JP2017194303A - Total organic carbon measurement device and total organic carbon measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a total organic carbon measurement device and a total organic carbon measurement method with which it is possible to realize measurement with high accuracy by a simple configuration.SOLUTION: A preprocessing control unit 112 stores a sample and an acid solution in the barrel of a syringe 3, and closes up the opening of the barrel. The preprocessing control unit 112 retracts a plunger from inside the barrel of the syringe 3 and thereby reduces the pressure in the barrel, causing the sample and the acid solution to react and generating carbon dioxide. A reaction control unit 111 causes the plunger to enter the barrel to introduce the sample in the barrel into each of a TC combustion unit 4 and an IC reaction unit. Thus, a preprocess for reacting the sample and the acid solution in the syringe 3 and generating carbon dioxide is carried out in a total organic carbon measurement device 1. Furthermore, the preprocess is carried out in the syringe 3 without bubbling the sample. Therefore, it is possible to realize measurement with high accuracy by a simple configuration.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a total organic carbon measuring device for measuring total organic carbon contained in a sample, and a total organic carbon measuring method using the total organic carbon measuring device.

  Conventionally, total organic carbon measuring devices for measuring total organic carbon contained in various samples in addition to environmental water such as river water, lake water, marine water, rain water, and groundwater have been used.

  As a total organic carbon measurement device, carbon dioxide is generated from inorganic carbon contained in the sample, carbon dioxide is generated from all carbon contained in the sample, and all the carbon atoms contained in the sample are determined based on the generated carbon dioxide. An apparatus for measuring airframe carbon is known (for example, see Patent Document 1 below).

  The all-organic carbon measuring device described in Patent Literature 1 includes a removal processing unit, a carbon combustion unit, and a detection unit (measurement unit). In this total organic carbon measuring device, a sample is first sent to a removal processing unit. And in a removal process part, an acid is added to a sample and it is bubbled, A carbon dioxide will generate | occur | produce from the inorganic carbon contained in a sample, and inorganic carbon will be removed. The sample after the inorganic carbon is removed is sent to the carbon combustion section. And in a carbon combustion part, a sample will be heated and a carbon dioxide will generate | occur | produce. The detection unit detects carbon dioxide generated in the carbon combustion unit. Based on the amount of carbon dioxide detected by the detector, the amount of total organic carbon contained in the sample is calculated.

Japanese Patent No. 2671773

  In the conventional total organic carbon measuring apparatus as described above, the sample and the acid are bubbled in the removal processing section as the pretreatment. Therefore, for example, when a surfactant is included in the sample, bubbles are generated by bubbling. When bubbles are generated from the sample, a part of the sample may overflow from the container due to the bubbles, and in this case, the total organic carbon cannot be calculated accurately.

  Therefore, it is considered to perform pretreatment on the sample without bubbling. Specifically, it is considered that carbon dioxide is generated from inorganic carbon contained in the sample by separately providing a pretreatment configuration (apparatus) and placing the acidified sample under reduced pressure. For example, if an acidic sample is passed through a porous material such as a hollow system (a fine tube made of a material that does not allow liquid to pass through gas) and the outside of the hollow system is decompressed, the inorganic substance contained in the sample Carbon dioxide can be generated from carbon for pretreatment. However, in this case, in order to discharge carbon dioxide out of the system, it is necessary to suck air from the outside, and it is also necessary to separately provide components for removing impurities contained in the sucked air. Also, a unit using a porous material such as a hollow system is required, which complicates the configuration of the entire apparatus and increases the manufacturing cost.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an all-organic carbon measuring apparatus and an all-organic carbon measuring method capable of realizing measurement with high accuracy with a simple configuration.

(1) The total organic carbon measuring device according to the present invention measures total organic carbon contained in a sample. The all-organic carbon measuring device includes a TC combustion unit, a syringe, and a pretreatment control unit. The TC combustion unit generates carbon dioxide by burning all the carbon contained in the sample. The syringe has a hollow barrel and a plunger that can be moved back and forth with respect to the inside of the barrel. By retracting the plunger from the inside of the barrel, the syringe enters the barrel from the opening formed in the barrel. By sucking a sample and causing the plunger to enter the barrel, the sample in the barrel is introduced into the TC combustion portion from the opening. The pretreatment control unit forms a space in the barrel by retracting the plunger from the barrel while the sample and the acid solution are stored in the barrel and the opening is closed. The carbon dioxide generated by the reaction of the sample with the acid solution is extracted into the space.

  According to such a configuration, the pretreatment control unit depressurizes the inside of the barrel by retracting the plunger from the barrel while the sample and the acid solution are stored in the barrel and the opening is closed. Then, the sample is reacted with the acid solution. Within the barrel, carbon dioxide is extracted into the space formed by the withdrawal of the plunger. Further, the sample in the barrel is introduced into the TC combustion section from the opening when the plunger enters the barrel. In the TC combustion section, carbon dioxide is generated by burning all the carbon contained in the sample.

As described above, in the total organic carbon measurement device, the pretreatment for sucking the sample and reacting the sample with the acid solution to generate carbon dioxide is performed in the syringe for introducing the sucked sample into the TC combustion unit. Is called.
Therefore, it is possible to pre-process the sample using the existing configuration in the total organic carbon measuring device.
As a result, it is possible to pre-process the sample while simply configuring the total organic carbon measuring device.

