Niobium-94 analysis method and niobium-94 analysis system

Abstract

To provide a niobium-94 analysis method which enables simple and accurate analysis of niobium-94.SOLUTION: A niobium-94 analysis method is provided, comprising introducing a sample solution to a column filled with silica gel to adsorb niobium-94 (94Nb) contained in the sample solution to the column, isolating niobium-94 in the column using eluent and eluting the niobium-94 from the column, and measuring the eluate from the column using an inductively coupled plasma mass spectrometer to qualitatively and / or quantitatively determine niobium-94.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for analyzing niobium-94 and a system for analyzing niobium-94. In particular, the present invention relates to an analysis method and an analysis system that enable the analysis of niobium-94 using an inductively coupled plasma mass spectrometer.

Background Art

[0002] Since radioactive isotopes have potential risks to human health and the environment depending on their concentration, it is important to grasp their radiation dose and radioactivity and estimate the potential impact on people and the environment. The quantification of radioactive isotopes mainly relies on radiation measurement methods. However, when the target analyte is present in trace amounts, there is a drawback that the analysis is interfered by various other substances contained in environmental samples such as soil, seawater, and seafloor soil. An inductively coupled plasma mass spectrometer can quickly quantify by ionizing a sample in a plasma and separating and detecting the ionized target analyte for each mass-to-charge ratio. However, when isobars are present, the target substance and the isobar are detected simultaneously, so it is necessary to separate them before they reach the detector.

[0003] Among radioactive isotopes, niobium-94 ( 94 Nb) needs to be monitored because it has a long half-life of 20,300 years. However, in the radiation measurement commonly used for measuring radioactive isotopes, it is known that cobalt-60 ( 60 Co), etc. 94 interferes with the measurement of 94 Nb. Also, in mass spectrometry, zirconium-94 ( 94 Zr) with a natural isotope ratio of 17.4% and molybdenum-94 ( 94 Mo) with a natural isotope ratio of 9.2%, etc. 94 are known to interfere with the measurement because they are isobaric with 94 Nb. Therefore, the isolation of 94There is a demand for constructing a multi-analyte analysis system capable of separating Nb with high efficiency.

[0004] Therefore, techniques for separating radioactive niobium from thermally neutron-irradiated zirconium wires and uranium fission products from radioactive zirconium have been studied (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the method shown in Non-Patent Document 1 is analyzed by radiation measurement and is not analyzed by a mass spectrometer, which has many advantages such as 1) being able to be miniaturized, 2) being able to perform high-speed scanning, 3) being relatively inexpensive, 4) not requiring qualification for handling radioactive substances, and 5) being easy to operate. Also, in the method shown in Non-Patent Document 1, 94 Mo, which has the same weight relationship as Nb as a mixed nuclide in the sample, 94 is not included, and it has not been confirmed whether the separation of niobium and molybdenum has been achieved. Furthermore, the method shown in Non-Patent Document 1 has a niobium recovery rate of about 80% and is not an automatic analysis system, so there is still room for improvement from the perspective of multi-analyte analysis.

[0007] An object of the present invention is to provide a method and a system for analyzing niobium-94 that can analyze niobium-94 simply and with high precision.

Means for Solving the Problems

[0008] As a result of intensive studies by the present inventors to solve the above problems, it has been found that the above problems can be solved by pretreating using a column filled with silica gel by a predetermined method and applying the measurement technique of an inductively coupled plasma mass spectrometer, and the present invention has been completed. That is, the present invention is as follows.

[0009] (1) A step of introducing a sample solution into a column filled with silica gel and adsorbing niobium 94 ( 94 Nb) contained in the sample solution to the column; A step of separating niobium 94 with the column using an eluent and eluting niobium 94 from the column; A step of measuring the eluate from the column with an inductively coupled plasma mass spectrometer to qualitatively and / or quantitatively analyze niobium 94, and an analysis method for niobium 94. An analysis method for niobium 94. (2) The analysis method for niobium 94 according to (1), wherein the aqueous solution for preparing the sample solution is an acidic aqueous solution containing at least one of an aqueous hydrochloric acid solution and an aqueous nitric acid solution. (3) The analysis method for niobium 94 according to (1) or (2), wherein the aqueous solution for preparing the sample solution is an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 0.5 mol / L to 7 mol / L. (4) The sample solution contains niobium 94, zirconium 94 ( 94 Zr), and molybdenum 94 ( 94 Mo), and the analysis method for niobium 94 according to any one of (1) to (3). (5) The analysis method for niobium 94 according to any one of (1) to (4), wherein the eluent is an aqueous oxalic acid solution having an oxalic acid concentration of 0.01 mol / L or more. (6) After the adsorbing step and before the eluting step, the method further includes a step of washing the column on which niobium 94 is adsorbed with a washing solution, The analysis method for niobium 94 according to any one of (1) to (5), wherein the washing solution is an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 0.5 mol / L to 7 mol / L. The method for analyzing niobium 94 according to any one of (1) to (6), wherein the average pore diameter of the silica gel is 10 nm to 50 nm. (8) The method for analyzing niobium 94 according to any one of (1) to (7), wherein in the step of qualitative and / or quantitative analysis, a reaction gas containing ammonia is introduced into the inductively coupled plasma mass spectrometer together with the eluate from the column, and an ammonia adduct of niobium 94 is detected. (9) An analysis system for niobium 94 used in the method for analyzing niobium 94 ( 94 Nb), comprising: a column filled with silica gel; a solution supply device for supplying a plurality of types of solutions; a sample injection device for preparing a sample solution by injecting a sample containing niobium 94 into an aqueous solution for preparing the sample solution supplied from the solution supply device; a flow path switching device for switching the flow path so as to introduce a plurality of types of solutions supplied from the solution supply device into the column in a predetermined flow rate and order; an inductively coupled plasma mass spectrometer for analyzing the niobium 94. introducing a sample solution into a column filled with silica gel, adsorbing niobium 94 contained in the sample solution on the column; supplying a cleaning solution to the column on which the niobium 94 is adsorbed, and cleaning the column; supplying an eluent to the column after cleaning, separating niobium 94, and eluting niobium 94 from the column; measuring the eluate from the column with an inductively coupled plasma mass spectrometer to qualitatively and / or quantitatively analyze niobium 94. An analysis system for niobium 94. (10) The aqueous solution for preparing the sample solution is an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 0.5 mol / L to 7 mol / L. The cleaning solution is an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 0.5 mol / L to 7 mol / L. The eluent is an aqueous oxalic acid solution having an oxalic acid concentration of 0.01 mol / L or more. The niobium-94 analysis system according to (9), wherein the average pore diameter of the silica gel is 10 nm to 50 nm. (11) The inductively coupled plasma mass spectrometer includes a front quadrupole set to a mass-to-charge ratio (m / z) of 94, which is the mass number of niobium-94, a rear quadrupole set to a mass-to-charge ratio (m / z) of 175, which is the mass number of the ammonia adduct of niobium-94, and a collision / reaction cell disposed between the front quadrupole and the rear quadrupole. The niobium-94 analysis system according to (9) or (10).

