WO2019163394A1

WO2019163394A1 - Method for preparing sample for analysis

Info

Publication number: WO2019163394A1
Application number: PCT/JP2019/002368
Authority: WO
Inventors: 高史末包; 裕志土屋; 奈央金子
Original assignee: 株式会社住化分析センター
Priority date: 2018-02-21
Filing date: 2019-01-24
Publication date: 2019-08-29
Also published as: TW201937148A; TWI794403B; JP7252936B2; JPWO2019163394A1

Abstract

Provided is a novel method for preparing a sample for analysis which enables convenient analysis without limiting the element contained in the sample to boron and/or phosphorus. This method for preparing a sample for analysis is for analyzing an element contained in the sample, and includes a specific incineration step, a specific acid dissolving step, and a specific cation exchange resin contacting step.

Description

Analytical sample preparation method

The present invention relates to a method for preparing a sample for analysis.

In various fields such as semiconductor-related fields, medical device manufacturing fields, food component analysis fields, etc., it may be necessary to analyze and quantify elements contained in samples (raw materials, foods, etc.). Therefore, it is necessary to prepare an analytical sample appropriately for each of these analysis and quantification methods.

When quantifying trace inorganic impurity elements, particularly boron and phosphorus, in a sample, a microwave decomposition method, an ashing method, or the like is generally used as a method for preparing an analysis sample.

In the microwave decomposition method, a sample is heated and dissolved in a closed system with microwaves. Therefore, boron and phosphorus that are easily volatilized at a high temperature can be recovered without loss and subjected to analysis and quantification.

In the ashing method, the amount of sample is not so limited (1 g or more can be processed), and most organic samples can be decomposed.

As a method for quantifying boron, including a method obtained by further improving the ashing method, a quantification method including the following steps (first step) to (fifth step) has been conventionally provided (Patent Document 1): (First step) A step of ashing graphite in the presence of a calcium compound and capturing boron in the graphite in an ash; (Second step) dissolving an ash obtained in the first step with an acid Step of obtaining an ash product aqueous solution; (Third step) Step of capturing boron contained in the ash product aqueous solution obtained in the second step in an anion exchange resin; (Fourth step) Anion exchange resin in the third step A step of eluting boron trapped in the aqueous acid solution to obtain an eluent; (fifth step) a step of quantifying boron in the eluent obtained in the fourth step by inductively coupled plasma-mass spectrometry.

JP 2008-203122 A (published on September 4, 2008)

However, conventional techniques such as a general microwave decomposition method and an ashing method have the following problems.

The microwave decomposition method has a problem that the amount of sample that can be processed is limited (about 0.1 g) and a problem that decomposition is difficult depending on sample properties.

Also, the conventional ashing method has an issue that it is an open system and is processed at a high temperature, so that some elements (particularly boron and phosphorus) may be volatilized during ashing.

In order to solve these technical problems, a method for quantifying boron in graphite has been developed, including a method for preparing an analytical sample based on an ashing method as described above (Patent Document 1). . The technique described in Patent Document 1 has been quite useful in solving the problem of the amount of sample that can be processed or the problem of element volatilization. However, in order to obtain an analytical sample for analyzing an element contained in the sample, development of a more useful analytical sample preparation method has been desired.

For example, in Patent Document 1, the quantifiable element in graphite is boron, and the technique of Patent Document 1 is not a technique for use in quantification other than boron.

One embodiment of the present invention has been made in view of the above-mentioned problems, and its purpose is to simply analyze an element contained in a sample without limiting it to boron and / or phosphorus. It is to provide a novel method for preparing a sample for analysis.

That is, the method for preparing an analytical sample according to an embodiment of the present invention is a method for preparing an analytical sample for analyzing elements contained in the sample, and the sample is ashed in the presence of a capture agent. An ashing step in which the elements in the sample are captured, an ashing step, and an acid lysis step in which an ashed product aqueous solution is obtained by dissolving the ashed product obtained in the ashing step in an acid. And the ash exchange solution obtained in the acid dissolution step and a cation exchange resin to capture the cation of the element derived from the scavenger in the cation exchange resin, and the cation element And a cation exchange resin contact step for obtaining an analysis solution containing an element other than the above.

According to one embodiment of the present invention, an element that is included in a sample is not limited to boron and / or phosphorus, and an analysis sample that can be easily analyzed can be provided. Play.

