Element analysis apparatus, program for element analysis apparatus, and element analysis method

Abstract

To enable identification of a type of carbonate component contained in a sample.SOLUTION: An element analysis apparatus which comprises a heating furnace that heats a sample containing a carbonate component, and a gas analyzer that analyzes an analysis target gas generated from the heated sample, comprises: a temperature control part that raises a temperature of the heating furnace; a signal intensity acquisition part that acquires signal intensity data indicating a temporal change in signal intensity detected by the gas analyzer; a reference signal intensity storage part that stores in advance a plurality of pieces of reference signal intensity data indicating temporal changes in signal intensity of gases derived from carbonate components of known types; and a component analysis part that compares the acquired measured signal intensity data with the reference signal intensity data to identify a type of carbonate component contained in the sample.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an elemental analysis method and an elemental analysis device for analyzing elements such as carbon (C) and sulfur (S) contained in samples such as steel, non-ferrous metals, and ceramics. [Background technology]

[0002] One such elemental analyzer is one that introduces a vessel (boat) containing a sample into a heating furnace, where the sample is heated and combusted in the heating furnace, and analyzes the target gas produced from the heated and combusted sample. This elemental analyzer is configured to supply a combustion-supporting gas, such as oxygen gas, into the heating furnace to promote the combustion of the sample.

[0003] When analyzing a sample containing organic and inorganic carbon components with this elemental analyzer, the sample is placed in a heating furnace through which a combustion-supporting gas is flowing and analysis begins. As the sample burns, carbon dioxide derived from the inorganic carbon components is produced, and volatile organic carbon components are released from the sample. These components are detected in duplicate by the analyzer, making it difficult to quantitatively analyze each carbon component.

[0004] Patent Document 1 discloses an elemental analyzer that can separate and detect organic and inorganic carbon components contained in a sample by starting heating of the sample while an inert gas is being supplied as a carrier gas into a heating furnace, and then switching the carrier gas supplied into the heating furnace from the inert gas to a combustion-supporting gas. In other words, this elemental analyzer generates only volatile organic carbon components by heating the sample without burning it while supplying an inert gas, and then supplies a combustion-supporting gas to combust the sample, generating CO2 derived from the inorganic carbon components.

[0005] Patent Document 1 also describes that after the organic carbon components are detected, the temperature of the heating furnace can be increased to separate and detect the carbonate components contained in the sample from the inorganic carbon components produced by combustion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2023 / 112679 Summary of the Invention [Problem to be solved by the invention]

[0007] The elemental analyzer of Patent Document 1 described above can detect carbonate carbon components contained in a sample by separating them from organic carbon components and inorganic carbon components, but has the problem of not being able to determine what types of carbonate components are contained in the sample.

[0008] The present invention has been made in view of the above-mentioned problems, and its main object is to make it possible to identify the types of carbonate components contained in a sample. [Means for solving the problem]

[0009] That is, the elemental analysis apparatus of the present invention includes a heating furnace that heats a sample containing carbonate components, and a gas analyzer that analyzes a target gas generated from the heated sample, and is characterized by including: a temperature control unit that raises the temperature of the heating furnace; an actual signal intensity acquisition unit that acquires measured signal intensity data that indicates changes over time in signal intensity detected by the gas analyzer; a reference signal intensity storage unit that pre-stores multiple reference signal intensity data that indicate changes over time in signal intensity of gas derived from carbonate components of known types; and a component analysis unit that compares the acquired measured signal intensity data with the reference signal intensity data to identify the type of carbonate component contained in the sample.

