A method for combined analysis of iron-55 and nickel-63 in urine samples

Abstract

This invention relates to a combined analytical method for iron-55 and nickel-63 in urine samples, which involves adding concentrated hydrochloric acid and Fe... 3+ Ni 2+ The urine sample underwent pretreatment with hydrogen peroxide, followed by oxidation with hydrogen peroxide and co-precipitation with sodium hydroxide. The sample was then purified by separation and purification using anion exchange resin combined with dimethylglyoxime precipitation. 55 Fe and 63 Ni, after purification 55 Fe and 63 Ni was measured using a liquid scintillation counter. The method of this invention was applied to a set of eight urine samples. 55 Fe、 63 The radiochemical separation process for Ni requires only 5 hours, making it a rapid and accurate combined measurement method that can simultaneously achieve... 55 Fe and 63 The detection of two radioactive elements, Ni, overcomes the limitations of existing technologies for measuring nitrogen in urine samples. 55 The Fe method is time-consuming and cannot measure simultaneously. 55 Fe and 63 Ni deficiency.

Description

Technical Field

[0001] This invention relates to the field of radioactive element detection and analysis technology, and in particular to a combined analytical method for iron-55 and nickel-63 in urine samples. Background Technology

[0002] Radioactive iron-55 ( 55 Fe) and radioactive nickel-63 ( 63 Ni is a common radioactive isotope in nuclear facilities, and its production process is mainly related to neutron activation. In nuclear facilities, structural materials (such as pipes and pressure vessels) are usually made of alloys containing iron and nickel. When the reactor is running, neutrons in the reactor interact with these structural materials. 55 Fe is produced by neutron irradiation of two stable isotopes of iron: 54 Fe(n,γ) 55 Fe and 56 Fe(n,2n) 55 Fe, 63 Ni is produced by neutron irradiation of nickel and copper: 62 Ni(n,γ) 63 Nihe 63 Cu(n,P) 63 Ni. 55 Fe and 63 Ni has a long half-life of 2.7 years and 100.1 years, respectively, which means that it can exist in the environment for a long time.

[0003] During overhauls and decommissioning of nuclear facilities, activated metals can corrode into the coolant and potentially enter the human body through various routes (e.g., inhalation, ingestion, or wounds). Once inside the body, radioactive material continuously releases radiation, which can cause cell damage, increase the risk of cancer, and other health problems. Internal radiation is a particular concern for nuclear workers who are exposed to low levels of radioactivity for extended periods. 55 Fe and 63 Ni primarily emits beta particles, and although their beta radiation energy is relatively low, the long-term cumulative effect is still significant.

[0004] In order to assess whether nuclear practitioners are subject to 55 Fe and 63 Internal irradiation with Ni and estimation of its effective dose require the determination of biological samples. Commonly used biomonitoring methods include analyzing the radioactivity concentration in urine, feces, or blood. Among these, urine is the most convenient sample type to collect.

[0005] Determining radioactive iron-55 and nickel-63 in urine samples is a complex process, primarily due to the low concentrations of these isotopes and the complexity of the urine matrix. Currently, only a few methods have been reported for application in urine samples. 55 Fe, for urine 63 Measurements of nitrogen (Ni) are rarely reported. To pre-concentrate iron from a urine matrix, a large volume of sample needs to be evaporated to near-dryness, followed by ashing of the residue. Iron is then extracted using multiple ferric hydroxide precipitation, solvent extraction, and extraction chromatography. Multiple ferric hydroxide precipitation utilizes the characteristic of iron ions forming ferric hydroxide precipitates under alkaline conditions. By adjusting the pH of the solution, iron ions combine with hydroxide ions to form insoluble ferric hydroxide precipitates, thus separating iron from the complex urine matrix. Solvent extraction is based on the complexation between iron ions and specific organic extractants, transferring iron from the aqueous phase to the organic phase for separation. Extraction chromatography utilizes the selective interaction between functional groups on the stationary phase and the target element to effectively separate the target element from other impurities.