One embodiment of the present invention will be described below, but the present invention is not limited to this. The present invention is not limited to each configuration described below, and various modifications can be made within the scope shown in the claims. The present invention also includes embodiments and examples obtained by appropriately combining technical means disclosed in different embodiments and examples, and is also included in the technical scope of the present invention. In addition, all the patent documents described in this specification are used as a reference in this specification. Unless otherwise specified in this specification, “A to B” representing a numerical range is intended to be “A or more (including A and greater than A) and B or less (including B and less than B)”.

An analytical sample preparation method according to an embodiment of the present invention is an analytical sample preparation method for analyzing an element contained in a sample, and the sample is ashed in the presence of a capture agent. An ashing step for obtaining an ashed product in which the elements in the sample are captured, and an acid dissolving step for obtaining an ashed product aqueous solution by dissolving the ashed product obtained in the ashing step in an acid, In addition, by contacting the ash product aqueous solution obtained in the acid dissolution step with a cation exchange resin, the cation of the element derived from the scavenger is captured by the cation exchange resin, and other than the cation element And a cation exchange resin contact step for obtaining an analysis solution containing the above elements.

In the present specification, the “method for preparing an analytical sample according to an embodiment of the present invention” is also simply referred to as “the present preparation method”. The term “present preparation method” does not limit the preparation method of the analytical sample at all, and merely indicates one embodiment of the preparation method of the analytical sample.

〔sample〕
The sample that is the object of this preparation method is not particularly limited as long as it can be ashed, and may be a carbon-free sample, a carbon-containing sample, or a combination thereof.

A carbon-free sample is a sample containing only a substance not containing carbon. Examples of the carbon-free sample include metals, ceramics, and aqueous solutions, but are not limited to these as long as they do not contain carbon.

Carbon sample is a sample containing a substance containing carbon. Examples of the “carbon-containing substance” include (1) a substance made of carbon such as graphite, graphene, carbon nanotube, glassy carbon, carbon fiber, carbon black, activated carbon, and (2) a biological sample. Examples include substances containing carbon, and (3) substances containing carbon such as resins, organic compounds, and fluororesins.

The carbon-containing sample only needs to contain a substance containing carbon, and may be a composite of a substance containing carbon and another substance (for example, a graphite composite material). Moreover, the carbon-containing sample may contain only one type of substance containing carbon, or may contain two or more types. The carbon-containing sample may be derived from a natural product or an artificial product. Examples of carbon-containing samples derived from natural products include biological samples; grains such as rice. Moreover, resin etc. are contained in the carbon containing sample derived from an artifact.

As will be described later in detail, the present preparation method includes an ashing step of ashing the sample in the presence of a scavenger to obtain an ash product in which the elements in the sample are captured. From the viewpoint of efficient and complete ashing of the sample, the sample is preferably a carbon-containing sample.

In this preparation method, the sample is usually used in the ashing step of the preparation method in a powder state. When the sample is a lump or a molded object, the sample can be cut or pulverized to form a powder, which can be used in the ashing step of the preparation method. Therefore, in this preparation method, the form and size of the sample are not particularly limited.

The amount of the sample used per time in this preparation method is usually 0.001 g to 100 g, preferably 0.005 g to 50 g, more preferably 0.01 g to 10 g.

[Ashing process]
The ashing step is a step of obtaining an ash in which the elements in the sample are captured by ashing the sample in the presence of the capturing agent.

The scavenger is not particularly limited as long as it is a compound that can capture the measurement target element contained in the sample in the ash during the ashing step. The scavenger may not capture all of the elements contained in the sample in the ash during the ashing step. That is, the capture agent is a compound that can capture boron and phosphorus that can be contained in a sample, and at least one element other than boron and phosphorus, in the ash. As the scavenger, only one of the above compounds can be used alone, or two or more of the above compounds can be used in combination.

The scavenger is a scavenger that can capture the cation of the element derived from the scavenger in the cation exchange resin contact step described later. Thereby, the analysis solution containing elements other than the element of the said cation can be obtained.

Therefore, it is preferable to use a capture agent that does not contain the element to be measured as the capture agent. More preferably, the scavenger does not contain boron and phosphorus that can be contained in the sample, and at least one element other than boron and phosphorus.