[0010] In order to solve the above problems, the present inventors have focused on the fact that the thermal decomposition temperature differs depending on the type of carbonate component. That is, according to the configuration of the present invention, by raising the temperature of a heating furnace into which a sample has been placed, for example, when the sample contains multiple types of carbonate components, carbon dioxide gas derived from each carbonate component is generated from the sample at different times, and the signal intensity peaks of the respective carbonate components can be detected separately in the gas analyzer. Furthermore, since information on reference signal intensities that indicates changes over time in the signal intensity of gas derived from carbonate components of known types is pre-stored, the types of carbonate components contained in the sample can be identified by comparing the information on measured signal intensities acquired by the gas analyzer with the stored reference signal intensity information.

[0011] In the elemental analyzer, it is preferable that each of the plurality of reference signal intensity data indicates a change over time in signal intensity detected by the gas analyzer while a reference sample containing one type of carbonate component is heated in the heating furnace. This makes it easier to compare the measured signal intensity data obtained by heating the sample to be analyzed, making it easier to identify the type of carbonate component more accurately.

[0012] Furthermore, it is preferable that the reference sample in the elemental analysis apparatus has a known content of carbonate components, and the component analysis unit compares the measured signal intensity data with the reference signal intensity data to quantify the carbonate components contained in the sample by type. In this way, by comparing the peak data with that created using a reference sample with a known carbonate component content, the weight and other details of the carbonate components contained in the sample to be analyzed can be measured for each type.

[0013] Furthermore, it is preferable that the reference signal intensity data and the measured signal intensity data are obtained under the same heating conditions in the elemental analyzer. This makes it easier to compare the signal intensity data with each other, making it easier to identify the type of carbonate component more accurately.

[0014] In a specific embodiment of the elemental analyzer, the temperature control unit raises the temperature of the heating furnace while an inert gas is being supplied into the heating furnace as a carrier gas. This allows for easy pyrolysis of carbonate components at a targeted temperature without burning the sample, facilitating comparison with reference signal intensity data. Furthermore, if the sample contains inorganic carbon components, switching the carrier gas to a combustion-supporting gas after the pyrolysis of carbonate carbon is complete allows for the detection of only the inorganic carbon components.

[0015] The program for an elemental analyzer of the present invention is a program for an elemental analyzer equipped with a heating furnace for heating a sample containing carbonate components and a gas analyzer for analyzing a target gas generated from the heated sample, and is characterized in that it causes a computer to function as a temperature control unit for raising the temperature of the heating furnace, a signal intensity acquisition unit for acquiring signal intensity data showing changes over time in the signal intensity detected by the gas analyzer, a reference signal intensity storage unit for storing in advance a plurality of reference signal intensity data showing changes over time in the signal intensity of gas derived from carbonate components of known types, and a component analysis unit for comparing the acquired measured signal intensity data with the reference signal intensity data to identify the type of carbonate component contained in the sample.

[0016] The elemental analysis method of the present invention is an elemental analysis method in which a sample containing a carbonate component is heated in a heating furnace and the target gas produced from the heated sample is analyzed with a gas analyzer, and is characterized by including: a heating step of raising the temperature of the heating furnace into which the sample has been placed; a signal intensity acquisition step of acquiring signal intensity data showing changes over time in the signal intensity detected by the gas analyzer; a reference signal intensity storage step of pre-storing a plurality of reference signal intensity data showing changes over time in the signal intensity of gas derived from carbonate components of known types; and a component analysis step of comparing the acquired actual signal intensity data with the reference signal intensity data to identify the type of carbonate component contained in the sample.

[0017] Such an elemental analysis program and elemental analysis method can achieve the same effects as those of the elemental analysis apparatus described above. [Effects of the Invention]

