JP6160529B2 - Water quality analyzer and water quality analysis method - Google Patents

Description

  The present invention relates to a water quality analyzer and a water quality analysis for measuring a component contained in a sample water by burning the sample water in a syringe and injecting the sample water into a combustion part via an injection tube. It is about the method.

A total organic carbon meter, which is an example of a water quality analyzer, can measure the concentration of carbon contained in sample water. Specifically, the TC concentration (total carbon concentration) can be measured by burning all the carbon contained in the sample water to oxidize it to CO ₂ and measuring its concentration. Also, by adding an acid solution to the sample water, CO ₂ corresponding to the amount of inorganic carbon contained in the sample water is generated, and by measuring its concentration, the IC concentration (inorganic carbon concentration) is measured. can do. Based on the TC concentration and the IC concentration, the TOC concentration (total organic carbon concentration) can be measured.

  This type of water quality analyzer includes, for example, a syringe that collects sample water and a combustion unit that combusts components contained in the sample water injected from the syringe (for example, see Patent Document 1 below). ). The syringe and the combustion part are connected by an injection tube. The amount of sample water injected from the syringe into the combustion section via the injection tube is set as a recommended injection amount calculated from the concentration of the standard sample, for example, and the user can change the recommended injection amount to an arbitrary value. it can.

Japanese Patent No. 2998601

  A tube cut into a predetermined length (for example, about 400 mm) is used as an injection tube that connects the syringe and the combustion section. That is, the conventional injection tube is prepared by cutting it to an appropriate length on the basis of the length, and both end portions thereof are connected to the syringe and the combustion portion, respectively.

  On the other hand, the amount of sample water injected from the syringe into the combustion section via the injection tube is calculated regardless of the size of the injection tube, and the injection amount can be changed to an arbitrary value by the user. . Therefore, the sample water injection amount may be smaller than the inner volume of the injection tube, or the sample water injection amount may be larger than the inner volume of the injection tube.

  Even in this case, when measuring normal sample water such as standard samples, the concentration of sample water in the syringe and injection tube is kept almost uniform. Is small. However, for example, when measuring sample water containing a highly sedimentable substance, the concentration of the sample water may be uneven in the syringe and the injection tube, which may cause a decrease in measurement accuracy. is there.

  5A and 5B are schematic cross-sectional views of a syringe 101 and an injection tube 102 for explaining a conventional aspect when injecting sample water. FIG. 5A shows a case where the sample water injection amount is smaller than the inner volume of the injection tube 102, and FIG. 5B shows a case where the sample water injection amount is larger than the inner volume of the injection tube 102.

  5A and 5B show a state in which the sample water collected in the syringe 101 is injected into the combustion section, and the syringe 101 and the injection tube 102 are filled with the sample water. That is, in FIGS. 5A and 5B, the syringe 101 and the injection tube 102 are partially hatched, but the syringe 101 and the injection tube 102 are also filled with sample water other than the hatched portions. be satisfied.

  When the injection amount of the sample water is smaller than the internal volume of the injection tube 102, only a part of the sample water in the injection tube 102 is injected into the combustion part, for example, as shown by hatching in FIG. 5A. At this time, in the case of sample water containing a substance having a high sedimentation property, there are a high concentration portion and a low concentration portion in the injection tube 102 due to the influence of resistance and gravity in the injection tube 102.

  Therefore, when only a part of the sample water as shown by hatching in FIG. 5A is injected into the combustion part and measurement is performed, there is a possibility that the repeatability may decrease or the recovery rate may vary. Here, the reduction in repeatability means that the variation in density for each measurement increases. The recovery rate is the ratio of the concentration of the sample to be measured to the concentration of the standard sample. The closer the ratio is to 100%, the higher the measurement accuracy.

  On the other hand, when the amount of sample water to be injected is larger than the internal volume of the injection tube 102, as shown by hatching in FIG. Injected into. At this time, in the case of sample water containing a substance having a high sedimentation property, the concentration of the sample water injected into the combustion part is lowered by the substance in the sample water in the upper part of the syringe 101 being settled in the syringe 101. As a result, the recovery rate may decrease.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a water quality analyzer and a water quality analysis method capable of performing measurement more stably and accurately.

The water quality analyzer according to the present invention includes a syringe, a combustion unit, an injection tube, a storage unit, and a water injection treatment unit. The syringe collects sample water. The combustion unit combusts a component contained in sample water injected from the syringe. The injection tube connects the syringe and the combustion unit. The storage unit stores an injection amount corresponding to the internal volume of the injection tube as a set value. The water injection processing unit operates the syringe based on the set value stored in the storage unit, so that the same injection amount as the internal volume of the injection tube or another internal volume of the injection tube Sample water is injected into the combustion section with an injection amount obtained by adding a predetermined amount corresponding to the internal volume of the flow path .

