a column of either a strongly basic anion exchanger chloride or a weakly basic anion exchanger hydrochloride. The effluent contains the amphoteric and the displaced chloride ions. For SW amphoterics ensure that the solution entering the column is acid, so that the amphoteric is in the zwitterionic form and will therefore not be retained. 

Column 2 strongly basic anion exchanger chloride, or weakly basic anion exchanger hydrochloride. Retains anionics. 

Prepare a column containing about 40meq of a strongly basic anion exchanger chloride in 80% methanol. 

Fig. 3-90. Separation of halide ions on an acrylate-based anion exchanger. - Separator column lonPac AS9-SC eluant 3 mmol/L Na2C03 flow rate 2 mL/min detection suppressed conductivity injection volume 100 pL solute concentrations 0.3 mg/L fluoride (1), 0.4 mg/L chloride (2). 1 mg/L each of bromide (3), nitrate (4), and orthophosphate (5). 2 mg/L sulfate (6), and 1 mg/L iodide (7) ...

For an amine (weak base) anion-exchange column in its chloride form, the following order has been observed ... 

Choline chloride [67-48-1] M 139.6, m 302-305 (dec). Extremely deliquescent. Purity checked by AgN03 titration or by titration of free base after passage through an anion-exchange column. Crystd from absolute EtOH, or EtOH-diethyl ether, dried under vacuum and stored in a vacuum desiccator over P2O5 or Mg(C104)2. 

Example. A mixture of ca 0.05 mmole each of chloride and bromide ions is to be separated on an anion exchange column of length 10 cm and 1cm2 cross-section, using 0.035M potassium nitrate as the eluant. The distribution coefficients (Kd) for the chloride and bromide ions respectively are 29 and 65. 

Anion exchange resin. Proceed as in the previous experiment using 1.0 g, accurately weighed, of the air-dried strongly basic anion exchanger (e.g. Duolite A113, chloride form). Fill the 250 mL separatory funnel with ca 0.25M sodium nitrate solution, and allow this solution to drop into the column at the rate of about 2 mL per minute. Collect the effluent in a 500 mL conical flask, and titrate with standard 0.1M silver nitrate using potassium chromate as indicator. 

Procedure. Prepare a column of the anion exchange resin using about 15 g of Duolite Al 13 in the chloride form (Section 7.9). The column should be made up in 2 M hydrochloric acid. 

Theory. The anion exchange resin, originally in the chloride form, is converted into the nitrate form by washing with sodium nitrate solution. A concentrated solution of the chloride and bromide mixture is introduced at the top of the column. The halide ions exchange rapidly with the nitrate ions in the resin, forming a band at the top of the column. Chloride ion is more rapidly eluted from this band than bromide ion by sodium nitrate solution, so that a separation is possible. The progress of elution of the halides is followed by titrating fractions of the effluents with standard silver nitrate solution. 

Procedure. Prepare an anion exchange column (Section 7.8) using about 40g of Duolite A113 (chloride form). The ion exchange tube may be 16 cm long and about 12 mm internal diameter. Wash the column with 0.6M sodium nitrate until the effluent contains no chloride ion (silver nitrate test) and then wash with 50 mL of 0.3 M sodium nitrate. 

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