[0018] According to the present invention configured in this way, it is possible to identify the type of carbonate component contained in a sample. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram schematically illustrating the configuration of an elemental analyzer according to an embodiment of the present invention. [Figure 2] FIG. 2 is a functional block diagram of the elemental analyzer of the embodiment. [Figure 3] 4 is a flowchart illustrating an example of an analysis operation of the elemental analyzer of the embodiment. [Figure 4] FIG. 2 is a schematic diagram illustrating an analysis operation of the elemental analyzer of the embodiment. [Figure 5] FIG. 3 is a diagram showing an example of a signal intensity profile detected by a gas analyzer of the elemental analyzer of the embodiment. [Figure 6] FIG. 2 is a diagram showing an example of a signal intensity profile of a gas derived from a carbonate component detected by a gas analyzer of the elemental analyzer, and a signal intensity profile indicated by reference signal intensity data. [Figure 7] FIG. 10 is a diagram showing an example of a signal intensity profile detected by a gas analyzer of another embodiment of the elemental analyzer. [Figure 8] FIG. 10 is a diagram showing an example of a signal intensity profile detected by a gas analyzer of another embodiment of the elemental analyzer. [Figure 9] FIG. 10 is a diagram showing an example of a signal intensity profile detected by a gas analyzer of another embodiment of the elemental analyzer. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] <Device configuration> The elemental analyzer 100 of this embodiment is for heating and burning a powdered or bulk solid sample S, for example, and analyzing elements such as carbon (C) and sulfur (S) contained in the sample S from the resulting gas. Examples of samples include those containing inorganic materials such as steel or non-ferrous metals, those containing organic materials such as coal, and those containing both inorganic and organic materials. In this embodiment, the sample contains at least multiple types of carbonate components and further contains organic carbon components and inorganic carbon components.

[0022] Specifically, as shown in FIG. 1, this elemental analysis apparatus 100 includes a heating furnace 1 in which a container V containing a sample S is placed, a gas analyzer 2 that analyzes the gas (also referred to as the analysis target gas) produced from the sample S heated and combusted in the heating furnace 1, a carrier gas supply mechanism 3 that supplies a carrier gas into the heating furnace 1, and a control device C.

[0023] The container V contains, for example, a powdered sample S. The container V in this embodiment is an elongated container having an opening at the top, and is specifically a porcelain combustion boat, a ceramic board, a quartz board, or the like. Note that the shape of the container V is not limited to this, and various shapes are possible.

[0024] The heating furnace 1 is a tubular furnace having a heating space 1s inside into which a container V is put in and taken out. In this heating space 1s, a container V that does not contain a sample S is baked empty, or a container V that contains a sample S is heated, thereby heating the sample S and generating gas.

[0025] 1, the heating furnace 1 comprises a furnace body 11 that forms a heating space 1s extending horizontally, an electric resistor 12 that is provided around the furnace body 11 and heats the furnace body 11, and a power supply circuit (not shown) that supplies power to the electric resistor 12 to generate heat. The heating furnace 1 is configured so that the temperature of the furnace body 11 (temperature inside the furnace) can be set as desired, and the current value of the temperature inside the furnace can be measured by a temperature sensor such as a thermocouple.

[0026] The furnace body 11 is a tubular (straight) ceramic molded body, and at one end along the tube axis, an opening (sample inlet / outlet) 1p is formed for introducing a container V into the heating space 1s. At the other end of the furnace body 11, a gas outlet 1q is formed for introducing gas generated from the sample S to the gas analyzer 2. The furnace body 11 may be heated by passing an electric current through an electric resistance furnace to cause resistance heating (Joule heating), in which case the furnace body 11 is made of a conductive metal. Alternatively, the container V or sample S housed in the furnace body 11 may be induction heated.

[0027] An opening / closing lid 13 is provided at the opening 1p of the furnace body 11. The opening / closing lid 13 moves between a closed position where it closes the opening 1p and an open position where it opens the opening 1p, and is driven by an actuator such as an air cylinder.

[0028] A front chamber 4s is provided in front of the heating furnace 1 to store the containers V before they are loaded into the heating furnace 1. The front chamber 4s is formed by the internal space of a box-shaped housing 4, and is configured to communicate with an opening 1p of the heating furnace 1 via an opening / closing lid 13. An inert gas filling flow path L5 through which an inert gas such as nitrogen gas flows and an exhaust flow path (not shown) are connected to the front chamber 4s, so that the air in the front chamber 4s can be replaced with the inert gas.