Further, the pretreatment for the sample is performed by retracting the plunger from the barrel while the sample and the acid solution are stored in the barrel and the opening is closed.
Therefore, pretreatment can be performed on the sample without bubbling.
As a result, bubbles can be prevented from being generated from the sample, and the sample can be prevented from overflowing from the container.
That is, according to the all-organic carbon measuring apparatus according to the present invention, it is possible to realize measurement with high accuracy with a simple configuration.

(2) In addition, the pretreatment control unit causes the plunger to enter the barrel with the opening being opened to the atmosphere after extracting the carbon dioxide into the space. Of carbon dioxide may be released into the atmosphere from the opening.

  According to such a configuration, the carbon dioxide extracted in the barrel can be released into the atmosphere by a simple operation (control) in which the plunger enters the barrel.

(3) The total organic carbon measurement device may further include an IC reaction unit, a detection unit, and a total organic carbon calculation unit. The IC reaction unit generates carbon dioxide by reacting inorganic carbon contained in the sample with an acid solution. The detection unit detects carbon dioxide generated by introducing a sample and an acid solution from which carbon dioxide has been extracted in the barrel into the TC combustion unit and the IC reaction unit, respectively. The total organic carbon calculation unit calculates the total organic carbon contained in the sample based on the detection result in the detection unit.

  In general, the total organic carbon measurement apparatus can measure inorganic carbon and total carbon contained in a sample, and can measure total organic carbon contained in the sample based on these results. This is based on the relational expression of TOC (total organic carbon) = TC (total carbon) -IC (inorganic carbon).

  In the case where total organic carbon is measured based on such a measurement method, an error may occur between the measured value of inorganic carbon and the measured value of total carbon. And when the measured value of inorganic carbon and the measured value of all carbon are both large, the ratio of the error to the whole becomes large, and the error caused by the measured value of all organic carbon becomes large. End up.

  According to the configuration as described above, in the total organic carbon measurement device, the sample and the acid solution are stored in the barrel, and the plunger is retracted from the barrel with the opening closed, When carbon dioxide is extracted in the barrel, a large amount of inorganic carbon contained in the sample is removed. In the IC reaction part, carbon dioxide is generated by the reaction of the inorganic carbon slightly remaining in the sample with the acid solution. In the TC combustion section, carbon dioxide is generated by burning all the carbon contained in the sample. The detection unit detects these carbon dioxides. The total organic carbon calculation unit calculates the total organic carbon contained in the sample based on the detection result of the detection unit.

Therefore, even if an error occurs at a fixed ratio for each of the measured value of inorganic carbon and the measured value of all carbon, the ratio of the error to the whole can be reduced.
As a result, the ratio of errors included in the measured value of total organic carbon can be reduced.

(4) The method for measuring total organic carbon according to the present invention includes a TC combustion section that generates carbon dioxide by burning all carbon contained in a sample, a hollow barrel, and a forward and backward movement with respect to the inside of the barrel. A syringe having a possible plunger and a detection unit for detecting carbon dioxide generated in the TC combustion unit, and is used to measure total organic carbon contained in a sample based on a detection result in the detection unit. Airframe carbon measuring device is used. The total organic carbon measurement method includes a pretreatment step, a sample introduction step, and a total organic carbon calculation step. In the pretreatment step, a sample and an acid solution are stored in the barrel, and a space is formed in the barrel by retracting the plunger from the barrel with the opening closed. Carbon dioxide generated by the reaction of the sample with the acid solution is extracted into the space. In the sample introduction step, the sample and the acid solution from which carbon dioxide has been extracted in the pretreatment step are introduced from the barrel into the TC combustion unit. In the total organic carbon calculation step, the total organic carbon contained in the sample is calculated based on the detection result of the carbon dioxide generated in the TC combustion unit in the detection unit.

(5) In the pretreatment step, after the carbon dioxide is extracted into the space, the plunger is inserted into the barrel with the opening being opened to the atmosphere. Carbon dioxide may be released into the atmosphere from the opening.

(6) The total organic carbon measuring device may further include an IC reaction unit. The IC reaction unit generates carbon dioxide by reacting inorganic carbon contained in the sample with an acid solution. In the sample introduction step, carbon dioxide is generated by introducing the sample after the carbon dioxide is extracted in the pretreatment step and the acid solution from the barrel into the TC combustion unit and the IC reaction unit, respectively. Also good. In the total organic carbon calculation step, the total organic carbon contained in the sample may be calculated based on a detection result of the carbon dioxide generated in the TC combustion unit and the IC reaction unit in the detection unit.

  According to the present invention, in the syringe for sucking the sample and introducing the sucked sample into the TC combustion unit, the pretreatment for reacting the sample with the acid solution to generate carbon dioxide is performed. Further, the pretreatment for the sample is performed by retracting the plunger from the barrel while the sample and the acid solution are stored in the barrel and the opening is closed. Therefore, high-accuracy measurement can be realized with a simple configuration.