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a method and a system for analyzing niobium-94 that can analyze niobium-94 simply and with high accuracy.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7A

Figure 7B

Figure 7C

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0012] Hereinafter, with reference to the drawings, the analysis method and analysis system of the present invention will be described. Note that the embodiments of the present invention described below show an example when embodying the present invention, and do not limit the scope of the present invention to the scope of the description of the embodiments. Therefore, the present invention can be implemented with various modifications to the embodiments.

[0013] One of the features of the present invention is "separation of Nb and its isomers by a column filled with silica gel" 94 "and qualitative analysis and / or quantitative analysis of Nb by an inductively coupled plasma mass spectrometer". 94 It lies in the combination of these.

[0014] (1) Separation of Nb and its isomers by a column filled with silica gel 94 Separation of Nb and its isomers 94 A predetermined sample solution containing Nb is introduced into a column filled with silica gel, and 94 Nb is selectively adsorbed on the column. By eluting the Nb adsorbed on the column with a predetermined eluent, 94 an eluate of purified Nb is obtained. This eluate 94 almost does not contain Nb isomers, 94 and separation of Nb and its isomers is achieved. 94 (2) Qualitative analysis and / or quantitative analysis of Nb by an inductively coupled plasma mass spectrometer 94 Qualitative analysis and / or quantitative analysis of Nb ​As described above, inductively coupled plasma mass spectrometers have many advantages, such as 1) being miniaturizable, 2) enabling high-speed scanning, 3) being relatively inexpensive, 4) not requiring the acquisition of radioactive material handling qualifications, and 5) being easy to operate. However, inductively coupled plasma mass spectrometers have limitations in mass resolution. They can separate and detect ions with a mass difference of one, but cannot separate and detect ions of the same isotope. Before introducing the inductively coupled plasma mass spectrometer, the inventors achieved the separation of Nb from its isotopes by the method described in (1) above. 94 Therefore, for the first time, qualitative and / or quantitative analysis of Nb using a mass spectrometer was achieved. Furthermore, in order to achieve better separation from isotopes, the inventors introduced ammonia gas into the collision / reaction cell of the inductively coupled plasma mass spectrometer and, due to the difference in reactivity of ammonia with radioactive isotopes, 94 achieved the separation of Nb from its isotopes. As a result, not only the separation of Nb from its isotopes before introducing the inductively coupled plasma mass spectrometer by the method described in (1) above, but also 94 after introducing the inductively coupled plasma mass spectrometer, it became possible to separate Nb from its isotopes, and for the first time, qualitative and / or quantitative analysis of Nb using a mass spectrometer with even further removal of isotope interference was achieved. 94 One example of the analysis method of the present invention having the above characteristics is to introduce a sample solution into a column filled with silica gel, and adsorb 94 Nb contained in the sample solution onto the column, separate 94 Nb using an eluent from the column, elute

[0015] Nb from the column, and measure the eluate from the column using an inductively coupled plasma mass spectrometer to qualitatively and / or quantitatively analyze 94 Nb. Optionally, after the adsorption step and before the elution step, the column adsorbed with niobium 94 is further washed with a cleaning solution. These steps can be automatically analyzed by using the on-line solid-phase extraction method and setting a predetermined program. 94 Nb, elute 94 Nb from the column, and measure the eluate from the column using an inductively coupled plasma mass spectrometer to qualitatively and / or quantitatively analyze 94 Nb. These steps include the steps of adsorbing Nb, separating Nb, eluting Nb, and qualitatively and / or quantitatively analyzing Nb. Optionally, after the adsorption step and before the elution step, a step of washing the column adsorbed with niobium 94 with a cleaning solution is further included. These steps can use the on-line solid-phase extraction method and perform automatic analysis by setting a predetermined program.

[0016] The analytical method and system of the present invention utilize a known inductively coupled plasma mass spectrometer to measure the concentration of 94 All that is required is a column packed with silica gel for adsorbing Nb; it does not require advanced measurement skills, is simple and highly accurate, and furthermore, it is possible to perform automatic analysis. The analysis system and analysis method according to this embodiment will be specifically described below.

[0017] (Analysis System) FIG. 1 is a diagram illustrating an example of a schematic configuration of an analysis system. The analysis system 10 shown in FIG. 1 includes, as its main components, a solution supplying device 1, a sample injecting device 2, a column 3, and an inductively coupled plasma mass spectrometry device 4.

[0018] The solution supplying device 1 supplies a plurality of types of solutions to the analysis system 10. The solution supplying device 1 may be a commercially available liquid delivery pump or the like. The sample injection device 2 prepares a sample solution by injecting a sample containing niobium 94, which is an analytical target substance, into a predetermined solution supplied from the solution supply device 1. Alternatively, a sample prepared in advance is stored in a vial or the like, and the sample injection device 2 injects the stored sample. The sample injection device 2 may be a commercially available autosampler or the like. The sample injection device 2 may be installed upstream of the solution supply device 1 as shown in FIG. 1, or may be installed in the middle of the flow path between the solution supply device 1 and the column 3. Column 3 is 94 Adsorbs and desorbs Nb, 94 The column 3 is used to separate and purify Nb. The column 3 may be a commercially available column, filter, cartridge, or the like. It is preferable that the liquid-contacting parts of the solution supplying device 1, the sample injecting device 2, and the column 3 are made of a material that does not contain metal, and that the material is preferably a resin such as polyether ether ketone (PEEK).

[0019] The inductively coupled plasma mass spectrometer 4 can use, for example, a commercially available tandem quadrupole inductively coupled plasma mass spectrometer (ICP-MS / MS) as shown in FIG. 1. The inductively coupled plasma mass spectrometer 4 includes a front-stage quadrupole 41 (hereinafter also referred to as Q1) that sets the mass-to-charge ratio (m / z) to a predetermined value, a rear-stage quadrupole 43 (hereinafter also referred to as Q2) that sets the mass-to-charge ratio (m / z) to a predetermined value, a collision / reaction cell 42 disposed between Q1 41 and Q2 43, and a detector 44. Further, the inductively coupled plasma mass spectrometer 4 can also use a commercially available single quadrupole inductively coupled plasma mass spectrometer (ICP-MS) in a form obtained by removing Q1 from the above ICP-MS / MS.

[0020] When using ICP-MS / MS for the inductively coupled plasma mass spectrometer 4, as monitor ions, for example, the mass-to-charge ratio (m / z) of Q1 41 94 can be set to 94, which is the mass number of Nb, and the mass-to-charge ratio (m / z) of Q2 43 can be set to 94. In this case, Q1 41 and Q2 43 allow only elements with a mass number of 94 to pass through and do not allow elements with other mass numbers to pass through. Also, when using ICP-MS for the inductively coupled plasma mass spectrometer 4, as monitor ions, for example, the mass-to-charge ratio (m / z) of Q2 43 94 can be set to 94, which is the mass number of Nb. In this case, Q2 43 allows only elements with a mass number of 94 to pass through and does not allow elements with other mass numbers to pass through.