[0029] The gas analyzer 2 analyzes the gas generated in the heating furnace 1 to determine the content of each component contained in the sample S. In this embodiment, the analysis is performed using, for example, a non-dispersive infrared absorption method (NDIR method). Specifically, the gas analyzer 2 has a non-dispersive infrared detector (not shown) and detects CO2, CO, SO2, etc. contained in the gas discharged from the gas discharge port 1q of the heating furnace 1 to determine the content of carbon (C), sulfur (S), etc. contained in the sample S. Specifically, the gas analyzer 2 detects the gas to be analyzed introduced from a gas inlet (not shown), measures the signal intensity over time, and outputs the signal intensity to the control device C.

[0030] The gas analyzer 2 is connected to the gas outlet 1q of the heating furnace 1. The gas analyzer 2 is provided on the gas outlet flow path L1, and a dust filter 5, a dehydrating agent 6, etc. are provided on the upstream side of the gas analyzer 2 on this gas outlet flow path L1.

[0031] The carrier gas supply mechanism 3 switchably supplies different types of carrier gas (specifically, a combustion-supporting gas and an inert gas) into the heating furnace 1. Specifically, the carrier gas supply mechanism 3 includes a combustion-supporting gas supply source 31, an inert gas supply source 32, a carrier gas supply flow path L2 that supplies the carrier gas into the heating furnace 1, a combustion-supporting gas introduction flow path L3 that connects the combustion-supporting gas supply source 31 and the carrier gas supply flow path L2, an inert gas introduction flow path L4 that connects the inert gas supply source 32 and the carrier gas supply flow path L2, and a switching mechanism 33 that switches the connection destination of the carrier gas supply flow path L2 between the combustion-supporting gas introduction flow path L3 and the inert gas introduction flow path L4.

[0032] The combustion-stimulating gas supply source 31 is for feeding the combustion-stimulating gas into the combustion-stimulating gas introduction path L3, and specifically includes a gas cylinder filled with the combustion-stimulating gas, a regulator attached to the gas cylinder, etc. This combustion-stimulating gas promotes the combustion of the sample in the heating furnace 1, and specifically is O2 (oxygen) gas.

[0033] The inert gas supply source 32 is for supplying an inert gas to the inert gas introduction path L4, and specifically includes a gas cylinder filled with the inert gas, a regulator attached to the gas cylinder, etc. This inert gas is specifically N2 (nitrogen) gas, Ar (argon gas), He (helium) gas, etc.

[0034] The carrier gas supply passage L2 has a starting end connected to the combustion-supporting gas introduction passage L3 and the inert gas introduction passage L4, and a terminal end connected to the furnace body 11 of the heating furnace 1 and communicating with the heating space 1s.

[0035] In this embodiment, the switching mechanism 33 is provided at the connection point between the carrier gas supply passage L2 and the combustion-supporting gas introduction passage L3 and the inert gas introduction passage L4. The switching mechanism 33 is a three-way valve or the like that selectively opens and closes the combustion-supporting gas introduction passage L3 and the inert gas introduction passage L4.

[0036] The control device C is a general-purpose or dedicated computer equipped with a CPU, memory, input / output interface, etc. This control device C functions as a temperature control unit C1, a measured signal intensity acquisition unit C2, and a component analysis unit C3 by causing the CPU and peripheral devices to cooperate in accordance with a predetermined program stored in a predetermined area of ​​the memory, as shown in Fig. 2.

[0037] The temperature control unit C1 outputs a control signal to the power supply circuit of the heating furnace 1 to control the temperature (furnace temperature) of the furnace body 11. In this embodiment, the temperature control unit C1 is configured to heat the inside of the furnace at a predetermined first set temperature for a certain period of time, and then raise the temperature to a predetermined second set temperature at a substantially constant heating rate.