It is the schematic which showed the all-organic carbon measuring apparatus which concerns on one Embodiment of this invention. It is the block diagram which showed the specific structure of the control part of the all-organic carbon measuring apparatus of FIG. 1, and its peripheral member. It is the schematic for demonstrating the operation | movement in the syringe of the all-organism carbon measuring apparatus of FIG. 1, Comprising: The state where the acid solution is attracted | sucked in the barrel is shown. It is the schematic for demonstrating the operation | movement in the syringe of the all-organism carbon measuring apparatus of FIG. 1, Comprising: The plunger is arrange | positioned in a barrel and the state by which a barrel is sealed is shown. It is the schematic for demonstrating the operation | movement in the syringe of the all-organism carbon measuring apparatus of FIG. 1, Comprising: The barrel is sealed and the state which the plunger retracts | saves is shown. It is the schematic for demonstrating the operation | movement in the syringe of the all-organism carbon measuring apparatus of FIG. 1, Comprising: The state which discharge | releases the carbon dioxide in a barrel outside is shown. It is the schematic for demonstrating the operation | movement in the syringe of the all-organism carbon measuring apparatus of FIG. 1, Comprising: The state which sends out the sample in a barrel is shown. It is the flowchart which showed an example of the process by a control part.

1. Overall Configuration of Total Organic Carbon Measuring Device FIG. 1 is a schematic diagram showing a total organic carbon measuring device 1 according to an embodiment of the present invention.
The total organic carbon measuring device 1 is based on inorganic carbon (IC: Inorganic Carbon) and total carbon (TC: Total Carbon) contained in a sample, and is based on total organic carbon (TOC) contained in the sample. , And includes a supply unit 2, a syringe 3, a TC combustion unit 4, an IC reaction unit 5, a dehumidifier 6, and a detection unit 7.

The supply unit 2 is for supplying a sample, a solution, or the like (additive) used in the total organic carbon measuring device 1, and includes a sample supply unit 21, an acid solution supply unit 22, and a pure water supply unit 23. And.
The sample supply unit 21 stores a liquid sample to be measured.
The acid solution supply unit 22 stores an acid solution used for measurement. The acid solution stored is, for example, HCl.

  The pure water supply unit 23 stores pure water. The pure water is used as an internal liquid (described later) of the IC reaction unit 5 and cleaning water for each member. However, the internal liquid is not limited to pure water but may be an electrolyte solution or the like.

The syringe 3 is for selectively collecting and sending each additive in the supply unit 2. The syringe 3 includes a sample suction channel 10 continuous in the sample supply unit 21, an acid solution suction channel 11 continuous in the acid solution supply unit 22, a wash water suction channel 12 continuous in the pure water supply unit 23, Any of the first transfer flow path 13 connected to the TC combustion unit 4, the second transfer flow path 14 connected to the IC reaction unit 5, the first drain flow path 15, and the gas discharge flow path 20 (described later). Can be selectively connected. The detailed configuration of the syringe 3 will be described later.
The TC combustion unit 4 is for generating carbon dioxide by burning all the carbon contained in the sample, and includes an electric furnace 41 and a combustion tube 42.
The electric furnace 41 is for heating (combusting) the sample to be measured, and is formed in a hollow shape.

  The combustion tube 42 is disposed in the electric furnace 41. The combustion tube 42 is made of, for example, hard glass (quartz glass). The combustion pipe 42 is filled with an oxidation catalyst (not shown). When the sample is injected into the combustion tube 42, the organic matter contained in the sample is oxidized by the action of the oxidation catalyst to generate carbon dioxide corresponding to the amount of the organic matter (total carbon) contained in the sample. The combustion pipe 42 is connected to the first transfer flow path 13 and the first gas supply pipe 16 at one end thereof, and the second gas supply pipe 17 is connected to the other end thereof. Carrier gas flows from the first gas supply pipe 16 into the combustion pipe 42.

  The IC reaction unit 5 is for generating carbon dioxide by reacting inorganic carbon contained in a sample with an acid solution. The IC reaction part 5 is formed in a long hollow shape, and is configured to store liquid therein. The second transfer flow path 14 is connected to one end (upper end) of the IC reaction unit 5, and the second gas supply pipe 17 is connected to the other end (lower end) of the IC reaction unit 5. Has been. Further, an internal liquid supply channel 18 and a second drain channel 19 are connected to the IC reaction unit 5. The IC reaction unit 5 is provided between the TC combustion unit 4 and a detection unit 7 described later.

  One end of the internal liquid supply channel 18 is continuous in the pure water supply unit 23, and the other end is connected to the IC reaction unit 5. A pump 100 is interposed in the internal liquid supply channel 18.

  The second drain channel 19 is connected to the central part of the IC reaction unit 5. The liquid (internal liquid) in the IC reaction unit 5 is discharged to the outside from the second drain channel 19 when a certain amount or more is reached. A valve 101 is interposed in the second drain channel 19. When the valve 101 is opened, the second drain channel 19 discharges the internal liquid that has become a certain amount or more in the IC reaction unit 5 to the outside, and when the valve 101 is closed, the IC reaction unit 5 The gas passing through the inside is guided to the discharge pipe 102 side.

  The dehumidifier 6 is for removing moisture contained in the gas discharged from the IC reaction unit 5, and is disposed in the middle of a discharge pipe 102 that connects the IC reaction unit 5 and a detection unit 7 described later. Has been placed.