Specific examples of the scavenger include compounds containing an alkali metal element, an alkaline earth metal element (for example, calcium), a lanthanoid series element (for example, lanthanum), and the like. These compounds can be used alone or in combination of two or more of the above compounds.

Further, the compound may be an oxide, and for example, calcium oxide, lanthanum oxide and the like can be suitably used. The above compound is usually oxidized in the ashing step to become an oxide, and the element in the sample is considered to be trapped in the ash by combining with this oxide. Therefore, the compound may be an oxide precursor that can be oxidized to an oxide by heating in an atmosphere containing oxygen. Examples of the oxide precursor include carbonates, fluorides, chlorides, nitrates, sulfates, and hydroxides.

As the scavenger, a calcium compound can be suitably used because it is excellent in ability to capture boron and phosphorus that can be contained in the sample, and at least one element other than boron and phosphorus, and is easily available.

Usually, calcium oxide or a precursor thereof is used as the calcium compound. The precursor of calcium oxide can be oxidized to calcium oxide by heating in an atmosphere containing oxygen. Specific examples of the precursor of calcium oxide include calcium carbonate, calcium fluoride, calcium chloride, calcium nitrate, calcium sulfate, and calcium hydroxide. These compounds may be used alone or in combination of two or more. As the calcium compound, a powdery grade is usually used with a grade higher than reagent special grade.

In this preparation method, when a calcium compound is included as a scavenger, the ashing step may have the following configuration. That is, in the ashing step, the sample is ashed in the presence of the calcium compound, and the element in the sample is combined with calcium oxide (CaO) to obtain the ashed product in which the element in the sample is captured. It is.

The amount of the scavenger used is not particularly limited as long as the total amount of the scavenger can be dissolved in the acid dissolution step, but is usually 0.01 mass times to 10 mass times with respect to the sample. is there.

In order to incinerate the sample in the presence of the capture agent, for example, the sample may be mixed with the capture agent and the resulting mixture may be heated. In the ashing step, the sample and the capture agent are preferably heated in a container such as a platinum dish or a platinum crucible. Containers such as platinum dishes, platinum crucibles and the like are inert to (a) the sample, the elements in the sample, and the scavenger, and (b) are heat resistant.

Also, as a container used in the ashing process, an inorganic glass container such as quartz glass, soda lime glass, borosilicate glass, or the like may be used. Among the inorganic glass containers, quartz glass is preferably used in that a high-purity one with particularly few metal impurities can be obtained.

Ashing is performed in an oxygen-containing atmosphere, specifically in an oxygen gas circulation atmosphere, a still air atmosphere, or an air circulation atmosphere, and preferably in an oxygen gas circulation atmosphere. When the ashing step is performed in an oxygen gas flow atmosphere, the flow rate of oxygen gas is preferably 0.5 L / min to 3 L / min in order to efficiently ash the sample.

Heating for ashing may be performed in an electric furnace (electric muffle furnace) equipped with a thermocouple thermometer capable of performing temperature control, or may be performed simply by a burner.

Ashing temperature is usually 500 ° C to 1000 ° C. The ashing time varies depending on the amount of the sample and the capturing agent used, the oxygen concentration in the atmosphere in which the ashing process is performed, and the heating temperature, and can be set as appropriate. By ashing the sample in the presence of the capture agent, an ash product in which the elements in the sample are captured by the capture agent can be obtained.

In the ashing step in this preparation method, the sample is ashed in the presence of the scavenger, so even if the sample contains highly volatile elements (such as boron and phosphorus), the element is contained in the ash. Can be captured.

In the ashing step in the present preparation method, at least one element other than boron and phosphorus can be captured in the ash without volatilizing boron and phosphorus at the same time.

[Acid dissolution step]
The acid dissolution step is a step of obtaining an ash solution by dissolving the ash obtained in the ash step in an acid.

In order to dissolve the ash in acid, for example, the acid may be added to a container containing the ash and heated.

The acid is not particularly limited as long as the acid can dissolve the ash. Among the acids that can dissolve the ash, an acid that does not dissolve the container (platinum dish, platinum crucible, inorganic glass container, etc.) used in the ashing step is preferable. Examples of such preferable acids include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, hydrogen peroxide solution, and perchloric acid, or mixed acids obtained by mixing two or more of these inorganic acids. By using an acid that does not dissolve the container used in the ashing step, the ash (that is, the ashed product) can be dissolved without mixing metal impurities derived from the container into the analysis solution. In addition, the acid is usually of a grade of reagent grade or higher. The acid may be an aqueous acid solution.

