JP2020106278A - Combustion type carbon analysis device and carbon analysis method - Google Patents

Abstract

To measure accurately and efficiently the total amount of carbon contained in a sample.SOLUTION: A combustion type carbon analysis device 1 includes: a combustion chamber 16 into which a sample 11 is introduced; an oxygen gas supply unit 18 for supplying oxygen gas into the combustion chamber 16; a heating unit 15 for heating the inside of the combustion chamber 16; a measuring unit 50 for measuring an amount of carbon dioxide contained in the gas released from the combustion chamber 16; and an oxygen concentration measuring unit 160 provided in the gas flow path from a sample introduction position in the combustion chamber 16 to the measurement unit 50.SELECTED DRAWING: Figure 1

Description

The present invention relates to a combustion type carbon analyzer and a carbon analysis method for measuring the amount of total carbon (TC: Total Carbon) contained in a liquid sample or a solid sample.

A combustion-type carbon analyzer is used as a device for measuring the amount of carbon contained in liquid samples such as river water, lake water, and factory wastewater, and solid samples such as soil and food (for example, Patent Document 1). In the combustion type carbon analyzer, a liquid sample or a solid sample to be analyzed is introduced into a combustion chamber and heated to about 900° C. while supplying oxygen gas to burn the sample. Then, the carbon dioxide generated by the combustion of carbon contained in the sample is introduced into a non-dispersive infrared spectrometer (NDIR) to measure the amount of carbon dioxide based on the light absorption. After the start of combustion of the sample, the measurement is terminated when carbon dioxide is no longer detected, and the total amount of carbon in the sample is obtained based on the integrated value of the measured amount of carbon dioxide.

JP, 2014-132236, A JP, 2007-263933, A JP, 2008-008666, A

"Measurement Tips. A Story of Zirconia Oxygen Analyzer", [online], MS TD July 1994 issue, [November 26, 2018 search], Internet <URL: http://www.m- system.co.jp/mstoday/plan/mame/b_sensor/9407/index.html>

In the combustion carbon analyzer, oxygen gas is supplied to the combustion chamber at a predetermined constant flow rate, but the supply amount of the oxygen gas is not always sufficient to burn carbon contained in the sample. .. If the amount of oxygen supplied to the combustion chamber is insufficient, the sample may incompletely burn and carbon monoxide may be generated. In a combustion carbon analyzer, the amount of carbon dioxide is measured on the premise that the sample is completely combusted, and the total amount of carbon is calculated from the integrated value.Therefore, when carbon monoxide is generated, the total amount of carbon in the sample is calculated. Is less than the total amount of carbon actually contained in the sample. In addition, if the amount of oxygen supplied to the combustion chamber is insufficient, it takes time to burn the sample and the measurement time becomes long even if carbon monoxide is not generated.

The problem to be solved by the present invention is to provide a combustion type carbon analyzer capable of accurately and efficiently measuring the total amount of carbon contained in a sample.

Combustion carbon analyzer according to the present invention made to solve the above problems,
A combustion chamber into which the sample is introduced,
An oxygen gas supply unit for supplying oxygen gas into the combustion chamber,
A heating unit for heating the combustion chamber,
A measuring unit for measuring the amount of carbon dioxide contained in the gas released from the combustion chamber,
An oxygen concentration measuring unit provided in a gas flow path from the sample introduction position in the combustion chamber to the measuring unit.

Further, the carbon analysis method according to the present invention made to solve the above problems,
A sample introduction step of introducing a sample into a predetermined position in the combustion chamber,
An oxygen gas supply step of supplying oxygen gas into the combustion chamber,
Measuring the amount of carbon dioxide contained in the gas released from the combustion chamber while heating the combustion chamber, and measuring the concentration of oxygen gas after passing through the predetermined position.

In the combustion-type carbon analyzer and carbon analysis method according to the present invention, the oxygen is supplied to the combustion chamber to heat the sample to burn the sample, and the gas from the introduction position of the sample (predetermined position in the combustion chamber) to the measurement unit Measure the oxygen concentration in the channel. If the measured oxygen concentration is low (for example, close to 0), the oxygen gas supplied to the combustion chamber is completely consumed by the sample combustion, and there is a high possibility that the oxygen gas supply amount is insufficient. .. In the combustion-type carbon analyzer and carbon analysis method according to the present invention, it can be confirmed based on the measured value of the oxygen concentration whether the amount of oxygen supplied to the combustion chamber is sufficient for burning the sample. When the amount of oxygen is insufficient, the total amount of carbon contained in the sample can be measured accurately and efficiently by increasing the supply amount of oxygen gas and completely burning the sample. ..