  According to such a structure, sample water is inject | poured into a combustion part by the injection quantity corresponding to the internal volume of an injection tube. That is, the sample water injection amount is less than the amount corresponding to the inner volume of the injection tube, and the sample water injection amount is not larger than the amount corresponding to the inner volume of the injection tube. Thereby, even when measuring sample water containing a substance having a high sedimentation property, sample water having a constant concentration as the total amount in the injection tube can be injected into the combustion section. As a result, since it is possible to prevent the repeatability from decreasing and the recovery rate from decreasing or varying, it is possible to perform measurement more stably and accurately.

  The water quality analyzer may further include a set value change processing unit that changes a set value of the amount of sample water injected into the combustion unit by the water injection processing unit based on an operation by a user.

  According to such a configuration, the user can arbitrarily change the set value of the injection amount of the sample water to be injected into the combustion unit. Therefore, for example, in the case of sample water that does not contain highly settled substances, an injection volume that is smaller than the volume corresponding to the internal volume of the injection pipe or an injection volume that is larger than the volume corresponding to the internal volume of the injection pipe is set Thus, sample water can be injected into the combustion section.

In the water quality analysis method according to the present invention, sample water is sampled in a syringe, and the sample water is injected into the combustion part via an injection pipe connecting the syringe and the combustion part, whereby components contained in the sample water are obtained. A water quality analysis method for measuring by burning, wherein the same injection volume as the internal volume of the injection pipe, or a predetermined amount corresponding to the internal volume of another flow path is added to the internal volume of the injection pipe The sample water is injected into the combustion section at a high injection amount .

  According to the present invention, the amount of sample water injected is less than the amount corresponding to the inner volume of the injection tube, or the amount of sample water injected is greater than the amount corresponding to the inner volume of the injection tube, Even when measuring sample water containing highly settled substances, sample water with a constant concentration can be injected into the combustion section as the total amount in the injection tube, making measurement more stable and accurate. be able to.

It is the schematic which showed the structural example of the water quality analyzer which concerns on one Embodiment of this invention. It is the block diagram which showed the structural example of the control part. It is a schematic sectional drawing of the flow-path switching part of FIG. 1, a syringe, and piping. It is the flowchart which showed the flow of the process by the control part at the time of setting the injection amount of the sample water to a combustion part. It is a schematic sectional drawing of the syringe and injection tube for demonstrating the conventional aspect at the time of inject | pouring sample water, and has shown the case where the injection amount of sample water is less than the internal volume of an injection tube. It is a schematic sectional drawing of the syringe and injection tube for demonstrating the conventional aspect at the time of inject | pouring sample water, and has shown the case where there is more injection amount of sample water than the internal volume of an injection tube.

  FIG. 1 is a schematic diagram showing a configuration example of a water quality analyzer according to an embodiment of the present invention. The water quality analyzer according to the present embodiment is a total organic carbon meter capable of measuring the total organic carbon concentration (TOC concentration) contained in the sample water, and only a part of the configuration is shown in FIG.

In this water quality analyzer, TC concentration (total carbon concentration) can be measured by burning all the carbon contained in the sample water to oxidize it to CO ₂ and measuring its concentration. Also, by adding an acid solution to the sample water, CO ₂ corresponding to the amount of inorganic carbon contained in the sample water is generated, and by measuring its concentration, the IC concentration (inorganic carbon concentration) is measured. can do. Then, the TOC concentration can be measured based on the TC concentration and the IC concentration. At this time, the TOC concentration can be calculated using a relational expression of TOC concentration = TC concentration−IC concentration.

  The water quality analyzer according to the present embodiment includes, for example, a flow path switching unit 1, a syringe 2, a combustion unit 3, a measurement unit 4, a control unit 5, an operation unit 6, a display unit 7, a storage unit 8, and the like. . The flow path switching unit 1 is composed of, for example, a multi-port valve having a plurality of ports 11 to 15. The port 11 is a common port, and any one of the other ports 12 to 15 can be selectively communicated with the port 11. The communication state between the ports 11 to 15 of the flow path switching unit 1 can be automatically switched, for example, by driving the motor M1. The number of ports of the flow path switching unit 1 can be set arbitrarily.

  For example, the syringe 2 includes a cylindrical body 21 and a plunger 22. The plunger 22 is inserted into the cylinder 21, and sample water can be collected in the internal space of the syringe 2 surrounded by the inner surface of the cylinder 21 and the plunger 22. At this time, the suction operation to the syringe 2 and the discharge operation from the syringe 2 are performed by displacing the plunger 22 inserted into the cylindrical body 21. The plunger 22 can be automatically performed by driving the motor M2, for example.