  The detection unit 7 is for detecting carbon dioxide contained in the gas discharged through the discharge pipe 102. The detection part 7 is comprised by the infrared carbon dioxide detector, for example.

  In the total organic carbon measuring device 1, the carrier gas is constantly supplied to the first gas supply pipe 16. Therefore, in the total organic carbon measurement device 1, the first gas supply pipe 16, the TC combustion section 4, the second gas supply pipe 17, the IC reaction section 5, and the discharge pipe 102 are sequentially passed toward the detection section 7. A carrier gas flow is formed.

  In the total organic carbon measuring device 1, first, pure water is supplied into the IC reaction unit 5 from the pure water supply unit 23 through the internal liquid supply channel 18 by the operation of the pump 100, The solution is collected (sucked) into the syringe 3 from the acid solution supply unit 22 via the acid solution suction channel 11. The collected acid solution is added (dropped) from the syringe 3 to the IC reaction unit 5 through the second transfer channel 14. Thereby, a certain amount of acidic solution (pure water and acid solution) is stored in the IC reaction part 5 as an internal solution.

  In the following description, the inside of the syringe 3 is appropriately cleaned by sucking pure water in the pure water supply unit 23, and the liquid that is no longer necessary in the syringe 3 is appropriately discharged from the first drain channel 15. Discharged.

  Then, the sample is sucked into the syringe 3 from the sample supply unit 21 via the sample suction channel 10. The sample is added (dropped) from the syringe 3 to the IC reaction unit 5 through the second transfer channel 14.

  The internal liquid in the IC reaction unit 5 is bubbled by the carrier gas supplied from the second gas supply pipe 17. Thereby, the inorganic carbon contained in the sample reacts with the acid solution (acid solution) to generate carbon dioxide. The generated carbon dioxide is dehydrated by the dehumidifier 6 in the process of passing through the discharge pipe 102, and then flows into the detection unit 7. The detection unit 7 detects the amount of carbon dioxide exhausted from the exhaust pipe 102. Then, based on the amount of carbon dioxide detected by the detection unit 7, inorganic carbon (IC concentration) contained in the sample is measured.

  In addition, the sample is sucked into the syringe 3 from the sample supply unit 21 via the sample suction channel 10 while the internal liquid in the IC reaction unit 5 is in an acidic state. The sucked sample is introduced from the syringe 3 into the combustion tube 42 of the TC combustion unit 4 through the first transfer flow path 13. When the combustion tube 42 is heated by the electric furnace 41, carbon dioxide corresponding to the amount of organic matter (total carbon) contained in the sample is generated in the combustion tube 42. Carbon dioxide generated in the combustion pipe 42 passes through the second gas supply pipe 17, the IC reaction section 5, and the discharge pipe 102 and flows into the detection section 7. The detection unit 7 detects the amount of carbon dioxide exhausted from the exhaust pipe 102. And based on the quantity of the carbon dioxide which the detection part 7 detected, the total carbon (TC density | concentration) contained in a sample is measured.

  And in the total organic carbon measuring device 1, based on the relational expression of TOC = TC-IC and the measured inorganic carbon (IC concentration) and total carbon (TC concentration), the total organic carbon (TOC Concentration) is measured.

  In such a measuring method, an error may occur in each of the measured value of inorganic carbon and the measured value of all carbon. When both the measured value of inorganic carbon and the measured value of all carbon are large, the ratio of error to the whole becomes large, and the error generated in the measured value of all organic carbon becomes large. Therefore, in the present embodiment, pretreatment is performed on the sample using the following configuration and method.

2. FIG. 2 is a block diagram showing a specific configuration of the control unit 110 of the total organic carbon measuring device 1 and its peripheral members.

  The total organic carbon measuring device 1 includes an operation unit 105, a display unit 106, a carrier gas delivery unit 107, and a control unit 110 in addition to the syringe 3, the TC combustion unit 4, the detection unit 7, and the pump 100 described above. .

The operation unit 105 is configured by, for example, a keyboard and a mouse. The user can input various information such as measurement conditions to the control unit 110 by operating the operation unit 105.
The display unit 106 is configured by, for example, a liquid crystal display. Various information such as measurement results are displayed on the display unit 106 under the control of the control unit 110.

  The carrier gas delivery unit 107 supplies a carrier gas to the first gas supply pipe 16 and the third gas supply pipe 30 (described later). The carrier gas delivery unit 107 constantly supplies a carrier gas to the first gas supply pipe 16, while supplying a carrier gas to the third gas supply pipe 30 as necessary.

For example, the control unit 110 includes a CPU (Central Processing Unit). The control unit 110 can input or output an electrical signal among the syringe 3, the TC combustion unit 4, the detection unit 7, the pump 100, the operation unit 105, the display unit 106, and the carrier gas delivery unit 107. The control unit 110 functions as a reaction control unit 111, a pretreatment control unit 112, a total organic carbon calculation processing unit 113, a display processing unit 114, and the like when the CPU executes a program.
The reaction control unit 111 performs processing for controlling operations of the syringe 3, the TC combustion unit 4, the pump 100, and the carrier gas delivery unit 107.
The preprocessing control unit 112 performs processing for controlling operations of the syringe 3 and the carrier gas delivery unit 107.
The total organic carbon calculation processing unit 113 calculates the concentrations of inorganic carbon, total carbon, and total organic carbon based on the detection signal from the detection unit 7.
The display processing unit 114 performs processing for causing the display unit 106 to display the result calculated by the total organic carbon calculation processing unit 113.