[0021] When using ICP-MS / MS for the inductively coupled plasma mass spectrometer 4, for example, 94 a reaction gas with high reactivity with Nb and 94 low reactivity with elements other than Nb is preferably supplied to the collision / reaction cell 42. Examples of the reaction gas include ammonia and oxygen. Among these, as the reaction gas, 94From the perspective of reactivity with Nb, ammonia is preferred. That is, the inductively coupled plasma mass spectrometer 4 preferably mass-separates and passes the elements ionized by the plasma through Q1 41, reacts them with ammonia in the collision / reaction cell 42, increases the mass number by the added ammonia portion, mass-separates and passes them through Q2 43, and detects them with the detector 44. In this case, for example, the mass-to-charge ratio (m / z) of Q1 41 is 94 set to 94, which is the mass number of Nb, and the mass-to-charge ratio (m / z) of Q2 43 is 94 set to 175, which is the mass number of the Nb ammonia adduct. Also, when using ICP-MS for the inductively coupled plasma mass spectrometer 4, it is preferable to supply ammonia to the collision / reaction cell 42, react it with ammonia in the collision / reaction cell 42, increase the mass number by the added ammonia portion, set the mass-to-charge ratio (m / z) to 175 in Q2 43 for mass separation and passage, and detect it with the detector 44.

[0022] As described above, an example of the schematic configuration of the analysis system 10 has been explained. As the analysis system 10, it is preferably an analysis system 10 using the on-line solid-phase extraction method (hereinafter also referred to as the automatic analysis system 10). With the automatic analysis system 10, the measurer does not come into contact with the sample to be measured, there are no individual differences among measurers, and rapid 94 analysis of Nb is possible in case of emergency. Hereinafter, the automatic analysis system 10 will be described.

[0023] FIG. 2 is a diagram for explaining a method of adsorbing 94 Nb contained in the sample solution to the column in an example of an analysis system using the on-line solid-phase extraction method. FIG. 3 is a diagram for explaining a method of eluting 94 Nb adsorbed on the column and introducing it into the inductively coupled plasma mass spectrometer in an example of an analysis system using the on-line solid-phase extraction method. As shown in FIGS. 2 and 3, the automatic analysis system 10 further includes a flow path switching device 5 as a main component. The solution supply device 1 includes two devices, a first solution supply device 1a and a second solution supply device 1b. Note that the solution supply device 1 may be two or more.

[0024] The flow path switching device 5 is provided between the solution supply devices 1a and 1b and the column 3. The flow path switching device 5 switches the flow path so as to introduce a plurality of types of solutions from the solution supply devices 1a and 1b into the column 3 at a predetermined flow rate and in a predetermined order. The flow path switching device 5 may be a commercially available six-way valve or the like. The material of the wetted part of the flow path switching device 5 preferably does not contain metal, and the material is preferably a resin such as polyetheretherketone (PEEK).

[0025] In the example shown in FIG. 2, the sample injection device 2 injects a sample containing Nb, which is an analyte, into a predetermined solution supplied from the first solution supply device 1a to prepare a sample solution. The first solution supply device 1a introduces the sample solution into the column 3 filled with silica gel through the first pipe 9a, the second port 52, and the first port 51 of the flow path switching device 5. The sample solution after passing through the column 3 is discarded into a waste liquid tank 6 or the like through the fourth port 54 and the third port 53 of the flow path switching device 5. Thereby, Nb can be automatically adsorbed on the column 3. 94 94

[0026] After introducing a certain amount of the sample solution into the column 3, it is preferable to move the probe of the automatic injection device 2 to a cleaning position containing a cleaning solution, supply the cleaning solution with the first solution supply device 1a, and clean the inside of the column 3 with the cleaning solution.

[0027] FIG. 3 is a diagram for explaining a method of eluting Nb adsorbed on a column and introducing it into an inductively coupled plasma mass spectrometer 4 in an analysis system using an on-line solid phase extraction method. 94 In the example shown in FIG. 3, the second solution supply device 1b supplies the eluent through the second pipe 9b, the sixth port 56, and the first port 51 of the flow path switching device 5.​​​94 It is supplied to column 3 on which Nb is adsorbed. The 94 Nb adsorbed on column 3 is eluted by the eluent and introduced into mixer 7 through the fourth port 54 and the fifth port 55 of the flow path switching device 5. In addition to the eluent which is the eluate after passing column 3, an internal standard solution is supplied to mixer 7 through the third pipe 9c by the second solution supply device 1b. The eluate and the internal standard solution are mixed by mixer 7, and this mixed solution is introduced into the inductively coupled plasma mass spectrometer 4 through the ultrasonic nebulizer 8 by the solution supply device 1b. Thereby, the 94 Nb adsorbed on column 3 can be eluted and automatically introduced into the inductively coupled plasma mass spectrometer 4. Note that the ultrasonic nebulizer 8 is optionally used as needed from the viewpoint of improving sensitivity.

[0028] Also, when 94 eluting Nb adsorbed on the column and introducing it into the inductively coupled plasma mass spectrometer 4, the flow paths connecting the sixth port 56 and the fifth port 55 of the flow path switching device 5 in FIGS. 2 and 3 are switched, and the supply of the eluent from the second solution supply device 1b is from the fifth port 55, the fourth port 54, 94 through column 3 on which Nb is adsorbed, the first port 51, the sixth port 56, mixer 7, ultrasonic nebulizer 8 to the inductively coupled plasma mass spectrometer 4. In a so-called backflush, the 94 Nb adsorbed on column 3 may be eluted and introduced into the inductively coupled plasma mass spectrometer 4. Also, as shown in FIGS. 2 and 3, the sample injection device 2 may be installed upstream of the solution supply device 1a, or may be installed in the middle of the flow path between the solution supply device 1a and the flow path switching device 5.

[0029] (Analysis method) The analysis method of this embodiment uses the above-described analysis system. FIG. 4 shows an example of a flowchart of the analysis method. The analysis method of this embodiment 94 includes a step of adsorbing Nb (ST01), 94 a step of eluting Nb (ST03), 94It includes the step (ST04) of qualitatively and / or quantitatively analyzing Nb. If necessary, 94 After the step of adsorbing Nb and 94 Before the step of eluting Nb, it further includes the step (ST02) of cleaning the column.

[0030] 94 [The step (ST01) of adsorbing Nb] 94 In the step of adsorbing Nb, a sample solution is introduced into a column filled with silica gel, and the Nb contained in the sample solution is adsorbed by the column (ST01). 94 Nb is adsorbed (ST01). The volume of the sample solution used and the flow rate when passing the solution through the column are not particularly limited and can be appropriately designed.