[0006] While the methods described above typically achieve high iron recovery rates, these processes are extremely time-consuming, with radiochemical separation procedures often exceeding two days. Therefore, there is an urgent need for a method that is easy to operate, less time-consuming, and capable of simultaneously separating, purifying, and accurately detecting iron in urine samples. 55 Fe and 63 Ni's method. Summary of the Invention

[0007] This invention discloses a combined analytical method for iron-55 and nickel-63 in urine samples, aiming to solve the problems in existing technologies for the analysis of iron-55 and nickel-63 in urine samples. 55 Fe and 63 The present invention addresses the technical problems of complex operation and long detection time in Ni detection methods. It establishes a method for detecting Ni in urine samples... 55 Fe and 63 The combined method for Ni measurement involves treating urine samples with hydrogen peroxide oxidation, co-precipitating with sodium hydroxide, and then separating and purifying the sample using anion exchange resin combined with dimethylglyoxime precipitation. 55 Fe and 63 Ni, after purification 55 Fe and 63 Ni was measured using a liquid scintillation counter (LSC).

[0008] The present invention adopts the following technical solution:

[0009] This invention provides a method for the combined analysis of iron-55 and nickel-63 in urine samples, comprising the following steps:

[0010] S1: Urine sample pretreatment

[0011] Add concentrated hydrochloric acid and Fe to the urine sample 3+ Ni 2+ After heating with hydrogen peroxide, the pH was adjusted to alkaline with solid sodium hydroxide. After stirring, the sample was centrifuged, the supernatant was discarded, the precipitate was washed, and then dissolved with concentrated hydrochloric acid to obtain the sample solution.

[0012] S2: Radiochemical separation of the sample

[0013] The resin column is packed with anion exchange resin and pretreated with hydrochloric acid before use.

[0014] The sample solution was passed through an anion exchange resin, the effluent was collected and labeled as the Ni component;

[0015] The anion exchange resin was eluted sequentially with 12 mol / L HCl and 6 mol / L HCl. After elution, the anion exchange resin was eluted with 0.1 mol / L HCl. The eluent was labeled as follows: 55 Fe test solution, measuring iron recovery rate and 55 Fe activity;

[0016] S3: Separation and Measurement of Ni Components

[0017] Add citric acid and dimethyl oxime ethanol solution to the effluent, adjust the pH to alkaline with ammonia water to form a precipitate, centrifuge, discard the supernatant, wash the precipitate, dissolve it with concentrated hydrochloric acid, centrifuge, discard trace amounts of insoluble matter, retain the supernatant and label it as such. 63 Ni test solution, measuring nickel recovery rate and 63 Ni activity.

[0018] Preferably, in step S1, 5‰–5% (v / v) of 12 mol / L concentrated hydrochloric acid and 2–10 mg of Fe are added to the urine sample. 3+ 2-5mg Ni 2+ And 1‰ to 1% (v / v) of 30% hydrogen peroxide.

[0019] Preferably, in step S1, the heating temperature is 70–120°C and the time is 8–12 min; the pH is adjusted to 8–10 with sodium hydroxide solid, and after stirring for 10–30 min, centrifugation is performed.

[0020] Preferably, in step S1, after dissolving in 12 mol / L concentrated hydrochloric acid, the system is adjusted to 9 mol / L HCl with high-purity water.

[0021] More preferably, in step S1, the precipitate is washed with high-purity water.

[0022] For the detection of radioactive iron-55 and radioactive nickel-63, urine, the most convenient sample to collect, is selected. However, urine contains water, electrolytes, organic acids and alkalis, proteins, sugars, and amino acids, resulting in a complex matrix composition. This complex matrix can cause a matrix effect on the separation and measurement of radioactive isotopes; that is, other components in the urine can affect the extraction efficiency, recovery rate, and measurement accuracy of the target element. This is the difficulty in using urine as a sample for radioactive element detection. To address these issues, this invention designs a specific urine sample pretreatment process, adding concentrated hydrochloric acid and Fe... 3+ Ni 2+ The addition of hydrogen peroxide and a heating process can significantly improve the extraction and separation efficiency of target elements. Concentrated hydrochloric acid (HCl) is a strong acid that effectively breaks down the complex matrix of urine samples, such as proteins, organic matter, and other interfering substances. By lowering the pH of the solution, concentrated hydrochloric acid can release metal ions from their bound state into a free state, making them easier to capture in subsequent separation and enrichment processes. Hydrogen peroxide is a strong oxidant that can oxidize organic matter in urine samples, further breaking down the complex organic matrix and reducing the adsorption and encapsulation of metal ions by organic matter. Furthermore, hydrogen peroxide can oxidize some low-valence metal ions, making them more readily react with acids, thereby increasing the solubility of metal ions. During the heating process, the chemical reaction is accelerated. Subsequent adjustment of the pH to alkaline (pH 8-10) with solid sodium hydroxide yields ferric hydroxide and nickel hydroxide precipitates, promoting the precipitation of target metal ions. This invention, by adding concentrated hydrochloric acid and Fe... 3+ Ni 2+ Together with hydrogen peroxide, it can simultaneously achieve multiple functions such as matrix destruction, metal ion release, and precipitation formation, simplifying the pretreatment steps and reducing operation time.

