A method for one-step chemical separation of nickel from rock samples using a combined resin column

Abstract

The present application relates to the technical field of analytical chemistry and isotope geochemistry, and particularly relates to a method for one-time chemical separation of nickel in a rock sample by using a combined resin column, which comprises the following steps: firstly, adding a rock sample solution into a cation resin column, and sequentially eluting the cation resin column by using a mixed solution of 0.2 mol / L ammonium citrate and 3 mol / L ammonia water and 0.5 mol / L HCl; then, arranging an anion resin column below the cation resin column, eluting the cation resin column by using 10 mol / L HCl, and flowing the solution through the cation resin column into the anion resin column, and flowing the nickel through the anion resin column. The method has higher efficiency than the currently published chemical separation method of nickel, does not use organic reagents such as acetone, has small environmental pollution, has small irritation to experimenters, does not need to adjust the pH value, is simple to operate, improves the experimental efficiency, and simultaneously increases the stability of the results.

Description

Technical Field

[0001] This invention relates to the fields of analytical chemistry and isotope geochemistry, specifically to a method for the one-time chemical separation of nickel from rock samples using a combined resin column. Background Technology

[0002] Nickel (Ni) isotope geochemistry is an important component of stable metal isotope geochemistry, with significant applications in astrochemistry, petrology, and paleoenvironmental evolution studies. Nickel isotope analysis techniques for rock samples consist of two parts: Ni chemical separation and Ni isotope instrumental analysis. The main drawback of existing Ni isotope analysis techniques lies in the Ni chemical separation method. Ni chemical separation primarily employs ion exchange, commonly known as "column chromatography." After the rock sample is dissolved in acid, it becomes ionic, with metal ions dissolving in the acid solution. The acid solution containing metal ions is loaded onto a resin, where the metal ions bind and adsorb. Since the binding affinity between metal ions and resin differs, after rinsing with the acid solution, the weaker ions gradually elute, achieving elemental separation.

[0003] In existing technologies, Ni chemical separation typically employs anion exchange resins and cation exchange resins, combined with Ni-specific resins to adsorb Ni and matrix elements. The resins are then eluted with solutions of hydrochloric acid, nitric acid, and acetone of varying concentrations to achieve separation. This process involves at least two chemical separations to separate Ni from the matrix elements. However, existing methods have the following shortcomings:

[0004] 1. The separation process is complex. Existing methods employ multiple ion exchange resins and require at least two chemical separations to fully separate Ni from other elements in rock samples. After each chemical separation, the solution needs to be evaporated, hydrochloric acid or nitric acid is added as a conversion medium, and the sample is dissolved again before proceeding to the next chemical separation step. Multi-step chemical separation methods are time-consuming and require more chemical reagents.

[0005] 2. The use of Ni-specific resin is time-consuming (pH adjustment) and requires a high level of experimental skill. The resin is a disposable consumable, requiring replacement before each experiment; it is also expensive; currently, all Ni-specific resins are imported, with no domestic alternatives available, resulting in long procurement cycles and impacting experimental progress.

[0006] 3. The use of acetone in the experiment caused a strong irritant effect on the subjects.

[0007] 4. Even after chemical separation, small amounts of Mn and Mg may remain in the sample. Excessive Mn and Mg content in the sample can lead to matrix effects, causing Ni isotope analysis results to deviate from the true values. Furthermore, Mn and Mg may enter the instrument during analysis, increasing the background levels of Mn and Mg within the instrument and affecting instrument performance and other isotope analyses. Summary of the Invention

[0008] In view of the above-mentioned shortcomings in the prior art, the present invention provides a method for one-time chemical separation of nickel from rock samples using a combined resin column, which solves the problems of long process, incomplete element separation, high requirements for experimental operation skills, and use of irritating reagents in the existing nickel chemical separation methods.

[0009] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0010] A method for the one-step chemical separation of nickel from rock samples using a combined resin column is provided, comprising the following steps:

[0011] First, the rock sample solution was added to a cation exchange resin column, and the column was eluted sequentially with a mixed solution of 0.2 mol / L ammonium citrate + 3 mol / L ammonia and 0.5 mol / L HCl. Then, an anion exchange resin column was placed below the cation exchange resin column, and the column was eluted with 10 mol / L HCl. The solution passed through the cation exchange resin column and flowed into the anion exchange resin column, while nickel flowed out through the anion exchange resin column.