[0031] <Column> The inner diameter, length, etc. of the column are not particularly limited. For example, it can be appropriately designed according to the filling amount of silica gel, etc. The column includes a solid-phase extraction column used in an on-line solid-phase extraction method, etc. The solid-phase extraction column is a type of column in which a stationary phase is constituted by a carrier or a packing agent. It refers to a column in which a carrier or a packing agent is filled between resin filters or a monolithic carrier is filled in a glass or resin column tube to constitute a stationary phase. Note that the carrier and the packing agent have the same meaning. The column temperature during analysis is not particularly limited and may be at room temperature.

[0032] The column is filled with silica gel. The silica gel is not particularly limited. For example, those commonly used in chromatographic treatment (commercially available products) can be used. Examples of commercially available silica gels include, for example, spherical silica gel Unibeads (GL Sciences Inc.), spherical silica gel Unipak S (GL Sciences Inc.), crushed silica gel InertSep SI (GL Sciences Inc.), etc.

[0033] ​The average particle size of the silica gel is not particularly limited, but is preferably 10 to 500 μm, more preferably 20 to 300 μm, and still more preferably 30 to 200 μm.

[0034] The average pore diameter of the silica gel is not particularly limited, but is preferably 1 nm or more, more preferably 5 nm or more, and still more preferably 10 nm or more. Further, the average pore diameter of the silica gel is preferably 60 nm or less, more preferably 50 nm or less, and still more preferably 40 nm or less. If the average pore diameter is within the above range, 94 the diffusion of Nb becomes easy, and the adsorption by van der Waals force is promoted, and it is estimated that Nb can be adsorbed efficiently. 94 Note that the average pore diameter of the silica gel means the average value of the pore diameters of the silica gel.

[0035] The specific surface area of the silica gel is not particularly limited, but is preferably 50 to 1000 m 2 / g, more preferably 100 to 900 m 2 / g, and still more preferably 200 to 700 m 2 / g.

[0036] The adsorption capacity of the silica gel is not particularly limited, but is preferably 0.5 to 5.0 mg / g, more preferably 0.7 to 4.0 mg / g, and still more preferably 1.0 to 3.0 mg / g.

[0037] The filling amount of the silica gel is not particularly limited, but is preferably 40 to 400 mg / cm as the weight of the silica gel with respect to the column volume 3 , more preferably 40 to 200 mg / cm 3 , and still more preferably 90 to 105 mg / cm 3 . By the filling amount of the silica gel being within the above range, Nb can be separated and purified simply and efficiently. 94

[0038] <Sample solution> The sample solution contains Nb which is the analyte. 94 ​​​The sample solution 94 In addition to Nb, it may contain a plurality of radioisotopes. The radioisotopes that can be contained in the sample solution are not particularly limited. For example, hydrogen-3 ( 3 H), beryllium-7 ( 7 Be), carbon-11 ( 11 C), carbon-14 ( 14 C), nitrogen-13 ( 13 N), fluorine-18 ( 18 F), oxygen-15 ( 15 O), sodium-24 ( 24 Na), magnesium-28 ( 28 Mg), chlorine-38 ( 38 Cl), potassium-38 ( 38 K), chlorine-39 ( 39 Cl), potassium-42 ( 42 K), potassium-43 ( 43 K), scandium-43 ( 43 Sc), scandium-44 ( 44 Sc), scandium-46 ( 46 Sc), scandium-47 ( 47 Sc), titanium-44 ( 44 Ti), vanadium-48 ( 48 V), iron-55 ( 55 Fe), cobalt-56 ( 56 Co), cobalt-57 ( 57 Co), cobalt-58 ( 58 Co), cobalt-60 ( 60 Co), nickel-57 ( 57 Ni), copper-60 ( 60 Cu), copper-61 ( 61 Cu), zinc-62 ( 62 Zn), copper-64 ( 64 Cu), copper-67 ( 67 Cu), germanium-68 ( 68 Ge), gallium-67 ( 67 Ga), gallium-68 ( 68 Ga), arsenic-74 ( 74 As), bromine-76 ( 76 Br), krypton-81 ( 81 Kr), rubidium-81(81 Rb), Rubidium-82( 82 Rb), Rubidium-83( 83 Rb), Rubidium-84( 84 Rb), Rubidium-86( 86 Rb), Yttrium-86( 86 Y), Yttrium-87( 87 Y), Yttrium-90( 90 Y), Strontium-89( 89 Sr), Zirconium-88( 88 Zr), Zirconium-89( 89 Zr), Zirconium-95( 95 Zr), Niobium-90( 90 Nb), Niobium-91( 91 Nb), Niobium-92( 92 Nb), Niobium-95( 95 Nb), Molybdenum-93( 93 Mo), Molybdenum-99( 99 Mo), Technetium-93( 93 Tc), Technetium-94( 94 Tc), Technetium-95( 95 Tc), Technetium-96( 96 Tc), Technetium-99( 99 Tc), Cadmium-107( 107 Cd), Indium-111( 111 In), Antimony-124( 124 Sb), Tellurium-121( 121 Te), Iodine-123( 123 I), Iodine-124( 124 I), Iodine-125( 125 I), Iodine-131( 131 I), Cesium-127( 127 Cs), Cesium-132( 132 Cs), Cesium-136( 136 Cs), Lanthanum-135( 135 La), Barium-140( 140 Ba), Cerium-139( 139 Ce), Neodymium-141( 141 Nd), Promethium-143( 143Promethium-148 (Pm) 148 Terbium-149 (Tb) 149 Terbium-161 (Tb) 161 Europium-145 (Eu) 145 Europium-148 (Eu) 148 Samarium-153 (Sm) 153 Holmium-166 (Ho) 166 Ytterbium-167 (Yb) 167 Ytterbium-169 (Yb) 169 Lutetium-171 (Lu) 171 Lutetium-177 (Lu) 177 Hafnium-171 (Hf) 171 Hafnium-172 (Hf) 172 Hafnium-173 (Hf) 173 Hafnium-175 (Hf) 175 Tantalum-169 (Ta) 169 Tantalum-177 (Ta) 177 Tantalum-178 (Ta) 178 Tantalum-179 (Ta) 179 Tungsten-177 (W) 177 Tungsten-178 (W) 178 Tungsten-179 (W) 179 Tungsten-181 (W) 181 Rhenium-180 (Re) 180 Rhenium-183 (Re) 183 Rhenium-184 (Re) 184 Rhenium-186 (Re) 186 Rhenium-188 (Re) 188 Platinum-188 (Pt) 188 Platinum-191 (Pt) 191 Iridium-192 (Ir) 192 Gold-195 (Au) 195 Gold-196 (Au) 196 Gold-198 (Au) 198 Thallium-201 (Tl) 201 Thallium-202 (Tl) 202 Lead-201 (Pb) 201 Lead-203 (Pb) 203Pb), bismuth-207( 207 Bi), bismuth-212( 212 Bi), bismuth-213( 213 Bi), astatine-207( 207 At), astatine-210( 210 At), francium-213( 213 Fr), actinium-225( 225 Ac), radium-223( 223 Ra), radium-224( 224 Ra), uranium-230( 230 U), uranium-235( 235 U), thorium-226( 226 Th), thorium-227( 227 Th), neptunium-238( 238 Np), mendelevium-255( 255 Md), etc. can be mentioned.