[0023] Preferably, in step S2, the anion exchange resin is packed into a 2 mL resin column, pretreated with 9 mol / L HCl, and then ready for use.

[0024] Preferably, in step S2, the sample solution is passed through the anion exchange resin column at a flow rate of 0.5 to 3 mL / min.

[0025] Preferably, in step S2, the anion exchange resin column is eluted with 20-40 column volumes of 12 mol / L HCl at a flow rate of (0.5-3) mL / min and 3-5 column volumes of 6 mol / L HCl at a flow rate of (0.5-3) mL / min, respectively. After elution, Fe is eluted with 1-3 column volumes of 0.1 mol / L HCl at a flow rate of (0.5-3) mL / min.

[0026] Preferably, in step S2, the method for measuring the iron recovery rate is one of inductively coupled plasma atomic emission spectrometry, ultraviolet spectrophotometer or X-ray fluorescence spectrometer. 55 The method for measuring Fe activity is a liquid scintillation counter.

[0027] More preferably, in step S2, the anion exchange resin is a strongly basic anion exchange resin, specifically AGMP-1 anion exchange resin.

[0028] After urine sample pretreatment, almost all the target metal ions to be detected are enriched, resulting in a sample solution that facilitates subsequent separation. This invention utilizes anion exchange resin to separate iron-55 and nickel-63 in the sample solution, achieving effective separation of these two radioactive elements. Anion exchange resins exhibit high selectivity for metal ions, effectively separating Fe... 3+ and Ni 2+ Separate, especially for 55 Fe and 63 For the two radioactive isotopes Ni, anion exchange resins can achieve highly selective capture and elution, ensuring the effective separation of the target element from other impurities. After separation by anion exchange resins... 55 Fe remains in the anion exchange resin. 63 Ni is present in the effluent, thus achieving... 55 Fe and 63 Effective separation of Ni. Targeting the residue remaining in the anion exchange resin. 55 In this invention, Fe is obtained by eluting with hydrochloric acid of different concentrations (12 mol / L and 6 mol / L) and then eluting with 0.1 mol / L hydrochloric acid, resulting in a high-purity Fe. 55 The Fe test solution, when used for subsequent detection, yields more accurate results. The process involves eluting with two different concentrations of hydrochloric acid to elute potentially interfering metal ions in stages, removing any remaining ions from the resin column that could affect the results. 55 For Fe measurement of interfering nuclides, a multi-step elution strategy not only improved separation efficiency but also ensured high recovery rates. After elution, the purified nuclides were purified using low-concentration hydrochloric acid. 55 Fe was desorbed from the resin column, and the elution yielded... 55 Fe test solution can be used to measure iron recovery rate and radioactive elements. 55 Fe activity.

[0029] Preferably, in step S3, 0.2 mL of 2% (w / v) citric acid and 2-5 mL of 1% (w / v) dimethyl diketone oxime ethanol solution are added to the effluent, and ammonia is added to adjust the pH to 8-10.

[0030] Preferably, in step S3, the method for measuring the nickel recovery rate is one of inductively coupled plasma atomic emission spectrometry, ultraviolet spectrophotometry, or X-ray fluorescence spectrometry. 63 The method for measuring Ni activity is a liquid scintillation counter.

[0031] Currently, existing technologies for radioactive elements 63 There are few methods for detecting Ni. Therefore, this invention addresses this issue by obtaining Ni through rinsing anion exchange resin. 55 After testing the Fe test solution for recovery and activity, post-treatment was also performed on the effluent containing a large proportion of nickel. This invention involves adding citric acid and dimethylglyoxime ethanol solution to the effluent to form a Ni precipitate, followed by acid dissolution and centrifugation, and finally determining the Ni content. 63 The recovery rate and activity of Ni. After adding citric acid and dimethyl oxime ethanol solution, other interfering ions combine with citrate ions to form stable soluble complexes, thus improving Ni recovery. 2+ It rapidly forms an insoluble complex precipitate with dimethylglyoxime; this process is very rapid, typically completed within minutes. This invention significantly shortens the separation time while removing potential interfering nuclides during measurement. Compared to traditional extraction and column separation methods… 63 The purification method for Ni can achieve more efficient precipitation by using dimethylglyoxime, reducing the number of operation steps and time costs.

