RU1770898C - Method of regenerating anion exchange chromatograph column - Google Patents

Description

(21) 4870121/25 (22) 09/28/90 (46) 10/23/92. Bull. Number 39

(71) Institute of Geochemistry and Analytical Chemistry. In I. Vernadsky

(72) A.N. Krachak and A.M. Dolgonosoy

(56) Gutsanu V.L., Labunska I.Ya. Optimization of the dissolution process of FeOOH formed in the phase of highly basic anion exchangers. J. Physical Chemistry, 1986, v. 60, No. 12, p. 3113

Liquid ion chromatograph. Color - 3006, technical description and operating instructions 5E1.550.151 TO. Dokba NPO Himavtomatika, 1984, p. 17, p. 4.4.

(54) METHOD FOR REGENERATING ANIONOCHEMIC CHROMATOGRAPHIC COLUMN

(57) Usage: analytical chemistry, ion-exchange technology. SUMMARY OF THE INVENTION: A method for regenerating anion-exchange chromatographic columns involves desorbing contaminants in a sequentially regenerating solution and an alkali solution. As a regenerating solution, an aqueous solution of a mixture of soluble salts of iodate, iodide and mineral acid is used in a ratio of 1: (8-11): 6 eq / eq / eq and an amount providing absorption of at least 1 mol per 1 mol of the total exchange capacity of the anion exchange resin . The alkali solution is used in an amount of at least 2 mol per 1 mol of the total exchange capacity of the anion exchange resin. 2 ill.

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The invention relates to the field of analytical chemistry, in particular, ion chromatography, and can also be used in ion exchange technology.

A known method for the regeneration of highly basic anion exchangers is that the sorbent is treated with a 28% sulfuric acid solution at 96 ° C for 3 hours. In this case, all contaminants, including the hydroxide complex of iron / 3-FeOOH, are removed from the sorbent.

The closest technical solution to the proposed one is the method of sorbent regeneration in a chromatographic column, which consists in passing through a column with an anion exchanger 200 ml of a 0.5 M solution of 2CO3 in 15% ethanol, then 100 ml of 0.5 M NaOH. The method is used to regenerate sorbents without unloading them from the columns; however, using this method it is impossible to remove iron hydroxide complex 111 | / J-FeOOH from highly basic anion exchangers (anion exchangers with quaternary ammonium bases).

The aim of the invention is to ensure complete restoration of the initial characteristics of chromatographic columns.

This goal is achieved by the fact that in the method of regeneration of the anion-exchange chromatographic column, including desorption of contaminants sequentially with a regenerating solution and an alkali solution, an aqueous solution of a mixture of soluble salts of iodate, iodide and mineral acid in a ratio of 1: (8-11) is used as a regenerating solution : 6 eq / eq / eq and the amount that ensures the absorption of at least 1 mol of lolium iodide ion per 1 mol of the total exchange capacity of the anion exchange resin.

In FIG. 1 shows the dependence of the degree of regeneration of a column filled with XI XJ

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with the Kank-ASt sorbent 6x100 mm in size with passing a solution of a mixture of KI, KYuZ and HCI at a rate of 2.5 ml / min. The sum of the concentrations of the components is 0.1 mol / l, the ratio of Hs: l-: H + 1: 8: 6 () and 0.13 mol / l is 1: 11: 7 or more (2): in FIG. 2 - dependence of the degree of column regeneration on the amount of missed 1 M NaOH solution.

The authors are not aware from other sources of information a regenerating solution of the proposed composition, the use of which allows one to obtain a previously unattainable effect - a complete restoration of the initial characteristics of the chromatographic column. The proposed method uses a dynamic ion-exchange process

KA-Chz Rch1z + L. (I)

where A is a tanning agent (e.g., FeOa). The ion exchange contagion for the pair on highly basic anion exchangers is 10, which ensures the effective desorption of any contaminant ion. It can be seen from equation (1) that at least 1 mol per 1 mol of apion exchange capacity is necessary for the complete regeneration of ammonite.

The formation of a polyiodide ion in a regenerating solution is described by the reaction 8G + 10S + 3H20. (2)

from which it can be seen that for the process to be carried out at 1 eq., at least 8 eq. is required (otherwise a precipitate te) and Oeq. H1. The table shows the characteristics of the regenerating solution at various ratios of Hs: G.

Thus, when using a chip of a concentration of 0.5 g-at / L I and higher, the stoichiometric ratio Hs: is enough. When going to lower concentrations of the regenerating solution, this ratio increases to 1:11 to ensure the solubility of the resulting 2. The use of solutions with a lower ion content is impractical due to the increase in the duration of the process. For greater equilibrium bias (2)

 The formation of sediment in solution. The mixture is unsuitable for work, complete dissolution of the components. The mixture is suitable for work.

to the right, this ratio can be increased to 1/11/6 eq / eq / eq, respectively (see Fig. 1). Excess acid is avoided to prevent corrosion of equipment.

For the subsequent conversion of the anion exchange resin to a less stable I form (the exchange constant Г - С on the same anion exchange resin is about 20), it is enough to destroy the z-form with alkali

by reaction

ZHz + 60H 23RJ + 5r + IO z + ZN20. (3) It follows from the stoichiometric ratios of reaction (3) that the alkali consumption should be at least 2 mol per 1 mol s (see

FIG. 2).

Then the obtained 1-form of anion exchange resin is transferred to any desired form with an appropriate concentrated solution,

Example. Through dividing column

for ion chromatography with a diameter of 6 mm and a length of 100 mm, containing the sorbent Kank-AST 5, 50 ml of a 0.2 M Nal mixture was passed. 0.025 M CMOs and 0.15 M NMOs. Thereafter

50 ml of a 1 M KOH solution are passed through the column. After washing the column thus prepared with eluent

(20-30 ml) it can be included on the scheme of an ion chromatograph.

Claims (1)

Formula invented and A method for regenerating an anion-exchange chromatographic column, including the desorption of contaminants in series with a regenerating solution and a solution alkalis, characterized in that, in order to ensure full restoration of the initial characteristics of the chromatographic columns, a regenerating solution is used an aqueous solution of a mixture of soluble salts of iodate, iodide and mineral acid in a ratio of 1: (8-11): 6 eq / eq / eq, respectively, and an amount providing absorption of at least 1 mol of polyiodidione per 1 mol of the total exchange capacity of anion exchange resin. Flag 1 1,0 and  t + ЈЈЈ- Js 0, / SE ML.