[0039] Also, the sample solution is the analyte 94 Zirconium 94 ([ 94 94 Zr) which is an isobar of Nb, and molybdenum 94 ([ 94 94 Mo), etc. may be included.

[0040] The aqueous solution for preparing the sample solution 94 From the viewpoint of excellent adsorption of Nb to silica gel, it is preferably an acidic aqueous solution containing at least one of hydrochloric acid aqueous solution and nitric acid aqueous solution. Among these, as the aqueous solution for preparing the sample solution, 94 From the viewpoint of separation between Nb and 94 the isobar of Nb, hydrochloric acid aqueous solution is particularly preferred.

[0041] The nitric acid concentration of the nitric acid aqueous solution is preferably 0.5 mol / L or more, more preferably 0.7 mol / L or more, and still more preferably 1.0 mol / L or more. Also, the nitric acid concentration of the nitric acid aqueous solution is preferably 7 mol / L or less, more preferably 6 mol / L or less, and still more preferably 5 mol / L or less. If the nitric acid concentration of the nitric acid aqueous solution is within the above range, the 94 adsorption rate of Nb to silica gel tends to be excellent.

[0042] The hydrochloric acid concentration of the hydrochloric acid aqueous solution is preferably 0.5 mol / L or more, more preferably 0.7 mol / L or more, and still more preferably 1.0 mol / L or more. Also, the hydrochloric acid concentration of the hydrochloric acid aqueous solution is preferably 7 mol / L or less, more preferably 6 mol / L or less, and still more preferably 5 mol / L or less. If the hydrochloric acid concentration of the hydrochloric acid aqueous solution is within the above range, the 94 adsorption rate of Nb to silica gel tends to be excellent.

[0043] The aqueous solution for preparing the sample solution may contain sulfates such as sodium sulfate, potassium sulfate, and ammonium sulfate, if necessary. When the sample solution contains a sulfate, the 94 adsorption rate of Nb to silica gel tends to improve.

[0044] [Step of washing the column (ST02)] 94 After the step of adsorbing Nb (ST01), a step of washing the column is performed as necessary. The step of washing the column is 94 washing the column on which Nb is adsorbed with a washing solution (ST02).

[0045] The amount of the solution of the washing solution used and the flow rate when passing through the column are not particularly limited and can be appropriately designed. As the washing solution, the same aqueous solution as the aqueous solution for preparing the above-described sample solution can be used.

[0046] 94 [Step of eluting Nb (ST03)] 94 After the step of adsorbing Nb (ST01) or after the step of washing the column (ST02), 94 a step of eluting Nb is performed.

[0047] 94 The step of eluting Nb is to separate Nb with a column using an eluent and 94 elute Nb from the column (ST03). 94 ​​The amount of the eluent solution used and the flow rate when passing the solution through the column are not particularly limited and can be appropriately designed.

[0048] <Eluent> The eluent is from the column 94 From the viewpoint of excellent elution of Nb, an oxalic acid aqueous solution is preferred. The oxalic acid concentration of the oxalic acid aqueous solution is preferably 0.0075 mol / L or more, more preferably 0.01 mol / L or more. If the oxalic acid concentration of the oxalic acid aqueous solution is at or above the above lower limit value, 94 It is excellent in the elution rate of Nb from silica gel and tends to be analyzable with high sensitivity in an inductively coupled plasma mass spectrometer. The upper limit value of the oxalic acid concentration of the oxalic acid aqueous solution is not particularly limited, but is usually 0.1 mol / L or less.

[0049] 94 [Step (ST04) of Qualitatively and / or Quantitatively Analyzing Nb] 94 After the step (ST03) of eluting Nb, 94 A step of qualitatively and / or quantitatively analyzing Nb is performed. 94 In the step of qualitatively and / or quantitatively analyzing Nb, the eluate from the column is measured by an inductively coupled plasma mass spectrometer, 94 To qualitatively and / or quantitatively analyze Nb (ST04).

[0050] 94 In the quantitative analysis of Nb, it is performed by creating a calibration curve (a graph plotting the relationship between the peak intensity and the known concentration). Specifically, by measuring a plurality of Nb standard solutions with known concentrations to obtain chromatograms at a plurality of concentrations, 94 A calibration curve of Nb is created. By correlating the peak intensity of Nb in a sample with an unknown concentration to this calibration curve, 94 The concentration of Nb can be quantified. Since the linearity of the graph of the calibration curve of the analysis method of this embodiment is very good, the Nb concentration in the sample can be measured with excellent accuracy. 94 94 Nb concentration can be measured. 94

[0051] ​​​As described above, the analysis method and analysis system of the present embodiment combine a column filled with silica gel and an inductively coupled plasma mass spectrometer, 94 so that the elements of the isomers of Nb can be significantly separated and removed from the sample solution by a column filled with silica gel, and then the unwanted elements can be further removed and detected by an inductively coupled plasma mass spectrometer. Furthermore, by introducing ammonia gas into the collision / reaction cell of the inductively coupled plasma mass spectrometer, 94 the isomers of Nb can be more reliably removed. In addition, the analysis method and analysis system of the present embodiment enable automatic analysis using the on-line solid phase extraction method, and can analyze Nb simply and with high precision. 94

[0052] As described above, the present invention has been described by showing preferred embodiments for ease of understanding. Hereinafter, the present invention will be described based on examples. However, the above description and the following examples are provided for illustrative purposes only and not for the purpose of limiting the present invention. In the following examples, for the solution supply device 1, the sample injection device 2, the column tube for manufacturing the column 3, the flow path switching device 5, and the piping between them, commercially available liquid feed pumps, autosamplers, column tubes, six-way valves, and piping were used, and the material of the liquid contact part was a resin such as polyether ether ketone (PEEK).

Example

[0053] (Example 1: Examination of the aqueous solution for preparing the sample solution) 94 In the mass spectrometry of Nb, 94 Zr, 94 Mo interfere. Furthermore, 54 Cr 40 Ar, 56 Fe 38 Ar, 59 Co 35 Cl, 58 Ni 36 Ar, etc. also interfere. Therefore, 94 in the aqueous solution for preparing the sample solution that is passed through the column filled with silica gel together with Nb,​94 Nb is adsorbed, 94 For the aqueous solution for preparing the sample solution, the above elements that interfere with Nb are hardly adsorbed. Since radioisotopes have the same chemical properties as stable isotopes, various studies were first carried out using stable isotopes.