The acid concentration is not particularly limited, and a high concentration acid such as concentrated hydrochloric acid, concentrated nitric acid, concentrated sulfuric acid may be used as it is, or may be diluted with water. When the acid is used after being diluted, it is usually diluted with ion-exchanged water or ultrapure water (water having a specific resistance value of 18 MΩ · cm or more).

Further, the type of acid to be used may be appropriately selected according to the type of element that can be included in the sample (that is, the element to be measured), and an acid that can dissolve the element that can be included in the sample may be appropriately selected. .

The amount of acid used when dissolving the ashed product is not particularly limited as long as it can dissolve the entire amount of the ashed product, but is usually 10 to 500 times the amount of the ashed product. It is.

The dissolution temperature when the ash is dissolved in the acid (acid aqueous solution) is not particularly limited as long as it is not less than the freezing point and not more than the boiling point of the acid aqueous solution, but it must be 50 ° C. or more because it can be dissolved quickly. Is preferred. The said melting temperature can also be said to be a heating temperature when heating the container containing an ashed product and an acid. Examples of the apparatus used for heating include a heater and a hot plate.

The dissolution time when the ash is dissolved in the acid is not particularly limited as long as it can dissolve the entire amount of the ash. The dissolution time can also be said to be a heating time when the container containing the incinerated product and the acid is heated.

It can be confirmed by visual observation that the ashing product has been completely dissolved by the acid. Specifically, for example, by confirming that there is no residue, precipitation, or the like by visual inspection, or by visually confirming that precipitation does not occur after centrifugation, the dissolution of the ash by acid is completed. I can confirm.

The obtained ashed product aqueous solution may be diluted with ion-exchanged water or ultrapure water.

In the acid dissolution step in the present preparation method, it is possible to obtain an ash solution containing boron, phosphorus, and at least one element other than boron and phosphorus.

[Cation exchange resin contact process]
The cation exchange resin contact step captures the cation of the element derived from the scavenger on the cation exchange resin by bringing the ash exchange solution obtained in the acid dissolution step into contact with the cation exchange resin, and the cation exchange resin contacts the cation exchange resin. This is a step of obtaining an analysis solution containing an element other than an ionic element. The “cation element” is also referred to as a “capture target element” and is an element derived from a trapping agent.

In the cation exchange resin contact step, the cation of the element derived from the scavenger can be captured by the cation exchange resin by bringing the ash exchange solution obtained in the acid dissolution step into contact with the cation exchange resin. Thereby, in a cation exchange resin contact process, the analysis solution containing elements other than the element to be captured can be obtained. That is, the element in the sample that has been captured by the capture agent (for example, the oxide of the capture agent) is separated from the cation of the element derived from the capture agent to obtain an analysis solution containing the separated element. it can. In the cation exchange resin contact step, not all cations of the element derived from the scavenger need be captured by the cation exchange resin.

In this preparation method, when a calcium compound is included as a scavenger, the cation exchange resin contact step may have the following configuration. That is, the cation exchange resin contact step captures calcium ions contained in the above ash solution by capturing the cation exchange resin by bringing the ash exchange solution obtained in the acid dissolution step into contact with the cation exchange resin. And an analysis solution containing an element other than calcium ions.

The above-mentioned “analysis solution containing an element other than the capture target element” intends an analysis solution containing at least one kind of element other than the capture target element contained in the sample. . In other words, the analysis solution containing all elements other than the element to be captured contained in the sample is not intended. Specifically, the element contained in the analysis solution may be an element that is not captured by the cation exchange resin among the elements contained in the ash solution. In the cation exchange resin contact step, as an element that is not captured by the cation exchange resin, for example, [transition metal element] Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au; [boron group element] B, Al, Ga, In, Tl; [carbon group element] At least one element of Si, Ge, Sn, Pb; [Nictogen element] P, As, Sb, Bi; [Chalkogen element] S, Se, Te; Accordingly, the analysis solution may contain at least one of the listed elements.