The principal part lineblock diagram of one example of the combustion type carbon analysis device concerning the present invention. The elements on larger scale of the combustion pipe for all carbon combustion which the combustion-type carbon analyzer of a present Example has.

An embodiment of a combustion-type carbon analyzer and a carbon analysis method according to the present invention will be described below with reference to the drawings. The combustion-type carbon analyzer 1 and the carbon analysis method of this example are used to measure the amount of carbon contained in a solid sample or a liquid sample.

The combustion type carbon analyzer 1 of the present embodiment includes an all carbon combustion unit 10, an inorganic carbon combustion unit 20, a detector 50, and a control unit 100. In the combustion-type carbon analyzer 1 of the present embodiment, the total carbon amount is measured by burning the sample 11 in the total carbon combustion unit 10 and the inorganic carbon combustion unit 20 and measuring the amount of generated carbon dioxide with the detector 50. And the amount of inorganic carbon can be determined. Further, the organic carbon amount can be obtained by subtracting the inorganic carbon amount from the total carbon amount.

The control unit 100 includes a storage unit 101 and a measurement control unit 102 that is a functional block. The control unit 100 is a general computer, and the measurement control unit 102 is embodied by executing a program installed in advance by a processor. The measurement control unit 102 controls the operation of each unit related to measurement. The storage unit 101 stores a conversion table for converting an output signal from a voltmeter 163 of the oximeter 160 described later into an oxygen concentration.

The all-carbon combustion unit 10 has a first sample port moving rod 13 provided with a sample port 131 at its tip. By operating the first sample port moving rod 13, the sample port 131 can be moved between the first sample introduction chamber 14 and the first combustion pipe 16. The first sample introduction chamber 14 is provided with a lid 141 on the upper portion, and by removing the lid 141, the tray 12 containing the sample 11 can be set in the sample port 131. Pure oxygen gas (hereinafter referred to as “oxygen gas”) is supplied to the first combustion pipe 16 from the oxygen cylinder 18 through the first sample introduction chamber 14. The flow rate of the oxygen gas is adjusted by the flow rate adjusting unit 181. The sample port 131 and the tray 12 are made of a heat resistant material. One example of a heat resistant material is ceramic.

The first combustion pipe 16 is arranged in the first combustion furnace 15. The first combustion pipe 16 is a tubular member made of an oxygen-conducting solid electrolyte, and its tip end is tapered. The oxygen conducting solid electrolyte is, for example, stabilized zirconia. Stabilized zirconia is obtained by adding yttria Y ₂ O ₃ or the like as a stabilizer to zirconia (zirconia oxide ZrO ₂ ) which is the main component. Further, the tip of the first combustion pipe 16 is attached to a first pipe connecting portion 19 provided outside the first combustion furnace 15. Further, an oxidation catalyst 17 is arranged at the tip of the first combustion pipe 16 in order to prevent soot from being generated when the sample 11 burns. As the oxidation catalyst, for example, cobalt oxide is used. In use, the first combustion furnace 15 is heated to 900° C., for example. Further, the stabilized zirconia to which magnesium oxide MgO or the like is added as a stabilizer can also be used.

FIG. 2 shows an enlarged view of a part of the first combustion pipe 16 (in the vicinity of the oxygen concentration meter 160 shown by the broken line in FIG. 1). A first porous platinum electrode 161 is attached to the inner wall surface inside the first combustion tube 16 on the tip end side of the position where the sample port 131 is inserted. A second porous platinum electrode 162 is also attached to the outer wall surface on the opposite side of the wall surface. These platinum electrodes can be formed, for example, by applying platinum paste to the inner surface and the outer surface of the combustion tube and sintering them. The 1st porous platinum electrode 161 and the 2nd porous platinum electrode 162 are connected to the voltmeter 163, and these comprise the oximeter 160. An oximeter using a stabilized zirconia as the first combustion pipe 16 is called a zirconia oximeter (for example, Non-Patent Document 1).

By partitioning the inside and outside of the first combustion tube 16 with an oxygen-conducting solid electrolyte (eg, stabilized zirconia) that constitutes the first combustion tube 16, between the first porous platinum electrode 161 and the second porous platinum electrode 162, An electromotive force having a magnitude proportional to the logarithm of the ratio of the oxygen concentration of the gas (measurement gas) flowing in the first combustion pipe 16 to the oxygen concentration (20.9%) of the atmosphere (comparative gas) outside the first combustion pipe 16 is generated. Occurs (for example, Patent Document 2). By measuring this electromotive force with the voltmeter 163, the oxygen concentration of the gas flowing in the first combustion pipe 16 can be measured.