[0054] Approximately 0.25 g of silica gel (spherical silica gel, average particle size: 150 μm, average pore size: 12 nm, manufactured by GL Sciences Inc.) was filled into a PEEK column tube (inner diameter 4 mm × length 50 mm) to prepare a column. To this column, a 68-element mixed standard solution containing Nb (each element concentration: 100 ppb, manufactured by PerkinElmer) was adsorbed at a flow rate of 1 mL / min using 30 mL each of a 1 mol / L nitric acid aqueous solution (HNO 3 aqueous solution) or a hydrochloric acid aqueous solution with a hydrochloric acid concentration of 1 mol / L (HCl aqueous solution) as the aqueous solution for preparing the sample solution. After collecting the column eluate, it was measured by an inductively coupled plasma mass spectrometer (ICP-MS / MS NexION, manufactured by PerkinElmer), and the adsorption rate (%) was calculated from the concentration after passing the original solution (column eluate) and the concentration of the original solution (sample solution) using the following formula. The results are shown in Figure 5.

[0055] Adsorption rate (%) = (1 - (concentration after passing the original solution (ppb)) / (concentration of the original solution (ppb))) × 100

[0056] 94 The adsorption rate (%) of Nb is preferably 70% or more, more preferably 80% or more, and still more preferably 90% or more. Also, 94 The adsorption rate (%) of the Nb isotope is preferably 15% or less, more preferably 10% or less, and still more preferably 5% or less. When nitric acid aqueous solution or hydrochloric acid aqueous solution was used as the aqueous solution for preparing the sample solution, the adsorption rate of Nb was high and good. On the other hand, the adsorption rates of elements such as Cr that interfere with Nb, and the isobars Zr and Mo were low and good. Although tantalum (Ta) was adsorbed by 95% or more, Ta has a different mass number from Nb. Therefore, it can be removed by the quadrupole mass filter of the inductively coupled plasma mass spectrometer, and Ta may be adsorbed on the silica gel.

[0057] Also, when comparing the nitric acid aqueous solution and the hydrochloric acid aqueous solution, the adsorption rates of Fe, Co, and Ni were lower when the hydrochloric acid aqueous solution was used. Therefore, it was found that the hydrochloric acid aqueous solution is more preferable as the aqueous solution for preparing the sample solution.

[0058] Since it was found that the hydrochloric acid aqueous solution is excellent as the aqueous solution for preparing the sample solution, subsequently, the hydrochloric acid concentration of the hydrochloric acid aqueous solution as the aqueous solution for preparing the sample solution was examined. Instead of the 68 - element mixed standard solution, an Nb, Zr, and Mo mixed standard solution (each element concentration: 100 ppb, FUJIFILM Wako Pure Chemical Corporation) was used, and the adsorption rate (%) was calculated by performing the same operations as the above - described method except that hydrochloric acid aqueous solutions with five kinds of hydrochloric acid concentrations of 1, 3, 5, 8, and 10 mol / L were used as the aqueous solution for preparing the sample solution. The results are shown in Fig. 6.

[0059] Fig. 6 is a diagram showing the change in the adsorption rate of Nb when the hydrochloric acid concentration of the hydrochloric acid aqueous solution is changed. The horizontal axis in Fig. 6 is the hydrochloric acid concentration of the hydrochloric acid aqueous solution, and the vertical axis is the adsorption rate (%). In the case of hydrochloric acid aqueous solutions with hydrochloric acid concentrations of 1 mol / L to 5 mol / L, the adsorption rate of Nb was 93% or more. On the other hand, the adsorption rates of Zr and Mo were 7.1% or less. Therefore, it was found that it is particularly preferable to use a hydrochloric acid aqueous solution with a hydrochloric acid concentration of 1 mol / L to 5 mol / L as the aqueous solution for preparing the sample solution.

[0060] (Example 2: Examination of the cleaning solution) Since it was found that it is particularly preferable to use an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 1 mol / L to 5 mol / L as the aqueous solution for preparing the sample solution in Example 1, the cleaning solution was subsequently examined. Example 2 was carried out in the same manner as Example 1, except that a step of washing the column on which Nb was adsorbed with a cleaning solution was added. The aqueous solution for preparing the sample solution was an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 1 mol / L. As the cleaning solution, 5 mL each of ultrapure water, an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 1 mol / L, or an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 5 mol / L was used. The column washing was performed at a flow rate of 1 mL / min.

[0061] First, using a mixed standard solution of Nb, Zr, and Mo (each element concentration: 100 ppb, manufactured by PerkinElmer) as a sample, in a sample solution prepared using 30 mL of an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 1 mol / L as the aqueous solution for preparing the sample solution, the adsorption rates (%) of Nb, Zr, and Mo were calculated by the formula shown in Example 1 from the concentration of the eluate after passing the original solution (eluate) and the concentration of the original solution (sample solution) at a flow rate of 1 mL / min.

[0062] Next, the cleaning solution after washing the column on which Nb, Zr, and Mo were adsorbed was collected and measured by an inductively coupled plasma mass spectrometer. The residual rate (%) of the ions (metal ions) of each element after washing on the column was calculated as the residual rate after washing by the following formula. The results are shown in Table 1.

[0063] Residual rate after washing (%) = (adsorption amount of metal ions on the column (μg) - elution amount of metal ions contained in the cleaning solution after column washing (μg)) / concentration of the original solution (ppb) × volume of the original solution passed (L) × 100

[0064]

Table 1

[0065] After washing 94 The residual rate (%) of Nb is preferably 70% or more, more preferably 80% or more, and still more preferably 85% or more. Also, 94The residual ratio (%) of the Nb isomers after washing is preferably 10% or less, more preferably 5% or less, and still more preferably 3% or less. As shown in Table 1, when the cleaning solution is an aqueous hydrochloric acid solution with a hydrochloric acid concentration of 1 mol / L to 5 mol / L, it was found that Zr and Mo can be almost completely removed while suppressing the desorption of Nb.

[0066] (Example 3: Examination of the eluent) Subsequently, the eluent was examined. Example 3 was carried out in the same manner as Example 2, except that a step of passing the eluent through the column after washing was added. The cleaning solution was an aqueous hydrochloric acid solution with a hydrochloric acid concentration of 5 mol / L. As the eluent, 5 mL each of an aqueous oxalic acid solution with an oxalic acid concentration of 0.001 mol / L or an aqueous oxalic acid solution with an oxalic acid concentration of 0.01 mol / L was used. The flow rate of the eluent was 1 mL / min. After adsorbing Nb, Zr, and Mo, and collecting the eluent (eluate) after passing it through the column after washing, it was measured by an inductively coupled plasma mass spectrometer, and the elution rate (%) was calculated by the following formula. The results are shown in Table 2.