[0012] Furthermore, the cation exchange resin is AG50W-X8.

[0013] Furthermore, the anion exchange resin is AG1-X8.

[0014] Furthermore, the specific steps include:

[0015] 1.5 ml of AG50W-X8 cation exchange resin was packed into a PP resin column to form a cation exchange resin column; 6 ml of 6 mol / L HCl, 10 ml of pure water, and 5 ml of a mixed solution of 0.2 mol / L ammonium citrate and 3 mol / L ammonia were added sequentially to equilibrate the cation exchange resin column; 2 ml of sample solution was added to the cation exchange resin column, and then the cation exchange resin column was rinsed sequentially with a mixed solution of 0.2 mol / L ammonium citrate and 3 mol / L ammonia and 0.5 mol / L HCl.

[0016] An anion exchange resin column was set up below the cation exchange resin column. The anion exchange resin column was filled with AG1-X8 anion exchange resin, and 10 ml of 10 mol / L HCl was added to rinse the anion exchange resin column. Then, 5 ml of 10 mol / L HCl was used to rinse the cation exchange resin column. The solution passed through the cation exchange resin column and flowed into the anion exchange resin column. Nickel flowed directly out through the anion exchange resin column, thus completing the separation of nickel from the matrix element.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. Shortened chemical separation process. This invention uses a combined resin column to perform a single chemical separation of Ni in rock samples, which reduces the time and improves efficiency compared to existing processes requiring at least two chemical separation steps.

[0019] 2. Using both anion exchange and cation exchange resins allows for reuse, eliminating the need for specialized resins and reducing costs. Operation is simple, requiring no pH adjustment, simplifying experiments and improving the stability of the experimental procedure.

[0020] 3. Reduce the use of toxic and harmful reagents. This invention does not use acetone, reducing contamination of the laboratory and irritation to laboratory personnel.

[0021] 4. The method of the present invention has a good separation effect of Mn and Mg. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the Ni separation process using a combined resin column in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the first cation exchange resin column rinsing result in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the second combined resin column rinsing result in an embodiment of the present invention. Detailed Implementation

[0025] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0026] Example

[0027] This embodiment uses basalt standard materials BHVO-2 and BIR-1a, and pure olivine standard material JP-1 as experimental subjects, and employs the method of this invention for Ni chemical separation. Specifically, it includes the following steps:

[0028] 1.5 ml of AG50W-X8 (200-400 mesh, Bio-Rad, USA) cation exchange resin was packed into a PP resin column to form a cation exchange resin column (column diameter 0.8 cm, referred to as "Column 1"). The column was then equilibrated by adding 6 ml of 6 mol / L HCl, 10 ml of pure water, and 5 ml of a mixed solution of 0.2 mol / L ammonium citrate and 3 mol / L ammonia. 2 ml of the sample solution was added to the cation exchange resin column; most of the major and trace elements eluted directly. The column was then eluted by adding a mixed solution of 0.2 mol / L ammonium citrate and 3 mol / L ammonia and 0.5 mol / L HCl; residual K, Na, and some ammonium ions were eluted out.

[0029] An anion exchange resin column (referred to as "column 2") is set up below the cation exchange resin column. The column is filled with AG1-X8 (200-400 mesh) anion exchange resin, with a diameter of 0.6 cm and a length of 11 cm. Concentrated hydrochloric acid is added to equilibrate the anion exchange resin column. Column 1 is eluted with 5 ml of 10 mol / L HCl, and the solution flows through column 1 into column 2. Elements such as Ni, Mn, Zn, Co, and Cu are eluted from column 1 by concentrated HCl. Mn, Zn, Co, and Cu form anionic complexes in concentrated hydrochloric acid, enter column 2, and adsorb onto the anion exchange resin. Ni does not form anionic complexes in concentrated HCl and flows directly out through column 2, completing the separation of Ni from the matrix elements.