The first pipe connecting portion 19 connects the tip end of the first combustion pipe 16 to a flow path connected to the cooler 41. The cooler 41 cools the gas released from the first combustion pipe 16. The outlet of the cooler 41 is connected to the inlet of the first separating unit 31. When passing through the first separating unit 31, gas is released from the outlet of the first separating unit 31 and water is collected in the drain pot 33. The gas released from the outlet of the first separation unit 31 is introduced into the second sample introduction chamber 24 of the inorganic carbon burning unit 20.

The inorganic carbon burning section 20 has a second sample port moving rod 23 having a sample port 231 provided at its tip. By operating the second sample port moving rod 23, the sample port 231 can be moved between the second sample introduction chamber 24 and the second combustion pipe 26. A lid 241 is provided on the upper portion of the second sample introduction chamber 24, and by removing the lid 241, the tray 22 containing the sample 11 can be set in the sample port 231. Further, as described above, the gas discharged from the first combustion pipe 16 and having passed through the cooler 41 and the first separation unit 31 is introduced into the second sample introduction chamber 24. Further, the second sample introduction chamber 24 is supplied with the acidic solution used for the reaction of the inorganic carbon from the dispenser 28.

The second combustion pipe 26 is arranged in the second combustion furnace 25. The second combustion pipe 26 is made of, for example, hard glass. The tip of the second combustion pipe 26 has a tapered shape, and the tip thereof is attached to a second pipe connection portion 29 provided outside the second combustion furnace 25. The second combustion pipe 26 is made of, for example, hard glass. In addition, the second combustion furnace 25 is heated to, for example, 200° C. during use.

The gas released from the second combustion pipe 26 passes through the second separation section 32 and is introduced into the detector 50. When passing through the second separation section 32, the water contained in the gas is removed and collected in the drain pot 33. As the detector 50, a detector that can measure the amount of carbon dioxide contained in the introduced gas is used. As the detector 50, for example, a spectrometer can be used. One of such spectrometers is a non-dispersive infrared (NDIR) spectrometer.

Next, the flow of measurement using the combustion type carbon analyzer 1 of the present embodiment will be described.

1. Measurement of Total Carbon First, the first sample port moving rod 13 is pulled out and the sample port 131 is positioned in the first sample introduction chamber 14. Next, the lid 141 of the first sample introduction chamber 14 is opened, and the tray 12 containing the sample 11 is placed on the sample port 131. Then, the lid 141 of the first sample introduction chamber is closed.

When the user gives an instruction to start the measurement from an input unit (not shown) included in the control unit 100, the measurement control unit 102 pushes the first sample port moving rod 13 to insert the sample port 131 into the first combustion pipe 16. Arrange at a predetermined position (sample introduction step). Then, a predetermined amount of oxygen gas is supplied from the oxygen cylinder 18 into the first combustion pipe 16 via the first sample introduction chamber 14 (oxygen gas supply step). This predetermined amount is, for example, 500 ml/min. This oxygen gas serves as both a combustion gas and a carrier gas. Further, the first combustion furnace 15 is operated to heat the inside of the first combustion tube 16 where the sample 11 is introduced to a predetermined temperature. The predetermined temperature is, for example, 900°C. At this time, the position of the oximeter 160 reaches, for example, 600 to 750°C.

Inside the first combustion pipe 16, the presence of the oxygen catalyst 17 arranged in advance (catalyst arranging step) and the supply of oxygen gas cause the carbon component contained in the sample 11 to burn and generate carbon dioxide. The carbon dioxide generated in the first combustion pipe 16 rides on the flow of oxygen gas and is introduced from the tip of the first combustion pipe 16 into the cooler 41 via the first pipe connecting portion 19. Then, after the water is removed by the first separation unit 31, the water is introduced into the detector 50 through the second sample introduction chamber 24, the second combustion pipe 26, the second pipe connection unit 29, and the second separation unit 32 in order. To be done.

The detector 50 measures the amount of carbon dioxide based on the light absorption. After the combustion of the sample 11 is started, the measurement is terminated when the carbon dioxide is no longer detected, and the total carbon amount in the sample 11 is calculated based on the integrated value of the measured carbon dioxide amounts.