[0038] The measured signal strength acquisition unit C2 acquires measured signal strength data that indicates the change over time in the signal strength detected by the gas analyzer 2, and outputs the data to the component analysis unit C3. Specifically, this measured signal strength data is a signal strength profile with the horizontal axis representing time and the vertical axis representing signal strength.

[0039] The component analysis unit C3 calculates the content of each component contained in the sample S based on the acquired measured signal intensity data.

[0040] Thus, in the gas analyzer 2 of this embodiment, as shown in FIG. 2, the control device C further functions as a reference signal intensity storage unit C4.

[0041] The reference signal intensity storage unit C4 stores in advance a plurality of reference signal intensity data indicating the change over time in the signal intensity of a gas (specifically, carbon dioxide gas) derived from a carbonate component whose type is known. Examples of carbonate components whose type is known include, but are not limited to, calcium carbonate, potassium carbonate, sodium bicarbonate, magnesium carbonate, etc.

[0042] Specifically, each of these reference signal intensity data was obtained by heating a reference sample containing a known amount of one carbonate component in a heating furnace 1 and detecting the evolved gas with a gas analyzer 2. Specifically, each of these reference signal intensity data is a signal intensity profile, with the horizontal axis representing time and the vertical axis representing signal intensity, showing the change in signal intensity detected by the gas analyzer 2 during heating of a reference sample containing one carbonate component in a heating furnace 1, as illustrated in FIG. 6 . More specifically, this reference signal intensity data was obtained under substantially the same heating conditions as the measured signal intensity data, and further, was obtained by supplying the same type and flow rate of carrier gas into the heating furnace 1. Note that FIG. 6 shows signal intensity profiles of carbon dioxide gas derived from each of the carbonate components calcium carbonate, magnesium carbonate, potassium carbonate, and sodium bicarbonate as the reference signal intensity data, and shows signal intensity profiles of samples containing calcium carbonate and potassium carbonate as the measured signal intensity data.

[0043] The component analysis unit C3 then compares the measured signal intensity data acquired by the measured signal intensity acquisition unit C2 with the reference signal intensity data stored in the reference signal intensity data storage unit C4 to identify the type of carbonate component contained in the sample. More specifically, the component analysis unit C3 compares the signal intensity profile indicated by the measured signal intensity data (measured signal intensity profile) with the signal intensity profile indicated by each of the multiple peak data (reference signal intensity profile) to identify the type of carbonate component contained in the sample S. As a method for doing so, for example, the component analysis unit C3 may overlay each of the reference signal intensity profiles while changing the ratio so that the degree of similarity compared with the measured signal intensity profile is equal to or greater than a threshold, and identify the type of carbonate component based on the result.

[0044] Furthermore, the component analysis unit C3 compares the measured signal intensity profile with a plurality of reference signal intensity profiles to quantify the content of each type of carbonate component contained in the sample S. For example, the component analysis unit C3 may calculate the total amount of carbon components contained in the sample S from the overall area indicated by the measured signal intensity profile, and then quantify each type of carbonate carbon component from the area ratio of the signal intensity profiles derived from each carbon component.

[0045] <Analysis method> Next, an example of an elemental analysis operation using the elemental analysis apparatus 100 of this embodiment will be described with reference to FIGS.

[0046] 4(a), the sample S contained in the container V is placed in the front chamber 4s, and an inert gas (such as N2 gas) is supplied into the front chamber 4s from the inert gas filling channel L5 to replace the air in the front chamber 4s with the inert gas (step S1). In this step, the opening / closing lid 13 is in the closed position.

[0047] Next, the heating furnace 1 is operated using an operation panel or the like to set the temperature of the furnace body 11 to a predetermined first set temperature, and the inside of the furnace body 11 is heated (step S2). This first set temperature is preferably 100°C or higher and 700°C or lower, and more preferably 200°C or higher and 500°C or lower. By setting the first set temperature within this range, volatile organic carbon components contained in the sample S can be separated and extracted from carbonate components and inorganic carbon components in a later step.