3. Detailed Configuration of Syringe FIG. 3A is a schematic diagram for explaining the operation of the syringe 3, and shows a state where the acid solution is sucked into the barrel 31.
The syringe 3 described above includes a barrel 31, a plunger 32, and a distribution valve 33.

  The barrel 31 is formed in a long hollow shape. An opening 31 </ b> A is formed at the tip (one end) of the barrel 31. A vent hole (not shown) is formed at the other end of the barrel 31, and the carrier gas flows into the inside from the third gas supply pipe 30 through this hole. The third gas supply pipe 30 is shown only in FIG. 3A for convenience of explanation, and is not shown in FIGS. 3B to 3E described later.

  The plunger 32 is formed in a rod shape and is inserted into the barrel 31. The tip of the plunger 32 and the inner peripheral surface of the barrel 31 are in close contact. The plunger 32 slides (advances and retreats) along the axial direction of the barrel 31 when a driving force from a motor (not shown) is applied.

  The distribution valve 33 is a multi-port distribution valve having one common port 33A and eight distribution ports 33B. The distribution valve 33 selectively connects the common port 33A and any one of the distribution ports 33B by applying a driving force from a motor (not shown). The tip of the barrel 31 is connected to the common port 33 </ b> A of the distribution valve 33. Among the distribution ports 33B of the distribution valve 33, the seven distribution ports 33B include the sample suction channel 10, the acid solution suction channel 11, the washing water suction channel 12, the first transfer channel 13, and the like shown in FIG. The 2nd transfer flow path 14, the 1st drain flow path 15, and the gas discharge flow path 20 are connected. One end of the gas discharge channel 20 is open to the atmosphere. As shown in FIG. 3A, one distribution port 33B of the distribution ports 33B of the distribution valve 33 is sealed. In FIG. 3A and FIGS. 3B to 3E described later, only the acid solution suction channel 11, the second transfer channel 14, and the gas discharge channel 20 are used as members connected to the distribution port 33B for convenience of explanation. The sample suction channel 10, the washing water suction channel 12, the first transfer channel 13, and the first drain channel 15 are not shown.

  In the syringe 3, when the distribution valve 33 is operated, the common port 33A and the selected one distribution port 33B are appropriately connected. Then, as the plunger 32 moves back and forth in the barrel 31, a sample or the like is sucked from the supply unit 2 (see FIG. 1), and pretreatment is performed on the sucked sample.

4). Control Operation by Control Unit FIGS. 3B to 3E are schematic diagrams for explaining the operation in the syringe 3, respectively. Specifically, FIG. 3B shows a state where the plunger 32 is disposed in the barrel 31 and the barrel 31 is sealed. FIG. 3C shows a state where the barrel 31 is sealed and the plunger 32 is retracted. FIG. 3D shows a state in which carbon dioxide in the barrel 31 is discharged to the outside. FIG. 3E shows a state in which the sample in the barrel 31 is delivered. FIG. 4 is a flowchart illustrating an example of processing by the control unit 110.
Hereinafter, the control operation by the control unit 110 will be described with reference to FIGS. 3A to 3E and FIG. 4.

As described above, when measuring the total organic carbon contained in the sample, first, the user operates the operation unit 105 to input measurement conditions and the like, and then starts measurement.
In the total organic carbon measuring device 1, as described above, a certain amount of acidic solution (pure water and acid solution) is stored in the IC reaction unit 5 as an internal solution. At this time, the plunger 32 is located in the deepest part in the barrel 31 (the uppermost part in FIG. 3A).

Next, the pretreatment control unit 112 (see FIG. 2) operates the distribution valve 33 of the syringe 3 to connect the common port 33A and the distribution port 33B continuous to the sample suction channel 10 (see FIG. 1). Connect (not shown). Then, the reaction control unit 111 operates to retract the plunger 32 from the barrel 31, and sucks the sample from the sample supply unit 21 through the sample suction channel 10 into the barrel 31. Further, as shown in FIG. 3A, the reaction control unit 111 operates the distribution valve 33 to connect the common port 33 </ b> A and the distribution port 33 </ b> B continuous to the acid solution suction channel 11. Then, the reaction control unit 111 operates so as to retract the plunger 32 from the barrel 31, and the acid solution is supplied from the acid solution supply unit 22 through the acid solution suction channel 11 into the barrel 31 from the opening 31 </ b> A. Suction. Thereby, the sample and the acid solution are stored in the barrel 31.
In this example, 1 ml of the sample is sucked into the barrel 31 and 50 μl of HCl (1N) is sucked.

  Thereafter, the pretreatment control unit 112 operates the distribution valve 33 to connect the common port 33A and the distribution port 33B continuous to the gas discharge flow path 20. Then, the reaction control unit 111 operates to retract the plunger 32 from the barrel 31 (not shown).

Then, the pretreatment control unit 112 introduces the carrier gas into the barrel 31 from the carrier gas delivery unit 107 via the third gas supply pipe 30 for a predetermined time. Thereby, the sample and the acid solution are mixed in the barrel 31 (step S101). The predetermined time is a short time necessary for mixing the sample and the acid solution.
In this example, carrier gas is introduced into the barrel 31 for 0.5 seconds.