The measurement control unit 102 reads the output signal from the voltmeter 163 of the oximeter 160 at a predetermined fixed time interval in parallel with the series of operations described above, and collates it with the conversion table stored in the storage unit 101. To do. This time interval is, for example, every 5 seconds. Thereby, the oxygen concentration in the first combustion pipe 16 is obtained and displayed on the display unit (not shown) (measurement step). Although the conversion table stored in the storage unit 101 is used here to obtain the oxygen concentration, the oxygen concentration may be obtained by another method such as using a mathematical formula for obtaining the oxygen concentration from the value of the output signal of the voltmeter 163. You may

The measurement control unit 102 also displays a message prompting the user for confirmation on the display unit when the obtained oxygen concentration is less than or equal to a predetermined value. The predetermined value can be 10.0%, 5.0%, 1.0%, for example.

In this embodiment, pure oxygen gas is supplied to the first combustion pipe 16. The decrease of the concentration to the above value suggests that the amount of oxygen gas supplied to the first combustion pipe 16 is insufficient with respect to the amount required for combustion of the sample 11. Therefore, there is a possibility that carbon is not completely burned when the sample 11 burns and a part of carbon is released as carbon monoxide. In the combustion type carbon analyzer 1 of the present embodiment, it is confirmed whether the amount of oxygen supplied to the first combustion pipe 16 is sufficient for burning the sample based on the measured value of the oxygen concentration by the oxygen concentration meter 160. can do. That is, it can be confirmed that the sample 11 is completely combusted and the correct total carbon amount is measured when the measured value of the oxygen concentration by the oximeter 160 is equal to or more than the predetermined value.

When a message prompting confirmation is displayed on the display unit, the user reduces the amount of sample to reduce the amount of oxygen required for combustion, and/or increases the flow rate of oxygen to supply oxygen. To increase. As a result, the sample 11 can be completely burned and the total carbon content can be accurately measured. Further, by supplying a sufficient amount of oxygen for burning the sample 11, the sample 11 can be efficiently burned and the total carbon amount can be efficiently measured.

2. Inorganic carbon content measurement If it is necessary to determine the inorganic carbon content or organic carbon content in the sample, measure the inorganic carbon content in addition to the total carbon content.

First, the second sample port moving rod 23 is pulled out to position the sample port 231 in the second sample introduction chamber 24. Next, the lid 241 of the second sample introduction chamber is opened, and the tray 22 containing the sample 11 is placed on the sample port 231. Then, the lid 241 of the second sample introduction chamber is closed.

When the user gives an instruction to start measurement from an input unit (not shown) included in the control unit 100, the measurement control unit 102 causes the sample in the tray 22 placed on the sample port 231 to be transferred to the sample from the dispenser 28. A fixed amount of acidic solution is added dropwise. For example, phosphoric acid is used for this acidic solution.

Then, the measurement control unit 102 pushes in the second sample port moving rod 23 to arrange the sample port 231 at a predetermined position in the second combustion pipe 26. Then, a predetermined amount of oxygen gas is supplied from the oxygen cylinder 18. This predetermined amount is, for example, 500 ml/min. The oxygen gas supplied from the oxygen cylinder 18 sequentially passes through the first sample introduction chamber 14, the first combustion pipe 16, the cooler 41, the first separation unit 31, and the second sample introduction chamber 24, and then the second combustion pipe. 26. This oxygen gas serves as both a combustion gas and a carrier gas. Further, the second combustion furnace 25 is operated to heat the inside of the second combustion pipe 26 where the sample 11 is introduced to a predetermined temperature. This predetermined temperature is, for example, 200°C.

In the second combustion pipe 26, the inorganic carbon contained in the sample 11 is burned and carbon dioxide is generated by the oxidation with the acidic solution and the supply of the oxygen gas. The carbon dioxide generated in the second combustion pipe 26 rides on the flow of oxygen gas, is introduced from the tip of the second combustion pipe 26 into the second separation unit 32 via the second pipe connection unit 29, and moisture Are removed and then introduced into the detector 50.

The detector 50 measures the amount of carbon dioxide based on the light absorption. After the combustion of the sample 11 is started, the measurement is terminated when the carbon dioxide is no longer detected, and the inorganic carbon amount in the sample 11 is obtained based on the integrated value of the measured carbon dioxide amounts. Further, the organic carbon amount is obtained by subtracting the inorganic carbon amount from the total carbon amount.