[0032] The technical solution adopted in this invention can achieve the following beneficial effects:

[0033] (1) This invention involves adding concentrated hydrochloric acid and Fe to a urine sample. 3+ Ni 2+ The mixture of hydrogen peroxide and heat treatment rapidly breaks down the complex matrix of the urine sample, making it easier to extract metal ions. Subsequently, the pH is adjusted to alkaline using solid sodium hydroxide, forming a precipitate, which greatly simplifies the pretreatment steps.

[0034] (2) The application of anion exchange resin columns in this invention makes the separation of Fe and Ni more efficient, mainly because Fe 3+ It can form anionic complexes under high-concentration hydrochloric acid conditions, which are then adsorbed by anion exchange resins, while Ni 2+ Therefore, it will not form anionic complexes and cannot be adsorbed by anion exchange resin. Thus, the sample can be passed through the anion exchange resin... 55 Fe and 63 Ni is effectively separated. Specifically, this invention uses two different concentrations of hydrochloric acid to first rinse the anion exchange resin adsorbed with Fe components. This is mainly because during internal irradiation at nuclear power plants, other radioactive nuclides (such as those associated with...) may be present in the urine. 55 Fe homologous radionuclides60 Co、 137 Cs, etc., in order to remove these effects 55 For Fe liquid scintillation measurements of potential radionuclides, the resin column needs to be eluted with hydrochloric acid of different concentrations to allow interfering nuclides to dissociate into the elution solution first. Then, the Fe component in the anion exchange resin is eluted with low-concentration hydrochloric acid to ensure that the Fe component obtained by elution has high purity and improves the detection accuracy.

[0035] (3) In the separation and treatment of Ni component, the present invention adds citric acid and dimethylglyoxime ethanol solution, utilizes citric acid to form a stable soluble complex with other interfering elements to reduce the influence of interfering elements on the activity test of Ni component, utilizes dimethylglyoxime to form a stable precipitated complex with Ni, and finally uses centrifugation to separate the soluble complex and the precipitated complex, thereby realizing the purification of Ni in the effluent and improving the selectivity and recovery rate of Ni.

[0036] (4) The present invention has carefully designed all steps from urine sample pretreatment to final radioactivity measurement, reducing complex manual operations, reducing human error, and ensuring the reproducibility and reliability of the results.

[0037] (5) The present invention uses multiple methods (such as inductively coupled plasma atomic emission spectrometer, ultraviolet spectrophotometer, X-ray fluorescence spectrometer, liquid scintillation counter, etc.) for cross-validation to ensure the reliability and accuracy of the data.

[0038] (6) The method of the present invention is used to analyze a group of 8 urine samples. 55 Fe、 63 The radiochemical separation process for Ni takes only 5 hours, making it a rapid and accurate method for combined measurement. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, forming part of the present invention. The illustrative embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 This is a process flow diagram of the present invention;

[0041] Figure 2 for 55 LSC measurement spectrum of Fe;

[0042] Figure 3 for 63 LSC measurement spectrum of Ni. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of this invention, it should be noted that the term "or" is generally used to include the meaning of "and / or," unless otherwise expressly stated. The described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0044] To address the problems existing in the prior art, this invention provides a combined analytical method for iron-55 and nickel-63 in urine samples. The urine sample is treated with hydrogen peroxide oxidation, co-precipitated with sodium hydroxide, and then purified by anion exchange resin combined with dimethylglyoxime precipitation. 55 Fe and 63 Ni, after purification 55 Fe and 63 Ni is measured using a liquid scintillation counter (LSC). This method can simultaneously measure the concentration of ni in a single urine sample. 55 Fe、 63 Ni, a radioactive nuclide, can complete the analysis of a set of 8 samples within 5 hours. 55 Fe and 63 The Ni radiochemical separation process greatly improves sample processing efficiency and reduces the time required for sample radiochemical separation.