Next, as shown in FIG. 3B, the pretreatment control unit 112 moves the plunger 32 into the barrel 31 until the upper surface of the liquid (sample and acid solution) in the barrel 31 reaches one end (upper end) of the barrel 31. Let it enter. Further, the preprocessing control unit 112 operates the distribution valve 33 to connect the common port 33A and the sealed distribution port 33B (step S102).
Thereby, the opening 31A of the barrel 31 is closed.

Thereafter, as shown in FIG. 3C, the pretreatment control unit 112 operates the plunger 32 to retract from the barrel 31 to form a space A in the barrel 31 (with the upper surface of the liquid in the barrel 31). The space A is formed between one end of the barrel and the inside of the barrel 31 is decompressed (step S103).
Further, the preprocessing control unit 112 maintains the state where the plunger 32 is retracted from the barrel 31 for a predetermined time.
In this example, the state in which the plunger 32 is retracted from the barrel 31 (the state shown in FIG. 3C) is maintained for 90 seconds.
Thereby, inorganic carbon contained in the sample reacts with the acid solution, carbon dioxide is extracted into the space A, and a large amount of inorganic carbon is removed.
This is due to the following formula (1).

Formula (1) has shown the presence form of the carbon dioxide in water. Specifically, equation (1) shows that when the pH of water is lowered (becomes acidic), the equilibrium moves to the left and all of the carbon dioxide is present as dissolved carbon dioxide (dissolved CO ₂ ). Yes.

That is, since the sample and the acid solution are mixed in the barrel 31, the inorganic carbon contained in the sample becomes dissolved carbon dioxide (dissolved CO ₂ ). And the inside of the barrel 31 is decompressed, and the dissolved carbon dioxide (dissolved CO ₂ ) is gradually extracted into the space A of the barrel 31 as a gas (pretreatment step).

When a predetermined time elapses with the plunger 32 retracted from the barrel 31 (YES in step S104), the preprocessing control unit 112 operates the distribution valve 33 as shown in FIG. 3D to operate the common port 33A. And the distribution port 33B continuing to the gas discharge flow path 20 are connected (step S105), and the plunger 32 is operated to enter the barrel 31. In other words, the pretreatment control unit 112 opens the barrel 31 A to the atmosphere so that the inside of the barrel 31 is at a normal pressure and operates so that the plunger 32 enters the barrel 31. At this time, the pretreatment control unit 112 moves the plunger 32 until the upper surface of the liquid (sample and acid solution) in the barrel 31 reaches one end (upper end) of the barrel 31 (until the space A shown in FIG. 3C disappears). Is entered into the barrel 31, and the carbon dioxide contained in the barrel 31 is released from the gas discharge flow path 20 into the atmosphere (step S106).
In this way, the pretreatment is performed on the sample sucked into the barrel 31.

Next, as illustrated in FIG. 3E, the reaction control unit 111 operates the distribution valve 33 to connect the common port 33 </ b> A and the distribution port 33 </ b> B continuous with the second transfer flow path 14. Then, the reaction control unit 111 operates the plunger 32 so as to enter the barrel 31, sends the sample (sample and acid solution) in the barrel 31 from the opening 31 </ b> A, and the second transfer channel 14. Is added (dropped) to the internal solution of the IC reaction unit 5 via (step S107).
In this example, 100 μl of the sample in the barrel 31 is added to the IC reaction unit 5.

  In the IC reaction section 5, inorganic carbon slightly contained in the sample reacts with the internal liquid (acidic solution) to generate carbon dioxide. The carbon dioxide is supplied to the detection unit 7 through the discharge pipe 102 by the flow of the carrier gas. Then, the amount of carbon dioxide is detected by the detection unit 7, and the inorganic carbon (IC concentration) contained in the sample is calculated by the total organic carbon calculation processing unit 113.

Although not shown, the reaction control unit 111 operates the distribution valve 33 to connect the common port 33 </ b> A and the distribution port 33 </ b> B continuous with the first transfer flow path 13. Then, the reaction control unit 111 operates to cause the plunger 32 to enter the barrel 31, sends the sample in the barrel 31 from the opening 31 </ b> A, and passes through the first transfer flow path 13 to the TC combustion unit 4. Into the combustion tube 42 (sample introduction step).
In this example, 100 μl of the sample in the barrel 31 is added to the TC combustion unit 4.
Further, in the TC combustion unit 4, the temperature inside the electric furnace 41 is adjusted to a predetermined temperature (in this example, 680 ° C.) by the reaction control unit 111.

  As a result, the combustion tube 42 is heated by the electric furnace 41, and in the combustion tube 42, all the carbon contained in the sample is burned to generate carbon dioxide. The carbon dioxide generated in the combustion tube 42 is supplied to the detection unit 7 through the second gas supply tube 17, the IC reaction unit 5, and the discharge tube 102 in order by the flow of the carrier gas. Then, the amount of carbon dioxide is detected by the detection unit 7, and the total carbon (TC concentration) contained in the sample is calculated by the total organic carbon calculation processing unit 113.