In the cation exchange resin contact step in this preparation method, it is possible to obtain an analysis solution containing boron, phosphorus, and at least one element other than boron and phosphorus.

Specifically, in order to bring the ash product aqueous solution into contact with the cation exchange resin, for example, the ash product aqueous solution and the cation exchange resin may be mixed, or the column filled with the cation exchange resin may be ashed. An aqueous solution of a chemical compound may be passed therethrough. From the viewpoint of efficiently capturing the cation of the element derived from the scavenger in the aqueous solution of ash to the cation exchange resin, the cation exchange resin was filled as a method of contacting the aqueous solution of the ash and the cation exchange resin. A method of passing an aqueous ash product solution through the column is preferred.

The cation exchange resin is not particularly limited, and usually a granular or powdered one is used. Specific examples of the cation exchange resin include DOWEX strongly acidic cation exchange resin (H type), DOWEX-MARATHON (Na type) (manufactured by Dow Chemical Company), Diaion (manufactured by Mitsubishi Chemical Company), and the like. It is done.

The amount of cation exchange resin used is not particularly limited, and is determined based on the total exchange capacity of the cation exchange resin used.

When the ash exchange solution and the cation exchange resin are mixed, the cation exchange resin after mixing (in other words, after capturing the cation of the element derived from the scavenger in the sample) is a normal solid resin. It is separated from the incinerated aqueous solution by a liquid separation method. As a result, an analysis solution containing an element other than the element to be captured can be obtained as the ash solution after mixing with the cation exchange resin. Examples of the solid-liquid separation method include a gradient method, a centrifugal separation method, and a filtration method.

The cation exchange resin after separation from the ash product aqueous solution may be washed with water, but washing with water is not necessarily required. Usually, ion-exchanged water or ultrapure water is used for washing with water. When the cation exchange resin is washed with water, the cation exchange resin is separated from the washing water by performing the solid-liquid separation method again. The separated wash water can be mixed with the previously obtained analysis solution. By these operations related to water washing, elements other than the element to be captured can be more reliably recovered as an analysis solution.

When passing an aqueous solution of ashed product through a column filled with a cation exchange resin (also referred to as a cation exchange resin column), from the viewpoint of acid resistance, a column filled with cation exchange resin using quartz wool as a support is used. It is preferably used. The amount of quartz wool used as the support is not particularly limited, but is preferably 0.01 mass times to 0.1 mass times the cation exchange resin. Further, by using quartz wool as a support for the cation exchange resin column, it is possible to remove impurities contained in the column in the preliminary cleaning of the column.

When the ash exchange solution is passed through a column filled with a cation exchange resin (also referred to as a cation exchange resin column), the ash exchange solution after passing through the cation exchange resin column is used as an ash exchange solution other than the element to be captured. It is possible to obtain an analysis solution containing these elements. The cation exchange resin column after passing the ash product aqueous solution may be washed with ion-exchanged water or ultrapure water, but washing with water is not necessarily required. The wash water after passing through the cation exchange resin column can be mixed with the previously obtained analysis solution. By these operations related to water washing, elements other than the element to be captured can be more reliably recovered as an analysis solution.

In the cation exchange resin contact step, the contact temperature and contact time when the ash solution and the cation exchange resin are brought into contact with each other are not particularly limited. Examples of the contact temperature include the temperature of a cation exchange resin and the temperature of an incinerated aqueous solution. Examples of the contact time include the mixing time of the ash product aqueous solution and the cation exchange resin, and the flow rate of the ash product aqueous solution in the cation exchange resin column.

Another embodiment of the present invention provides an analysis method. An analysis method according to another embodiment of the present invention includes an analysis step of measuring an element contained in the analysis solution obtained by the preparation method with an analyzer.

In the present specification, “an analysis method according to another embodiment of the present invention” is also simply referred to as “the present analysis method”. The term “present analysis method” does not limit the analysis method in any way, but merely indicates one embodiment of the analysis method.

[Analysis process]
The analysis step is a step of measuring an element contained in the analysis solution obtained by the above-described preparation method with an analyzer. The above-mentioned “measuring an element with an analyzer” is intended to detect the element and specify its type, to quantify the element, or both.

In the analysis step according to an embodiment of the present invention, boron, phosphorus, and at least one element other than boron and phosphorus can be simultaneously measured by an analyzer.