[0030] Reference Figure 1-3 The rock powder sample was dissolved to form a solution in an ammonia-ammonium citrate buffer solution. The sample was added to column 1 and eluted with ammonia-ammonium citrate solution and 0.5 mol / L HCl. Elements K, Na, Al, Ba, Ca, Cd, Cr, Fe, Li, Mg, Mn, Mo, Sr, Ti, V, Ni, Co, Cu, and Zn were separated from each other. Column 1 was then eluted with 10 mol / L HCl, eluting Ni, Co, Cu, and Zn, which flowed directly into column 2. Co, Cu, Zn, and Mn were adsorbed by the anion exchange resin in column 2, while Ni eluted directly.

[0031] After separation, the contents of Mn and Mg were both below the detection limits of inductively coupled plasma atomic absorption spectrometry (Mg < 0.0003 ppm, Mn < 0.00006 ppm). The data are shown in the table below:

[0032] α-Ni 1 Elemental solutions 0.032 0.000 0.000 α-Ni 2 Elemental solutions 0.095 0.000 0.001 JP-1 1 Dunite 0.040 0.000 0.000 JP-1 2 Dunite 0.113 0.000 0.000 BHVO-2 1 Basalt 0.017 0.000 0.000 BHVO-2 2 Basalt 0.062 0.000 0.000 BHVO-2 3 Basalt 0.009 0.000 0.000 BHVO-2 1 repeat Basalt 0.017 0.000 0.000 BIR-1a Basalt 0.026 -0.001 0.000 BIR-1a Basalt 0.030 0.000 0.000 BIR-1a Basalt 0.032 0.000 0.000 <![CDATA[0.2N HNO3]]> Background solution 0.000 0.000 0.000 <![CDATA[0.2N HNO3]]> Background solution 0.000 0.000 0.000

[0033] This invention provides a rapid and efficient chemical separation method for Ni, optimizing the traditional method of at least two (or three in conventional methods) chemical separation into a single-step combined column separation method. This method has good applicability and can be used for the analysis of various lithological samples, including basalt, granite, shale, and carbonate rocks. The Ni elemental separation step uses a combined column to separate Ni from the matrix element in one step, which is more efficient than currently published Ni chemical separation methods. Furthermore, it does not use organic reagents such as acetone, resulting in less environmental pollution and less irritation to laboratory personnel; it also eliminates the need for pH adjustment, simplifying operation. This method reduces experimental time, improves experimental efficiency, and increases the stability of the results.

[0034] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0035] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for the one-step chemical separation of nickel from rock samples using a combined resin column, characterized in that, Includes the following steps: First, the rock sample solution was added to a cation exchange resin column, and the column was eluted sequentially with a mixed solution of 0.2 mol / L ammonium citrate + 3 mol / L ammonia and 0.5 mol / L HCl. Then, an anion exchange resin column was placed below the cation exchange resin column, and the column was eluted with 10 mol / L HCl. The solution passed through the cation exchange resin column and flowed into the anion exchange resin column, while nickel flowed out through the anion exchange resin column.

2. The method for one-time chemical separation of nickel from rock samples using a combined resin column according to claim 1, characterized in that, The cationic resin is AG50W-X8.

3. The method for one-time chemical separation of nickel from rock samples using a combined resin column according to claim 1, characterized in that, The anion exchange resin is AG1-X8.

4. The method for one-time chemical separation of nickel from rock samples using a combined resin column according to claim 1, characterized in that, Specifically, the following steps are included: 1.5 ml of AG50W-X8 cation exchange resin was packed into a PP resin column to form a cation exchange resin column; 6 ml of 6 mol / L HCl, 10 ml of pure water, and 5 ml of a mixed solution of 0.2 mol / L ammonium citrate and 3 mol / L ammonia were added sequentially to equilibrate the cation exchange resin column; 2 ml of sample solution was added to the cation exchange resin column, and then the cation exchange resin column was rinsed sequentially with a mixed solution of 0.2 mol / L ammonium citrate and 3 mol / L ammonia and 0.5 mol / L HCl. An anion exchange resin column was set up below the cation exchange resin column. The anion exchange resin column was filled with AG1-X8 anion exchange resin, and 10 ml of 10 mol / L HCl was added to rinse the anion exchange resin column. Then, 5 ml of 10 mol / L HCl was used to rinse the cation exchange resin column. The solution passed through the cation exchange resin column and flowed into the anion exchange resin column. Nickel flowed directly out through the anion exchange resin column, thus completing the separation of nickel from the matrix element.

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