[0048] 4(b), an inert gas (such as N2 gas) is supplied as a carrier gas from the carrier gas supply passage L2 into the furnace body 11 (step S3). The supply flow rate of the inert gas from the carrier gas supply passage L2 is, for example, 1 L / min to 5 L / min, but is not limited thereto. The order of steps S1 to S3 may be reversed.

[0049] Then, when the temperature inside the furnace measured by the temperature sensor stabilizes near the first set temperature (for example, within ±1°C), as shown in Figure 4(c), the open / close lid 13 is moved to the open position to open the sample inlet / outlet 1p of the furnace body 11, and the container V containing the sample S is pushed out and moved from the front chamber 4s into the heating space 1s using a metal rod or the like (step S4). Here, while the container V is being moved, it is preferable to continue supplying inert gas from the inert gas filling channel L5 into the front chamber 4s.

[0050] After the container V containing the sample S is moved into the heating space 1s, the open / close lid 13 is moved to the closed position as shown in FIG. 4(d), and the sample inlet / outlet 1p of the furnace body 11 is closed. Soon after, organic carbon components volatilize from the heated sample S, and an intensity signal attributable to the organic carbon components is detected in the gas analyzer 2, as shown in FIG. 5. In this step, it is preferable to maintain the set temperature of the furnace body 11 constant from the time the sample inlet / outlet 1p is closed until a peak value of the intensity signal attributable to the organic carbon components is detected in the gas analyzer 2, preferably until the peak value of the intensity signal attributable to the organic carbon components is no longer detected. Furthermore, in this step, only an inert gas is continuously flowed as the carrier gas supplied to the furnace body 11, without any combustion-supporting gas.

[0051] Next, the heating furnace 1 is operated via an operation panel or the like to change the set temperature of the furnace body 11 to a second set temperature higher than the first set temperature, thereby increasing the temperature inside the furnace body 11 (step S5). The change from the first set temperature to the second set temperature is preferably performed at least after the gas analyzer 2 detects a peak value of the signal intensity attributable to the organic carbon component, and more preferably after the gas analyzer 2 no longer detects the signal intensity attributable to the organic carbon component. This second set temperature may be any temperature at which the inorganic carbon component contained in the sample burns, and is preferably, for example, between 800°C and 1500°C, and more preferably between 1000°C and 1200°C. By setting the second set temperature within this range, the carbonate carbon component contained in the sample can be extracted separately from the organic carbon component and the inorganic carbon component. The temperature increase rate is not particularly limited, but is preferably between 0.1°C / sec and 1°C / sec. A slower temperature increase rate is preferable to facilitate resolution of the signal intensity peak.

[0052] When the temperature increase of the furnace body 11 starts, as shown in FIG. 4(e), the multiple types of carbonate components contained in the sample S are thermally decomposed in sequence to generate CO2. Then, as shown in FIG. 5, an intensity signal derived from the carbonate components is detected in the gas analyzer 2. In this embodiment, as the temperature increases, multiple peak values ​​of the intensity signal derived from the carbonate components are detected. In this process, only an inert gas is continuously supplied as the carrier gas to be supplied into the furnace body 11, without supplying any combustion-supporting gas, at least from the start of the temperature increase of the furnace body 11 until the peak values ​​of the intensity signal derived from the carbonate components are no longer detected in the gas analyzer 2.