[0045] Example 1

[0046] Add to 200 mL of urine sample respectively 55 Fe standard solution 39.6 Bq, 63 Using 35.3 Bq of Ni standard solution and urine as the test solution, the sample was pretreated and subjected to radiochemical separation using the method of this invention. The separated sample... 55 Fe and 63 Ni was measured using LSC, and the verification method was applied to urine samples. 55 Fe and 63 Separation effect of Ni, detection limit and recovery rate.

[0047] like Figure 1 As shown, a combined analytical method for iron-55 and nickel-63 in urine samples includes the following steps:

[0048] S1: Pre-processing of urine samples

[0049] Add 2 mL of 12 mol / L concentrated hydrochloric acid and 5 mg of Fe to 200 mL of urine sample. 3+ and 2mg Ni 2+Add 0.2 mL of 30% H2O2, heat at 100℃ for 10 min, add sodium hydroxide (NaOH) solid particles to adjust the sample pH to 8-10, stir for 20 min to generate Fe(OH)3-Ni(OH)2 coprecipitate, centrifuge, discard the supernatant, wash the precipitate with high-purity water, dissolve it with 10.0 mL of 12 mol / L HCl, add high-purity water to the total volume to 13.3 mL, adjust the system to 9 mol / L HCl, and label it as sample solution.

[0050] S2: Radiochemical separation and measurement of samples

[0051] A 2 mL resin column was packed with AGMP-1 anion exchange resin and pretreated with 9 mol / L HCl before use.

[0052] The sample solution was passed through an AGMP-1 anion exchange resin column at a flow rate of 2 mL / min. The effluent was collected and labeled as the Ni component. The anion exchange resin column was then eluted with 60 mL of 12 mol / L HCl at a flow rate of 2 mL / min and 8 mL of 6 mol / L HCl at a flow rate of 1 mL / min. After elution, Fe was eluted with 3 mL of 0.1 mol / L HCl at a flow rate of 2 mL / min. The retained eluent was labeled as... 55 The Fe test solution was analyzed using X-ray fluorescence spectrometry (XRF) to measure iron recovery, and liquid scintillation counter (LSC) was used to measure... 55 Fe activity.

[0053] S3: Separation and Measurement of Ni Components

[0054] Add 0.2 mL of 2% (w / v) citric acid and 2.5 mL of 1% (w / v) dimethyl diketone oxime (DMG) ethanol solution to the Ni fraction. Adjust the pH to 8-10 with ammonia. A bright red DMG-Ni precipitate forms. Centrifuge, discard the supernatant, wash the precipitate with high-purity water, add 0.3 mL of 12 mol / L HCl, let stand for 10 min, centrifuge, discard trace amounts of insoluble matter, and retain the supernatant, labeled as... 63 The nickel recovery rate of the Ni test solution was measured using XRF and LSC. 63 Ni activity.

[0055] S4: Measurement Results

[0056] The method described in this embodiment is used to separate and purify urine samples. 55 Fe and 63 The recovery rate (R) and limit of detection (MDC) of Ni are shown in Table 1. MDC is calculated using formula (1):

[0057]

[0058] In the formula, k is the coverage factor, with a value of 1.645 (confidence level of 95%); B is the LSC measurement value of the blank sample in... 55 Fe or 63 Ni is the count corresponding to the energy range; ε is the LSC measurement efficiency; R is the recovery rate of iron or nickel; t is the measurement time; v is the sample volume.

[0059] Using the internal radiation dose calculation software GenmodPC, simulations were performed to determine the effective dose to be accumulated in an emergency scenario when the effective dose is 1 mSv. 55 After inhalation of Fe, the urine concentration was 21 Bq / g after 2 days and 3.62 Bq / g after 1 month; for 63 Ni inhalation resulted in a urine level of 7937 Bq / L after 2 days and 298 Bq / L after 1 month.

[0060] The combined process analysis method of this invention has a detection limit that meets the requirements of detecting certain substances in human urine under emergency conditions. 55 Fe and 63 Ni measurement requirements. 55 Fe and 63 The LSC measurement spectrum of Ni is as follows: Figure 2 , Figure 3 As shown in the spectrum, after the joint separation process, 55 Fe and 63 Ni achieved excellent separation results.