As the analyzer, a known analyzer can be used. For example, an inductively coupled plasma mass spectrometer (ICP-MS), an inductively coupled plasma emission spectrometer (ICP-AES), an atomic absorption spectrometer (AAS) ) And the like. ICP-MS is a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS), triple quadrupole inductively coupled plasma-mass spectrometer (ICP-QQQ-MS), or high resolution type. An inductively coupled plasma mass spectrometer (double focused inductively coupled plasma mass spectrometer (HR-ICP-MS)) may be used.

In the analysis process, it is possible to measure the element by a known method as appropriate according to the analyzer used.

In the analysis process, it is intended to detect and quantify at least one of the elements contained in the analysis solution.

The analysis apparatus and measurement method in the analysis process may be appropriately selected according to the type of element to be measured.

[Effect of this preparation method]
Conventionally, as a method for preparing a sample for analysis to analyze a specific element, the element to be analyzed is captured and concentrated from an aqueous solution of an ash obtained by dissolving the ash in which the element in the sample is captured in an acid. The method of isolation was used. For example, in Patent Document 1, in order to analyze boron, a method is used in which boron is captured and concentrated from an ash solution using an anion exchange resin, and then isolated.

That is, in the conventional method, only the elements captured by the anion exchange resin can be measured, but in this preparation method, an analytical sample is prepared for measuring many elements contained in the sample at one time. be able to.

In this preparation method, the aqueous ash product obtained in the acid dissolution step is brought into contact with the cation exchange resin in the subsequent cation exchange resin contact step without any additional treatment (for example, pH adjustment). It is possible. On the other hand, as a conventional technique, for example, in Patent Document 1, before contacting the anodized aqueous solution obtained in the second step with an anion exchange resin in the third step, an ashed product is added by adding alkali to the incinerated aqueous solution. It is necessary to adjust the hydrogen concentration of the aqueous solution.

Further, in this preparation method, it is not necessary to wash the cation exchange resin after contacting with the ash solution in the cation exchange resin contact step. Even when the cation exchange resin after being brought into contact with the incinerated aqueous solution is washed, it is sufficient to wash the cation exchange resin (cation exchange resin column) once as described later in Examples. On the other hand, as a conventional technique, for example, in Patent Document 1, a cleaning operation for removing a substance other than an analysis target from an anion exchange resin brought into contact with an ash solution is very complicated.

Furthermore, in this preparation method, the ash product aqueous solution after contacting with the cation exchange resin in the cation exchange resin contact step of this preparation method is used as an analysis solution without any further special operation. It is possible to provide. On the other hand, as a conventional technique, for example, in Patent Document 1, boron to be analyzed is captured by an anion exchange resin in a third step. Therefore, it is necessary to elute boron trapped by the anion exchange resin in the subsequent fourth step with an acidic aqueous solution, and the obtained eluent is used for quantitative determination.

As described above, this preparation method makes it possible to easily analyze the elements contained in the sample as compared with the conventional method.

Furthermore, in this preparation method, since there are few steps (or operations), contamination of the final analysis sample (analysis solution) can be reduced. As a result, this preparation method achieves the same sensitivity as the conventional method that captures, concentrates and isolates the element to be analyzed, despite analyzing the remaining liquid that has captured the element that is not the object of analysis. Can do. In particular, the present preparation method can provide a sample for analysis that makes it possible to analyze boron and phosphorus with high sensitivity.

That is, the present preparation method can provide an analytical sample preparation method that enables simple analysis without limiting the elements contained in the sample to boron and / or phosphorus.

An embodiment of the present invention may have the following configuration.

[1] A method for preparing an analytical sample for analyzing an element contained in a sample, wherein the ash is obtained by ashing the sample in the presence of a scavenger to capture the element in the sample. An ashing step, and an ashing solution obtained by dissolving the ashing product obtained in the ashing step in an acid to obtain an ashing solution, and the ashing solution obtained in the acid dissolving step The cation exchange resin is contacted with the cation exchange resin to capture the cation of the element derived from the scavenger in the cation exchange resin, thereby obtaining an analysis solution containing an element other than the cation element. An exchange resin contact step, and a method for preparing a sample for analysis.

[2] The analytical sample preparation method according to [1], wherein the sample is a carbon-containing sample.