  Then, the total organic carbon calculation processing unit 113 applies the calculated values of the inorganic carbon (IC concentration) and the total carbon (TC concentration) to the relational expression of TOC = TC-IC, so that the total organic carbon (TOC concentration) is calculated (step S108; total organic carbon calculation step). The calculated total organic carbon (TOC concentration) is displayed on the display unit 106 by the display processing unit 114.

  As described above, in the total organic carbon measuring apparatus 1, a large amount of inorganic carbon contained in the sample is removed as a pretreatment for the sample in the syringe 3. Then, the total organic carbon (TOC concentration) is calculated from the relational expression TOC = TC-IC using the pretreated sample. At this time, since the sample has been pretreated, both the measured value of the inorganic carbon (IC concentration) and the measured value of the total carbon (TC concentration) become small. As a result, even if an error occurs at a constant ratio for each of the measured value of the total carbon (TC concentration) and the measured value of the inorganic carbon (IC concentration), the final calculated value (TOC concentration) The error rate is reduced.

5. Action and Effect (1) In the present embodiment, as shown in FIG. 3B, the pretreatment control unit 112 stores the sample and the acid solution in the barrel 31 and closes the opening 31A of the barrel 31. As shown in FIG. 3C, by retracting the plunger 32 from the barrel 31, the inside of the barrel 31 is decompressed, and the sample and the acid solution are reacted. Within the barrel 31, carbon dioxide is extracted into the space A formed by retracting the plunger 32. The sample in the barrel 31 is introduced into the TC combustion unit 4 from the opening 31 </ b> A when the plunger 32 enters the barrel 31. In the TC combustion unit 4, carbon dioxide is generated by burning all the carbon contained in the sample.

As described above, in the total organic carbon measuring apparatus 1, the sample is sucked, and before the carbon dioxide is generated by reacting the sample with the acid solution in the syringe 3 for introducing the sucked sample into the TC combustion unit 4. Processing is performed.
Therefore, it is possible to pre-process the sample using the existing configuration in the all-organic carbon measuring apparatus 1.
As a result, it is possible to pre-process the sample while simply configuring the total organic carbon measuring device 1.

Further, the pretreatment for the sample is performed by retracting the plunger 32 from the barrel 31 in a state where the sample and the acid solution are stored in the barrel 31 and the opening 31A is closed.
Therefore, pretreatment can be performed on the sample without bubbling.
As a result, bubbles can be prevented from being generated from the sample, and the sample can be prevented from overflowing from the container.
That is, according to the all-organic carbon measuring device 1, it is possible to realize measurement with high accuracy with a simple configuration.

(2) In the present embodiment, the pretreatment control unit 112 extracts the carbon dioxide from the sample in the barrel 31, and then enters the plunger 32 into the barrel 31 with the opening 31A open to the atmosphere. By doing so, the carbon dioxide in the barrel 31 is released into the atmosphere from the opening 31A.
Therefore, carbon dioxide extracted into the barrel 31 can be released into the atmosphere by a simple operation (control) in which the plunger 32 only enters the barrel 31.

(3) In the present embodiment, in the total organic carbon measuring device 1, the detection unit 7 includes the TC combustion unit 4 and the IC reaction unit after the sample and the acid solution after the carbon dioxide is extracted in the barrel 31. The carbon dioxide generated by being introduced into each of 5 is detected. The total organic carbon calculation processing unit 113 calculates the total organic carbon (TOC concentration) based on the detection result in the detection unit 7. Specifically, in the total organic carbon measuring device 1, the total organic carbon (TOC concentration) is calculated based on the relational expression of TOC (total organic carbon) = TC (total carbon) −IC (inorganic carbon). Calculated.

  When total organic carbon is measured based on such a measurement method, an error may occur in each of the measured value (IC concentration) of inorganic carbon and the measured value (TC concentration) of total carbon. And when the measured value (IC concentration) of inorganic carbon and the measured value (TC concentration) of total carbon are both large, the ratio of error to the whole becomes large, and the measurement of total organic carbon The error caused by the value (TOC concentration) becomes large.

  In the present embodiment, in the total organic carbon measuring device 1, the sample 32 and the acid solution are stored in the barrel 31, and the plunger 32 is retracted from the barrel 31 with the opening 31A closed. When carbon dioxide is extracted in the barrel 31, a large amount of inorganic carbon contained in the sample is removed. In the IC reaction section 5, carbon dioxide is generated by reacting a slight amount of inorganic carbon remaining in the sample with the acid solution. Further, in the TC combustion unit 4, carbon dioxide is generated by burning all the carbon contained in the sample. The detection unit 7 detects these carbon dioxides. The total organic carbon calculation processing unit 113 calculates the total organic carbon (TOC concentration) contained in the sample based on the detection result of the detection unit 7.

Therefore, even if an error occurs at a fixed ratio for each of the measured value of the inorganic carbon (IC concentration) and the measured value of the total carbon (TC concentration), the ratio of the error to the whole can be reduced.
As a result, the error included in the measured value of total organic carbon (TOC concentration) can be reduced.