[0067] Elution rate (%) = (concentration of eluate (ppb) × flow rate of eluate (mL)) / (concentration of original solution (ppb) × flow rate of original solution (mL) × adsorption rate) × 100

[0068]

Table 2

[0069] 94 The elution rate (%) of Nb is preferably 70% or more, more preferably 80% or more, and still more preferably 90% or more. As shown in Table 2, it was found that an aqueous oxalic acid solution having an oxalic acid concentration of 0.01 mol / L or more is suitable as the eluent.

[0070] (Example 4: Examination of the filler) Subsequently, fillers were examined. Approximately 0.25 g of three types of silica gels (spherical silica gels, manufactured by GL Sciences Inc.) with different physical properties shown in Table 3 were filled into a PEEK column tube (inner diameter 4 mm × length 50 mm) to fabricate a column. A mixed standard solution of Nb, Zr, and Mo (concentration of each element: 100 ppb, manufactured by FUJIFILM Wako Pure Chemical Corporation) and 30 mL of an aqueous hydrochloric acid solution with a hydrochloric acid concentration of 1 mol / L were used as an aqueous solution for preparing a sample solution, and were adsorbed onto the column at a flow rate of 1 mL / min. After collecting the column eluate, it was measured using an inductively coupled plasma mass spectrometer (ICP-MS / MS NexION, manufactured by PerkinElmer Inc.), and the adsorption rate (%) was calculated using the formula shown in Example 1. The results are shown in Table 3.

[0071]

Table 3

[0072] For Silica gels 1 to 3, the adsorption rate of Nb was 93% or more, which was good. Among these, Silica gel 1 had a lower adsorption rate of Zr and Mo compared to Silica gels 2 and 3, and was excellent as a filler.

[0073] (Example 5: Examination Using Radioisotopes) In Example 5, the analysis methods of Examples 1 to 4 optimized with stable isotopes were examined using radioisotopes. An environmental water sample of river water, well water, or seawater was mixed with Nb having a radioactivity concentration of 241 Bq / L (3 ppb). 94 Silica gel 1 of Example 4 (spherical silica gel, average particle diameter: 150 μm, average pore diameter: 12 nm, manufactured by GL Sciences Inc.) was used as a filler for the column, an aqueous hydrochloric acid solution with a hydrochloric acid concentration of 1 mol / L was used as an aqueous solution for preparing a sample solution, an aqueous hydrochloric acid solution with a hydrochloric acid concentration of 5 mol / L was used as a washing solution, and an aqueous oxalic acid solution with an oxalic acid concentration of 0.01 mol / L was used as an eluent, and the same operations as in Example 3 were performed. After collecting the eluate (elution solution) after passing the solution through the column, it was measured using a germanium semiconductor detector, and the recovery rate (%) of Nb in each environmental water sample was calculated using the following formula. 94 The recovery rate (%) of Nb in each environmental water sample was calculated using the following formula.

[0074] Recovery rate (%) = Radioactivity of eluate (Bq) / Radioactivity of original solution (Bq) × 100

[0075]

Table 4

[0076] 94 The recovery rate of Nb (%) is preferably 70% or more, more preferably 80% or more, and still more preferably 90% or more. As shown in Table 4, it was demonstrated that a high recovery rate can be obtained even for the radioisotope contained in the actual sample by the analysis method of the present embodiment 94 for Nb.

[0077] (Example 6: Interference removal of isobars by collision reaction cell) By the above method using a column filled with silica gel 94 Nb and 94 Although the separation between Nb and its isobar has been achieved, it is preferable to further remove the interference of the isobar by an inductively coupled plasma mass spectrometer. Therefore, by supplying a reaction gas into the collision reaction cell, due to the difference in reactivity between these gases and each radioisotope, 94 Nb and 94 An experiment was conducted using a sample containing a stable isotope of Nb and an isobar of Nb to examine whether removal by separation between Nb and its isobar is possible.

[0078] Ammonia gas was introduced into the collision reaction cell of the inductively coupled plasma mass spectrometer in a flow rate range of 0 to 3 mL / min, and a mixed standard solution of Nb, Zr, and Mo (concentration of each element: 100 ppt, PerkinElmer) was measured by an inductively coupled plasma mass spectrometer (ICP-MS / MS NexION, PerkinElmer). The results are shown in FIGS. 7A to 7C.

[0079] Figures 7A to 7C show the difference in the flow rate of ammonia gas and the products resulting from the reaction of ammonia gas with Nb, Zr, and Mo in a collision reaction cell. The horizontal axis represents the introduction flow rate of ammonia gas into the collision reaction cell, and the vertical axis represents the peak intensity obtained by an inductively coupled plasma mass spectrometer.

[0080] As shown in FIGS. 7B and 7C, for Zr and Mo, no ammonia adduct with a mass number increased by 81 was formed at any flow rate of ammonia gas. On the other hand, as shown in FIG. 7A, an ammonia adduct was formed only for Nb at an ammonia gas flow rate of 0.3 to 2.4 mL / min. Therefore, it was found that by introducing ammonia gas into the collision reaction cell in mass spectrometry and setting the flow rate of ammonia gas to 0.3 to 2.4 mL / min, interference by the isomers of Nb can be removed. Note that from the viewpoint of detection intensity, the flow rate of the introduced ammonia gas is preferably 0.5 to 1.5 mL / min, and particularly preferably 0.7 mL / min.

[0081] (Example 7: Implementation of an Automatic Analysis System) A flow injection (FI) system was constructed by combining an autosampler as a sample injection device, a six-way valve as a flow path switching device, and a peristaltic pump as a solution supply device, and an automatic analysis system using an on-line solid phase extraction method was constructed. The column and the inductively coupled plasma mass spectrometer were connected as shown in FIG. 2 or FIG. 3 using a six-way valve, and the switching of the six-way valve as the flow path switching device was performed according to the program shown in Table 5. In Table 5, “A” in the valve position item is the position of the six-way valve in FIG. 2 (hereinafter also referred to as the sample loading position), and “B” is the position of the six-way valve in FIG. 3 (hereinafter also referred to as the sample elution position). Also, the liquid delivery pump P1 shown in Table 5 supplied the column conditioning solution, the sample solution, and the cleaning solution, and the liquid delivery pump P2 supplied the eluent and the internal standard solution. As the internal standard solution, an indium standard solution (concentration: 100 ppt) was used. In Table 5, “s” means “second”.