[0053] Next, the switching mechanism 33 is operated to switch the carrier gas supplied from the carrier gas supply line L2 into the furnace body 11 from an inert gas (N2) to a combustion-supporting gas (O2) (step S6), as shown in FIG. 4(f). This carrier gas switch is preferably performed at least after the gas analyzer 2 no longer detects a signal intensity derived from carbonate carbon components, and more preferably after the furnace temperature of the furnace body 11 reaches 1000°C or higher. Shortly after the carrier gas is switched to the combustion-supporting gas, the sample S is combusted to generate CO2, and as shown in FIG. 5, an intensity signal derived from inorganic carbon components is detected in the gas analyzer 2. In this step, the set temperature of the furnace body 11 may be maintained at the second set temperature or may be increased. The supply flow rate of the combustion-supporting gas from the carrier gas supply line L2 may be the same as or different from the supply flow rate of the inert gas in the previous step. The supply flow rate of the combustion-supporting gas is, for example, 1 L / min to 5 L / min, but is not limited thereto.

[0054] According to the elemental analysis apparatus 100 of this embodiment configured as described above, heating of the sample S is started first while an inert gas is being supplied as a carrier gas into the heating furnace 11. Therefore, the sample S does not burn and produce CO2 derived from inorganic carbon components, but only generates volatile organic carbon components, which can be detected by the gas analyzer 2.

[0055] Then, after the signal intensity of the gas to be analyzed detected by the gas analyzer 2 increases and reaches the first peak value (i.e., after the organic carbon components are detected by the gas analyzer 2), the heating furnace 1 is heated while an inert gas is flowing as a carrier gas, so that the carbonate components contained in the sample S can be detected separately from the organic carbon components and inorganic carbon components.

[0056] Furthermore, as the temperature of the heating furnace 1 increases, multiple types of carbonate components with different thermal decomposition temperatures are generated from the sample at different times, and the signal intensity peaks of each component can be separated and detected by the gas analyzer 2. The reference signal intensity memory unit C4 pre-stores a reference signal intensity profile that indicates the change over time in the signal intensity of gas derived from carbonate components whose types are known. Therefore, by comparing the measured signal intensity profile acquired by the gas analyzer 2 with the stored reference signal intensity profile, the types of carbonate components contained in the sample S can be identified and the amount of each type of carbonate component can be determined.

[0057] Then, the carrier gas supplied to the heating furnace 1 is switched to a combustion-supporting gas to start combustion of the sample S, thereby generating CO 2 derived from inorganic carbon components, which can be detected by the gas analyzer 2.

[0058] <Other embodiments> The present invention is not limited to the above-described embodiment. For example, in the elemental analyzer 100 of the above embodiment, the antechamber 4 is provided in front of the heating furnace 1, but this is not limited thereto. In other embodiments of the elemental analyzer 100, the antechamber 4 may not be provided, and the sample S contained in the container V may be placed in an air atmosphere and then introduced into the furnace body 11.

[0059] In another embodiment, the inert gas supplied to the furnace body 11 as a carrier gas may contain an inert gas component with a concentration of 99% or more, and may be a gas containing multiple components (such as O2) in addition to a single component gas such as N2 gas. In this case, if the O2 concentration is high, the sample will not be steamed and will be oxidized, so the O2 concentration is preferably 100 ppm or less.

[0060] Similarly, in another embodiment, the combustion-stimulating gas supplied to the furnace body 11 as a carrier gas may contain an O2 concentration equal to or higher than that of air, and may be a gas containing multiple components (e.g., CO2, etc.) rather than a single component gas such as O2. In this case, when analyzing carbon contained in a sample, it is preferable that the CO2 concentration in the combustion-stimulating gas is low, specifically, a CO2 concentration of 100 ppm or less. In addition, the combustion-stimulating gas may contain an inert gas component.

[0061] In the above embodiment, the temperature control unit C1 is configured to raise the temperature of the heating furnace 1 at a constant rate, but this is not limited to this. In another embodiment, as shown in Fig. 7, the temperature control unit C1 may store in advance one or more temperatures at which carbonates thermally decompose, and maintain the temperature for a certain period of time.