The above embodiment is an example, and can be appropriately modified in accordance with the spirit of the present invention. In the combustion-type carbon analyzer 1 of the present embodiment, the total carbon combustion unit 10 and the inorganic carbon combustion unit 20 are directly arranged, but they may be arranged in parallel. Further, in the above-mentioned embodiment, both the total carbon amount and the inorganic carbon amount contained in the sample 11 can be measured, but the configuration in which only the total carbon amount can be measured (the inorganic carbon combustion unit 20 is not provided. Configuration).

Although the oxygen concentration meter 160 is arranged in the first combustion pipe 16 in the above embodiment, it may be arranged in the middle of the flow path from the outlet of the first combustion pipe 16 to the inlet of the cooler 41. The oxygen concentration meter 160 only needs to obtain the oxygen concentration after the oxygen is consumed for the combustion of the sample 11, and may be on the downstream side (the detector 50 side) of the sample introduction position in the first combustion pipe 16. For example, it can be installed in various places. Further, when it is arranged outside the first combustion pipe 16, another type of oxygen concentration meter such as a limiting current type oxygen sensor (for example, Patent Document 3) may be used.

Further, in the above embodiment, pure oxygen is supplied, but it is also possible to adopt a structure in which the atmosphere and pure oxygen are selectively supplied. In that case, first, the atmosphere may be supplied to measure the total carbon amount, and the pure oxygen may be supplied only when the oxygen amount is insufficient.

Although various embodiments of the present invention have been described in detail with reference to the drawings, finally, various aspects of the present invention will be described. The reference numerals given below are for easy understanding, and do not limit the configuration of the present invention.

The combustion type carbon analyzer (1) of the first aspect of the present invention is
A combustion chamber (16) into which the sample (11) is introduced,
An oxygen gas supply unit (18) for supplying oxygen gas into the combustion chamber (16),
A heating unit (15) for heating the inside of the combustion chamber (16);
A measuring unit (50) for measuring the amount of carbon dioxide contained in the gas released from the combustion chamber (16);
An oxygen concentration measuring section (160) provided in a gas flow path from the sample introduction position in the combustion chamber (16) to the measuring section (50).

The carbon analysis method according to the sixth aspect of the present invention is
A sample introducing step of introducing the sample (11) into a predetermined position in the combustion chamber (15),
An oxygen gas supply step of supplying oxygen gas into the combustion chamber (15),
Measurement of measuring the amount of carbon dioxide contained in the gas released from the combustion chamber (15) while heating the combustion chamber (15) and measuring the concentration of oxygen gas after passing through the predetermined position. And steps.

In the combustion-type carbon analyzer of the first aspect and the carbon-analysis method of the sixth aspect, the sample is burned by heating while supplying oxygen gas to the combustion chamber, and a gas flow path from the sample introduction position to the measurement part is obtained. Measure the oxygen concentration with. In the combustion type carbon analyzer according to the present invention, it can be confirmed based on the measured value of the oxygen concentration whether the amount of oxygen supplied to the combustion chamber is sufficient for burning the sample. When the amount of oxygen is insufficient, the total amount of carbon contained in the sample can be measured accurately and efficiently by increasing the supply amount of oxygen gas and completely burning the sample. ..

The combustion type carbon analyzer (1) of the second aspect of the present invention is the same as the combustion type carbon analyzer (1) of the first aspect, further comprising:
Oxidation catalyst (17) arranged in the combustion chamber (16)
Equipped with
The oxygen concentration measurement unit (160) is provided closer to the measurement unit (50) than the oxidation catalyst (17).

The carbon analysis method of the seventh aspect of the present invention is the same as the carbon analysis method of the sixth aspect, further comprising:
Before the sample introduction step, a catalyst placement step of placing an oxidation catalyst in the combustion chamber (15),
In the measuring step, the concentration of oxygen gas after passing through the oxidation catalyst (17) is measured.

Since the combustion-type carbon analyzer of the second aspect and the carbon analysis method of the seventh aspect use an oxidation catalyst, the sample can be completely burned more reliably and efficiently.

A combustion-type carbon analyzer (1) according to a third aspect of the present invention is the same as the combustion-type carbon analyzer (1) according to the fourth or fifth aspect, wherein
The oxygen concentration measuring unit (160) is provided inside the combustion chamber (16).

The carbon analysis method according to the eighth aspect of the present invention is the same as the carbon analysis method according to the sixth or seventh aspect,
In the measuring step, the concentration of oxygen gas is measured in the combustion chamber (15).