6). In the above description, the total organic carbon measuring device 1 removes a large amount of inorganic substance from the sample by pretreatment and introduces the sample into the TC combustion unit 4 and the IC reaction unit 5 respectively. It has been described that carbon is detected and total organic carbon is calculated based on a relational expression of TOC (total organic carbon) = TC (total carbon) −IC (inorganic carbon). However, the pretreatment removes almost all of the inorganic substance from the sample and introduces the sample into the TC combustion unit 4 to detect carbon dioxide generated. TOC (total organic carbon) = TC (total carbon) The total organic carbon may be calculated based on the relational expression. In this case, the detection unit 7 detects carbon dioxide generated when the sample from which inorganic carbon has been removed by the pretreatment is introduced into the TC combustion unit 4. The total organic carbon calculation processing unit 113 calculates the total organic carbon contained in the sample based on the detection result in the detection unit 7.

  In the above description, after calculating the inorganic carbon (IC concentration) contained in the sample, the total carbon (TC concentration) contained in the sample is calculated, and then the total organic carbon (TOC concentration) is calculated. As explained. However, either the calculation of inorganic carbon (IC concentration) or the calculation of total carbon (TC concentration) may be performed first. That is, after calculating the total carbon (TC concentration) contained in the sample, the inorganic carbon (IC concentration) contained in the sample may be calculated, and then the total organic carbon (TOC concentration) may be calculated.

  In the above description, the sample and the acid solution are mixed as a pretreatment for the sample by introducing the carrier gas into the barrel 31 in a state where the sample and the acid solution are stored in the barrel 31. . However, the operation of introducing the carrier gas into the barrel 31 for mixing the sample and the acid solution can be omitted. For example, the sample and the acid solution may be mixed by repeating the operation of sucking the sample into the barrel 31 and the operation of sucking the acid solution into the barrel 31 a plurality of times.

  In the above description, the configuration in which the processing in steps S101 to S108 in FIG. 3 is automatically performed under the control of the control unit 110 has been described. However, at least a part of these steps S101 to S108 is manually performed by the user. It may be done at.

DESCRIPTION OF SYMBOLS 1 Total organic carbon measuring device 3 Syringe 4 TC combustion part 5 IC reaction part 7 Detection part 31 Barrel 31A Opening part 32 Plunger 110 Control part 112 Preprocessing control part 113 Total organic carbon calculation processing part 114 Display processing part

Claims (6)

A total organic carbon measuring device for measuring total organic carbon contained in a sample,
A TC combustion section that generates carbon dioxide by burning all the carbon contained in the sample;
A hollow barrel and a plunger that can be moved forward and backward with respect to the inside of the barrel are provided. By retracting the plunger from the inside of the barrel, a sample is sucked into the barrel from an opening formed in the barrel. A syringe for introducing the sample in the barrel into the TC combustion unit from the opening by causing the plunger to enter the barrel;
With the sample and acid solution stored in the barrel and the opening closed, a space is formed in the barrel by retracting the plunger from the barrel, and the sample reacts with the acid solution. And a pretreatment control unit for extracting carbon dioxide generated by the process into the space.   The pretreatment control unit extracts the carbon dioxide in the space by extracting the carbon dioxide into the space and then allowing the plunger to enter the barrel with the opening opened to the atmosphere. The total organic carbon measuring device according to claim 1, wherein the organic carbon measuring device is discharged into the atmosphere from the opening. An IC reaction section for generating carbon dioxide by reacting inorganic carbon contained in the sample with an acid solution;
A detection unit for detecting carbon dioxide generated by introducing the sample and the acid solution after the carbon dioxide is extracted in the barrel into the TC combustion unit and the IC reaction unit, respectively;
The total organic carbon measuring device according to claim 1, further comprising: a total organic carbon calculating unit that calculates total organic carbon contained in the sample based on a detection result in the detecting unit. . Generated in the TC combustion section that generates carbon dioxide by burning all the carbon contained in the sample, a syringe having a hollow barrel, and a plunger that can move forward and backward with respect to the inside of the barrel. A total organic carbon measurement method using a total organic carbon measuring device for measuring total organic carbon contained in a sample based on a detection result in the detection unit. And
With the sample and acid solution stored in the barrel and the opening closed, a space is formed in the barrel by retracting the plunger from the barrel, and the sample reacts with the acid solution. A pretreatment step for extracting carbon dioxide generated by the process into the space;
A sample introduction step for introducing the sample and the acid solution from which carbon dioxide has been extracted in the pretreatment step into the TC combustion unit from within the barrel;
And a total organic carbon calculation step for calculating total organic carbon contained in the sample based on a detection result of the carbon dioxide generated in the TC combustion unit in the detection unit. Method.   In the pretreatment step, after the carbon dioxide is extracted into the space, the plunger is inserted into the barrel with the opening being opened to the atmosphere, whereby the carbon dioxide in the space is opened. The total organic carbon measurement method according to claim 4, wherein the total organic carbon is discharged from the part into the atmosphere. The total organic carbon measuring device further includes an IC reaction unit that generates carbon dioxide by reacting inorganic carbon contained in a sample with an acid solution,
In the sample introduction step, carbon dioxide is generated by introducing the sample and the acid solution from which carbon dioxide has been extracted in the pretreatment step into the TC combustion unit and the IC reaction unit, respectively, from the barrel,
In the total organic carbon calculation step, the total organic carbon contained in the sample is calculated based on a detection result of the carbon dioxide generated in the TC combustion unit and the IC reaction unit in the detection unit. The total organic carbon measuring method according to claim 4 or 5.

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