[0062] Furthermore, in the above embodiment, after the organic carbon components are detected by the gas analyzer 2, the temperature is raised while the inert gas is being supplied as the carrier gas. However, this is not limited to this. In another embodiment, as shown in Fig. 8, after the organic carbon components are detected by the gas analyzer 2, the carrier gas to be supplied may be switched from the inert gas to a combustion-supporting gas before the temperature is raised. This also makes it possible to separately detect the organic carbon components and the carbonate components.

[0063] Furthermore, although the component analysis unit C3 in the above embodiment performs both qualitative and quantitative analysis of carbonate components, this is not limiting. In other embodiments, the component analysis unit C3 may be configured to perform only qualitative analysis without performing quantitative analysis.

[0064] In the above embodiment, the sample analyzed contains not only carbonate components but also organic and inorganic carbon components. However, this is not limiting. In other embodiments, the sample may contain carbonate components but not organic or inorganic carbon components. In this case, as shown in FIG. 9, the temperature of the heating furnace 1 may be raised immediately after the sample S is placed in the heating furnace 1, without maintaining the furnace temperature at the first and second set temperatures.

[0065] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0066] 100...Elemental analyzer 1...Heating furnace 11 Furnace body 2 Gas analyzer V...container S... Sample

Claims

1. An elemental analyzer comprising: a heating furnace for heating a sample containing a carbonate component; and a gas analyzer for analyzing an analysis target gas generated from the heated sample, a temperature control unit that increases the temperature of the heating furnace; an actual signal strength acquisition unit that acquires actual signal strength data that indicates a change over time in signal strength detected by the gas analyzer; a reference signal intensity storage unit that stores in advance a plurality of reference signal intensity data indicating time-dependent changes in signal intensity of gas derived from carbonate components whose types are known; an elemental analyzer comprising: a component analysis unit that compares the acquired actual signal intensity data with the reference signal intensity data to identify the type of carbonate component contained in the sample.

2. 2. The elemental analyzer according to claim 1, wherein each of the plurality of reference signal intensity data indicates a change over time in signal intensity detected by the gas analyzer while a reference sample containing one type of carbonate component is heated in the heating furnace.

3. The reference sample has a known carbonate content, 3. The elemental analyzer according to claim 2, wherein the component analysis unit compares the measured signal intensity data with the reference signal intensity data to quantify the carbonate components contained in the sample by type.

4. 4. The elemental analyzer according to claim 2, wherein the reference signal intensity data and the measured signal intensity data are obtained under the same heating conditions.

5. 5. The elemental analyzer according to claim 1, wherein the temperature control unit raises the temperature of the heating furnace while an inert gas is supplied into the heating furnace as a carrier gas.

6. A program for an elemental analyzer including a heating furnace for heating a sample containing a carbonate component and a gas analyzer for analyzing an analysis target gas generated from the heated sample, a temperature control unit that increases the temperature of the heating furnace; a signal strength acquisition unit that acquires signal strength data indicating a change over time in signal strength detected by the gas analyzer; a reference signal intensity storage unit that stores in advance a plurality of reference signal intensity data indicating time-dependent changes in signal intensity of gas derived from carbonate components whose types are known; A program for an elemental analyzer that causes a computer to function as a component analysis unit that compares the acquired actual signal intensity data with the reference signal intensity data to identify the type of carbonate component contained in the sample.

7. 1. An elemental analysis method comprising heating a sample containing a carbonate component in a heating furnace and analyzing an analysis target gas generated from the heated sample with a gas analyzer, a temperature raising step of raising the temperature of the heating furnace into which the sample has been placed; a signal intensity acquisition step of acquiring signal intensity data indicating a change over time in the signal intensity detected by the gas analyzer; a reference signal intensity storage step of storing in advance a plurality of reference signal intensity data indicating a time-dependent change in signal intensity of a gas derived from a carbonate component whose type is known; a component analysis step of comparing the acquired actual signal intensity data with the reference signal intensity data to identify the type of carbonate component contained in the sample.

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