In the combustion-type carbon analyzer of the third aspect and the carbon analysis method of the eighth aspect, since the oxygen concentration immediately after oxygen is used for burning the sample is measured, whether or not the supply amount of oxygen gas is sufficient is determined. You can check more accurately.

A combustion-type carbon analyzer (1) according to a fourth aspect of the present invention is the combustion-type carbon analyzer (1) according to any one of the first to third aspects, further comprising:
A first opening detachably attached to the combustion chamber (15) for inserting and removing the tray (12) containing the sample (11) and carbon dioxide generated by the combustion of the sample (11) are generated. A combustion tube (16) having a second opening to be discharged;
Tray operating part (13) for loading/unloading the tray (12) into/out of the combustion pipe (16) through the first opening.
Equipped with.

Since the combustion-type carbon analyzer of the fourth aspect uses the combustion tube detachably attached to the combustion chamber, it is easy to clean or replace the combustion tube when dirt adheres to the inside of the combustion tube due to combustion of the sample. It can be carried out. In addition, since the tray containing the sample can be taken in and out of the combustion tube by the tray operation unit, the sample can be easily set.

Moreover, the combustion-type carbon analyzer (1) of the fifth aspect of the present invention is the same as the combustion-type carbon analyzer (1) of the fourth aspect,
The oxygen concentration measuring unit (160) is a zirconia oximeter (160), and the zirconia oximeter is provided on the wall surface of the combustion pipe.

In the combustion-type carbon analyzer of the fifth aspect, since the zirconia-type oxygen concentration meter having sufficient heat resistance is used for the oxygen concentration measurement unit, the oxygen concentration inside the combustion chamber can be accurately measured.

DESCRIPTION OF SYMBOLS 1... Combustion-type carbon analyzer 10... Total carbon combustion part 11... Sample 12... Tray 13... 1st sample port moving rod 131... Sample port 14... 1st sample introduction chamber 141... Lid 15... 1st combustion furnace 16... No. 1 Combustion tube 160... Oxygen concentration meter 161... 1st porous platinum electrode 162... 2nd porous platinum electrode 163... Voltmeter 17... Oxygen catalyst 18... Oxygen cylinder 181... Flow rate adjustment part 20... Inorganic carbon combustion part 22... Tray 23... Second sample port moving rod 231... Sample port 24... Second sample introducing chamber 241... Lid 26... Second combustion tube 27... Second combustion furnace 28... Dispenser 31... First separation part 32... Second Separation unit 33... Drain pot 41... Cooler 50... Detector 100... Control unit 101... Storage unit 102... Measurement control unit

Claims (8)

A combustion chamber into which the sample is introduced,
An oxygen gas supply unit for supplying oxygen gas into the combustion chamber,
A heating unit for heating the combustion chamber,
A carbon dioxide measuring unit for measuring the amount of carbon dioxide contained in the gas released from the combustion chamber,
A combustion-type carbon analysis device, comprising: an oxygen concentration measurement unit provided in a gas flow path from the sample introduction position in the combustion chamber to the measurement unit. further,
An oxidation catalyst disposed in the combustion chamber,
The combustion type carbon analyzer according to claim 1, wherein the oxygen concentration measuring unit is provided closer to the measuring unit than the oxidation catalyst. The combustion-type carbon analyzer according to claim 1, wherein the oxygen concentration measurement unit is provided inside the combustion chamber. further,
A combustion tube that is detachably attached to the combustion chamber and has a first opening for loading and unloading a tray containing the sample, and a second opening for releasing carbon dioxide generated by combustion of the sample,
The combustion-type carbon analyzer according to claim 1, further comprising a tray operation unit that moves the tray in and out of the combustion pipe through the first opening. The combustion-type carbon analyzer according to claim 4, wherein the oxygen concentration measuring unit is a zirconia-type oxygen concentration meter, and the zirconia-type oxygen concentration meter is provided on a wall surface of the combustion pipe. A sample introduction step of introducing a sample into a predetermined position in the combustion chamber,
An oxygen gas supply step of supplying oxygen gas into the combustion chamber,
Measuring the amount of carbon dioxide contained in the gas released from the combustion chamber while heating the combustion chamber, and measuring the concentration of oxygen gas after passing through the predetermined position. Method. further,
Before the sample introduction step, a catalyst placement step of placing an oxidation catalyst in the combustion chamber,
The carbon analysis method according to claim 6, wherein, in the measuring step, the concentration of oxygen gas after passing through the oxidation catalyst is measured. The carbon analysis method according to claim 6 or 7, wherein the concentration of oxygen gas is measured in the combustion chamber in the measurement step.

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