[0082]

Table 5

[0083] First, at the sample loading position, approximately 0.25 g of silica gel 1 of Example 4 (spherical silica gel, average particle size 150 μm, average pore size 12 nm, manufactured by GL Sciences Inc.) was filled into a PEEK column tube (inner diameter 4 mm × length 50 mm) to prepare a column. A conditioning solution (hydrochloric acid aqueous solution with a hydrochloric acid concentration of 1.0 mol / L) was passed through the column at a flow rate of 2 mL / min for 300 s to condition the column. Next, a sample solution containing Nb (prepared with a hydrochloric acid aqueous solution with a hydrochloric acid concentration of 1.0 mol / L) was passed through the column at a flow rate of 2 mL / min for 350 s to adsorb Nb onto the column. Then, a cleaning solution (hydrochloric acid aqueous solution with a hydrochloric acid concentration of 5.0 mol / L) was passed through the column at a flow rate of 2 mL / min for 300 s to clean the column. Next, the column was switched to the sample elution position, and an eluent (oxalic acid aqueous solution with an oxalic acid concentration of 0.01 mol / L) was passed through the column at a flow rate of 2 mL / min for 300 s to elute Nb from the column. The eluate was introduced into a mixer, and after mixing the eluate and the internal standard solution with the mixer, it was introduced into an inductively coupled plasma mass spectrometer (ICP-MS / MS NexION, manufactured by PerkinElmer Inc.) equipped with an ultrasonic nebulizer. Ammonia gas was introduced into the collision / reaction cell of the ICP-MS / MS at 0.7 ml / min from the start of detection to the end of detection. The monitor ions of the ICP-MS / MS were set as Q1: m / z94 and Q2: m / z175. The obtained chromatogram is shown in Fig. 8, and the calibration curve is shown in Fig. 9.

[0084] Fig. 8 is a diagram showing the chromatograms of Nb at 50, 100, and 200 ppb. The horizontal axis represents time (s (seconds)), and the vertical axis represents the Nb intensity (10 9 cps). Fig. 9 is a diagram showing the calibration curve of Nb. The horizontal axis represents the Nb concentration (ppb), and the vertical axis represents the Nb integrated intensity (10 10 cps).

[0085] As shown in Fig. 8, the peak shape of Nb was good, and the peak area increased depending on the concentration of Nb. Also, as shown in Fig. 9, the correlation coefficient of the calibration curve was 0.9986, indicating excellent linearity.

[0086] Therefore, it was demonstrated that by the analysis method and analysis system of the present embodiment, Nb can be accurately quantified by automatic analysis even at a low concentration of 50 ppb without complicated pretreatment.

[0087] (Example 8: Measurement using actual samples) Using cement as an actual sample, measurement was performed by an automatic analysis system using the on-line solid phase extraction method described in Example 7 (automatic analysis system measurement). 94 It was confirmed that Nb could be accurately quantified. Therefore, the analysis method and analysis system of the present embodiment are 94 also confirmed to be applicable to the analysis of Nb contained in actual wastes such as cement.

Industrial applicability

[0088] According to the present invention, Nb can be automatically analyzed simply and with high accuracy without requiring complicated processes, 94 so it can be applied to various environmental analysis institutions and workplaces.

Explanation of symbols

[0089] 1 ··· Solution supply device, 1a ··· First solution supply device, 1b ··· Second solution supply device, 2 ··· Sample injection device, 3 ··· Column, 4 ··· Inductively coupled plasma mass spectrometer, 5 ··· Flow path switching device, 6 ··· Waste liquid tank, 7 ··· Mixer, 8 ··· Ultrasonic nebulizer, 9a ··· First pipe, 9b ··· Second pipe, 9c ··· Third pipe, 10 ··· Analysis system, 41 ··· Front-stage quadrupole (Q1), 42 ··· Collision / reaction cell, 43 ··· Rear-stage quadrupole (Q2), 44 ··· Detector, 51 ··· First port, 52 ··· Second port, 53 ··· Third port, 54 ··· Fourth port, 55 ··· Fifth port, 56 ··· Sixth port

Claims

1. A step of introducing a sample solution into a column filled with silica gel and adsorbing niobium 94 ( ９４ Nb) contained in the sample solution onto the column; A step of separating niobium 94 with the column using an eluent and eluting niobium 94 from the column; A step of measuring the eluate from the column with an inductively coupled plasma mass spectrometer to qualitatively and / or quantitatively analyze niobium 94, A method for analyzing niobium 94.

2. The method for analyzing niobium 94 according to Claim 1, wherein the aqueous solution for preparing the sample solution is an acidic aqueous solution containing at least one of an aqueous hydrochloric acid solution and an aqueous nitric acid solution.

3. The method for analyzing niobium 94 according to Claim 1, wherein the aqueous solution for preparing the sample solution is an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 0.5 mol / L to 7 mol / L.

4. The sample solution contains niobium 94, zirconium 94 ( ９４ Zr), and molybdenum 94 ( ９４ Mo), and is the method for analyzing niobium 94 according to claim 1.

5. The method for analyzing niobium 94 according to Claim 1, wherein the eluent is an aqueous oxalic acid solution having an oxalic acid concentration of 0.01 mol / L or more.

6. After the step of adsorbing and before the step of eluting, the method further includes a step of washing the column on which niobium 94 is adsorbed with a washing solution, The method for analyzing niobium 94 according to Claim 1, wherein the washing solution is an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 0.5 mol / L to 7 mol / L.

7. The method for analyzing niobium 94 according to Claim 1, wherein the average pore diameter of the silica gel is 10 nm to 50 nm.

8. The step of qualitatively and / or quantitatively analyzing is to introduce a reaction gas containing ammonia together with the eluate from the column into the inductively coupled plasma mass spectrometer to detect an ammonia adduct of niobium 94, and the method for analyzing niobium 94 according to any one of Claims 1 to 7.

9. Analysis system for niobium 94 ( ９４ Nb) used in the analysis method of niobium 94, A column filled with silica gel; A solution supply device for supplying a plurality of types of solutions; A sample injection device for preparing a sample solution by injecting a sample containing niobium 94 into an aqueous solution for preparing the sample solution supplied from the solution supply device; A flow path switching device for switching the flow path so as to introduce a plurality of types of solutions supplied from the solution supply device into the column in a predetermined flow rate and order; An inductively coupled plasma mass spectrometer for analyzing niobium 94, Introducing a sample solution into a column filled with silica gel and adsorbing niobium 94 contained in the sample solution to the column; Supplying a washing solution to the column on which niobium 94 is adsorbed to wash the column; Supplying an eluent to the washed column to separate niobium 94 and elute niobium 94 from the column; The eluate from the column is measured by an inductively coupled plasma mass spectrometer to qualitatively and / or quantitatively analyze niobium 94. An analytical system for niobium 94. **Claim 10** The aqueous solution for preparing the sample solution is an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 0.5 mol / L to 7 mol / L. The cleaning solution is an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 0.5 mol / L to 7 mol / L. The eluent is an aqueous oxalic acid solution having an oxalic acid concentration of 0.01 mol / L or more. The average pore diameter of the silica gel is 10 nm to 50 nm. The analytical system for niobium 94 according to claim 9. **Claim 11** The inductively coupled plasma mass spectrometer has a front quadrupole set to a mass-to-charge ratio (m / z) of 94, which is the mass number of niobium 94, a rear quadrupole set to a mass-to-charge ratio (m / z) of 175, which is the mass number of the ammonia adduct of niobium 94, and a collision / reaction cell disposed between the front quadrupole and the rear quadrupole. The analytical system for niobium 94 according to claim 9 or 10.

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