[3] An analysis comprising an analysis step of measuring an element contained in the analysis solution obtained by the method for preparing an analytical sample according to [1] or [2] with an analyzer Method.

An embodiment of the present invention will be described below.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to such examples.

Example 1
In Example 1, the following commercially available samples were used: N, N′-diphenyl-N, N′-di (m-tolyl) benzidine, pentacene, 5,5′-di (4-biphenylyl)- 2,2′-bithiophene, N, N′-dioctyl-3,4,9,10-perylenedicarboxymido, and 4,4′-bis (N-carbazolyl) -1,1′-biphenyl.

The sample for analysis was prepared based on the preparation method concerning one embodiment of the present invention using the above-mentioned sample. Subsequently, using the obtained analytical sample, elements (specifically, boron (B) and phosphorus (P) in the sample (analytical sample)) based on the analytical method according to one embodiment of the present invention. )) Was measured. The specific operation procedure is as follows. In Example 1, calcium carbonate was used as a scavenger.

(1. Ashing process)
A 10 mg powder sample was taken in a quartz beaker. Calcium carbonate (special grade reagent, powder) was added to the quartz beaker, and the sample and calcium carbonate were mixed to obtain a mixture thereof. Thereafter, the quartz beaker was heated with a burner to ash the mixture to obtain an ashed product.

(2. Acid dissolution process)
Ultrapure water (specific resistance value: 18 Ω · cm or more) and 20% by mass hydrochloric acid were added into the quartz beaker containing the obtained ashed product. Next, the quartz beaker was placed on a hot plate at 100 ° C. to 150 ° C. and heated to dissolve the ash, thereby obtaining an ash solution. Here, the concentration of hydrogen chloride in the ash solution was about 4% by mass.

(3. Cation exchange resin contact process)
Quartz wool and cation exchange resin (DOWEX strongly acidic cation exchange resin (H type); manufactured by Dow Chemical Co., Ltd.) are sequentially packed into a column to produce a cation exchange resin column (hereinafter also simply referred to as a column). did. The column was conditioned by passing 5% by mass hydrochloric acid and ultrapure water through the column.

Next, the ashed product aqueous solution obtained in the acid dissolution step was passed through the conditioned column, and the ashed product aqueous solution after passing through the column was recovered as an analysis solution. Further, ultrapure water was added to the quartz beaker containing the ash solution and the quartz beaker was washed, and the washed ultrapure water was passed through the column. The ultrapure water after passing through the column was collected and added to the analysis solution. Thereafter, ultrapure water was passed through the column to wash the column. Ultrapure water (washing liquid) after passing through the column was recovered and further added to the analysis solution.

20% by mass hydrochloric acid was added to the obtained analysis solution, and an analysis solution having a hydrogen chloride concentration of about 4% by mass was prepared using ultrapure water.

(4. Analysis process)
The analysis solution obtained in the cation exchange resin contact step is introduced into an inductively coupled plasma mass spectrometer (ICP-MS) (“ELAN DRCII”, manufactured by Perkin Elmer, USA, quadrupole inductively coupled plasma-mass spectrometer). Then, elements (specifically, boron (B) and phosphorus (P)) in the analysis solution were measured.

Table 1 shows the measurement results.

(Comparative Example 1: Element quantification by microwave decomposition method)
Using the same sample as used in Example 1, an analytical sample was prepared based on the conventional microwave decomposition method, and then the elements in the sample (specifically, boron (B) and Phosphorus (P)) was quantified. The specific operation procedure is as follows.

A 100 mg powder sample was collected in a microwave decomposition vessel made of fluororesin. Nitric acid (for ultra-trace analysis, Wako Pure Chemical Industries, Ltd.) was added to the vessel and sealed, followed by microwave decomposition. The decomposed sample solution was collected, and an analysis solution having a nitric acid concentration of about 25% by mass was prepared using ultrapure water.

The analysis solution obtained by the above microwave decomposition method is introduced into an inductively coupled plasma emission spectrometer (ICP-AES) (“iCAP6500”, manufactured by Thermo Fisher Scientific), and the elements in the analysis solution (specifically Boron (B) and phosphorus (P)) were measured.

The results are shown in Table 1.