[0061] Table 1 55 Fe and 63 Ni recovery rate and lowest detection limit

[0062] Nuclide R(％) MDC(Bq / L) <![CDATA[ 55 Fe]]> 98.3 1.5 <![CDATA[ 63 In]]> 73.5 0.5

[0063] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for the combined analysis of iron-55, nickel-63 in urine samples, characterized in that, The method comprises the following steps: S1: pretreatment of urine sample In the urine sample, concentrated hydrochloric acid, Fe 3+ , Ni 2+ and hydrogen peroxide are added, heated, and then the pH is adjusted to be alkaline with sodium hydroxide solid. After stirring, the sample is centrifuged, the supernatant is discarded, and the precipitate is washed. After being dissolved with concentrated hydrochloric acid, a sample solution is obtained. S2: radiochemical separation of sample The resin column is filled with anion exchange resin and pretreated with hydrochloric acid and then used; The sample solution is passed through the anion exchange resin, and the effluent is collected and marked as Ni component; The anion exchange resin is sequentially eluted with 12 mol / L HC1 and 6 mol / L HC1, and after elution, the anion exchange resin is eluted with 0.1 mol / L HC1, and the eluate is marked as 55 Fe test solution, the recovery rate of iron is measured and 55 Fe activity; S3: separation and measurement of Ni component To the effluent was added citric acid and dimethylglyoxime in ethanol, and the pH was adjusted to basic with ammonia, resulting in a precipitate. The precipitate was centrifuged, the supernatant was discarded, and the precipitate was washed. The precipitate was dissolved in concentrated hydrochloric acid, centrifuged, and the trace insoluble material was discarded. The supernatant was retained and labeled as 63 Ni, the nickel recovery was measured and 63 Ni activity; In step S1, 5 ‰ to 5% v / v of 12 mol / L concentrated hydrochloric acid, 2 to 10 mg of Fe 3+ , 2 to 5 mg of Ni 2+ and 1 ‰ to 1% v / v of 30% hydrogen peroxide are added to the urine sample. In step S3, 0.2 mL of 2% w / v citric acid and 2-5 mL of 1% w / v dimethylglyoxime ethanol solution are added to the effluent, and the pH is adjusted to 8-10 with ammonia water.

2. The method for combined analysis of Fe-55, Ni-63 in urine sample according to claim 1, characterized in that, In step S1, the heating temperature is 70-120°C, and the time is 8-12 min; the pH is adjusted to 8-10 with sodium hydroxide solid, and after stirring for 10-30 min, centrifugation is performed.

3. The method for combined analysis of Fe-55, Ni-63 in urine sample according to claim 1, characterized in that, In step S1, after dissolving with 12 mol / L concentrated hydrochloric acid, the system is adjusted to 9 mol / L HCl with high-purity water.

4. The method for combined analysis of Fe-55 and Ni-63 in urine sample according to claim 1, characterized in that, In step S2, the anion exchange resin is packed into a 2 mL resin column and pretreated with 9 mol / L HCl and then used.

5. The method for combined analysis of Fe-55, Ni-63 in urine sample according to claim 1, characterized in that, In step S2, the sample solution is passed through the anion exchange resin column at a flow rate of 0.5-3 mL / min.

6. The method for combined analysis of Fe-55, Ni-63 in urine sample according to claim 1, characterized in that, In step S2, the anion exchange resin column is eluted with 20-40 column volumes of 12 mol / L HCl at a flow rate of (0.5-3) mL / min and 3-5 column volumes of 6 mol / L HCl at a flow rate of (0.5-3) mL / min, and after elution, 1-3 column volumes of 0.1 mol / L HCl are eluted at a flow rate of (0.5-3) mL / min.

7. The method for combined analysis of Fe-55, Ni-63 in urine sample according to claim 1, characterized in that, The method for measuring the iron recovery rate in step S2 is one of an inductively coupled plasma atomic emission spectrometer, an ultraviolet spectrophotometer or an X-ray fluorescence spectrometer. 55 The method for measuring the Fe activity is a liquid scintillation counter.

8. The method for combined analysis of Fe-55, Ni-63 in urine sample according to claim 1, characterized in that, In step S3, the method for measuring the nickel recovery rate is one of inductively coupled plasma atomic emission spectrometry, ultraviolet spectrophotometry, or X-ray fluorescence spectrometry. 63 The method of measuring the Ni activity is liquid scintillation counting.

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