* In Table 1, “B” represents boron, and “P” represents phosphorus.
* In Table 1, “<(numerical value)” was smaller than the numerical value (lower limit of quantification), indicating that quantification was not possible.

Table 1 shows the following. That is, in the microwave decomposition method, in many samples, the quantitative values of boron and phosphorus (particularly boron) were less than the lower limit of quantification and could not be accurately quantified. On the other hand, in this analysis method, boron and phosphorus (particularly phosphorus) could be accurately quantified in many samples even though the amount of the sample used was one-tenth that of the microwave decomposition method. I understood. From this, it was found that this analysis method can measure boron and phosphorus in a sample with a higher sensitivity in a smaller amount of sample than in the conventional method.

(Example 2)
In Example 2, a mixture was prepared by adding some elements to powdered ultra-high purity graphite, and the mixture was used as a sample. The elements added to the graphite were Ge, As, Te, and Re, and the amount of these elements added was 200 ng.

Using the sample (graphite), an analytical sample was prepared based on the preparation method according to an embodiment of the present invention. Subsequently, using the obtained analytical sample, the elements in the sample (analytical sample) were measured based on the analytical method according to one embodiment of the present invention. The specific operation procedure is as follows. In Example 2, calcium carbonate was used as the scavenger.

(1. Ashing process)
A 10 g powder sample was collected in a platinum dish. Calcium carbonate (special grade reagent, powder) was added to the platinum dish, and the sample and calcium carbonate were mixed to obtain a mixture thereof. Thereafter, the mixture was incinerated at 900 ° C. for 3 hours while oxygen was passed through the platinum dish at 3 L / min in an electric furnace to obtain an incinerated product.

(2. Acid dissolution process)
Ultrapure water (specific resistance value: 18 Ω · cm or more) and 20% by mass hydrochloric acid were added to the platinum dish containing the obtained ashed product. Next, the platinum dish was placed on a hot plate at 100 ° C., and the ashed product was dissolved by heating to obtain a ashed product aqueous solution. Here, the concentration of hydrogen chloride in the ash solution is about 4% by mass.

Next, the ashed product aqueous solution obtained in the acid dissolution step was passed through the conditioned column, and the ashed product aqueous solution after passing through the column was recovered as an analysis solution. Furthermore, ultrapure water was added to the platinum dish containing the incinerated aqueous solution to wash the platinum dish, and the washed ultrapure water was passed through the column. The ultrapure water after passing through the column was collected and added to the analysis solution. Thereafter, ultrapure water was passed through the column to wash the column. Ultrapure water (washing liquid) after passing through the column was recovered and further added to the analysis solution.

(4. Analysis process)
The analysis solution obtained in the cation exchange resin contact step is introduced into an inductively coupled plasma mass spectrometer (ICP-MS) (“ELAN DRCII”, manufactured by Perkin Elmer, USA, quadrupole inductively coupled plasma-mass spectrometer). Then, the elements in the analysis solution were measured.

The results are shown in Table 2.

In Table 2, “sample content” refers to the content of various elements contained in the ultra-high purity graphite itself used.

From Table 2, it was found that the present invention has an effect of providing an analytical sample capable of quantifying elements other than boron and phosphorus.

In the present invention, elements contained in a sample can be easily analyzed without being limited to boron and / or phosphorus. Therefore, the present invention can be used for analysis of elements contained in samples (raw materials, foods, etc.) in various fields such as semiconductor-related fields, medical device manufacturing fields, and food component analysis fields.

Claims

An analytical sample preparation method for analyzing an element contained in a sample,
An ashing step of ashing the sample in the presence of a scavenger to obtain an ash product in which the elements in the sample are captured;
An acid dissolution step of obtaining an aqueous solution of an ash by dissolving the ash obtained in the ashing step in an acid; and
By contacting the ash solution obtained in the acid dissolution step with a cation exchange resin, the cation of the element derived from the scavenger is captured on a cation exchange resin, and the cation exchange resin other than the cation element is used. A method for preparing a sample for analysis, comprising: a cation exchange resin contact step for obtaining an analysis solution containing an element.
The method for preparing a sample for analysis according to claim 1, wherein the sample is a carbon-containing sample.
3. An analysis method comprising an analysis step of measuring an element contained in the analysis solution obtained by the method for preparing an analysis sample according to claim 1 or 2 with an analyzer.