  In this example, a port 11 that is a common port is connected to the syringe 2. The port 12 is connected to a sample water supply unit (not shown) via a pipe 121. Therefore, the sample water can be collected in the syringe 2 (inside the cylinder 21) by displacing the plunger 22 in a state where the port 11 and the port 12 are communicated and performing a suction operation to the syringe 2. At this time, by controlling the amount of displacement of the plunger 22, the amount of sample water collected into the syringe 2 can be adjusted.

  The port 13 is connected to the combustion unit 3 via a pipe 131. After sample water is collected in the syringe 2 as described above, the port 11 and the port 13 are communicated, the plunger 22 is displaced, and the discharge operation from the syringe 2 is performed. Can be injected. At this time, the amount of sample water injected into the combustion unit 3 can be adjusted by controlling the displacement amount of the plunger 22. The pipe 131 constitutes an injection pipe that connects the syringe 2 and the combustion unit 3.

  The port 14 is connected to a cleaning liquid supply unit (not shown) via a pipe 141. Therefore, the cleaning liquid can be introduced into the syringe 2 by displacing the plunger 22 in a state where the port 11 and the port 14 are communicated and performing a suction operation to the syringe 2. For example, when the analysis using the water quality analyzer is started or ended, the inside of the syringe 2 can be cleaned with the cleaning liquid by introducing the cleaning liquid into the syringe 2.

  The port 15 is connected to the drain via a pipe 151. The remaining sample water or cleaning liquid in the syringe 2 is discharged to the drain via the pipe 151. That is, the plunger 22 is displaced while the port 11 and the port 15 are in communication and the discharge operation from the syringe 2 is performed, whereby the sample water or the cleaning liquid in the syringe 2 can be discharged to the drain via the pipe 151. it can.

  The combustion unit 3 includes a combustion tube 31 and a heating furnace 32, for example. The heating furnace 32 is composed of, for example, an electric furnace, and can heat the combustion tube 31 to a set temperature. The sample water injected from the syringe 2 into the combustion unit 3 is heated in the combustion pipe 31 and is oxidized by burning the components contained in the sample water. The component oxidized in the combustion unit 3 is sent to the measurement unit 4, and the concentration of the component is measured in the measurement unit 4.

Measurement unit 4 can be configured with a detectable infrared gas detector for example CO _2. In this case, the TC concentration can be measured by injecting sample water from the syringe 2 into the combustion unit 3 and detecting CO ₂ generated by burning all the carbon contained in the sample water by the measurement unit 4. it can. However, the measurement unit 4 is not limited to the infrared gas detector, and can be configured by other various detectors.

  A part of the sample water guided from the syringe 2 to the combustion unit 3 side via the pipe 131 can be drained from the branch pipe 132. Thereby, while guiding the sample water collected in the syringe 2 to the combustion unit 3 side, the sample water is partially injected into the combustion unit 3 and the remaining sample water is drained from the branch pipe 132. it can.

  The control unit 5 includes a CPU (Central Processing Unit), for example, and controls the operation of each unit of the water quality analyzer such as the motors M1 and M2 and the heating furnace 32 and performs processing based on the detection signal from the measurement unit 4. And so on. The operation unit 6 is for a user to perform an input operation, and includes, for example, a keyboard and a mouse. The display part 7 is comprised, for example with a liquid crystal display, and can display a measurement result etc. on a display screen. The storage unit 8 includes, for example, a hard disk and a RAM (Random Access Memory), and stores various data such as data necessary for measurement and measurement results.

  FIG. 2 is a block diagram illustrating a configuration example of the control unit 5. The control unit 5 functions as a measurement execution processing unit 51, a set value change processing unit 52, a display processing unit 53, and the like when the CPU executes a program.

  The measurement execution processing unit 51 controls the operation of the motors M1, M2, etc. during the measurement to execute the sample water or cleaning liquid suction operation and the discharge operation for the syringe 2. The measurement execution processing unit 51 includes, for example, a cleaning processing unit 511, a water sampling processing unit 512, and a water injection processing unit 513.

  The cleaning processing unit 511 performs processing for cleaning the inside of the syringe 2 using a cleaning liquid or sample water. When cleaning the inside of the syringe 2 using the cleaning liquid, the plunger 22 is displaced by driving the motor M2 while the port 11 and the port 14 are in communication with each other by driving the motor M1, and the cleaning liquid is introduced into the syringe 2. To do. Then, after the port 11 and the port 15 are communicated by driving the motor M1, the plunger 22 is displaced by driving the motor M2, and the cleaning liquid in the syringe 2 is discharged to the drain.

  On the other hand, when washing the sample 2 with sample water (co-washing), the plunger 22 is displaced by driving the motor M2 in a state where the ports 11 and 12 are in communication with each other by driving the motor M1. Sample water is introduced into the syringe 2. Then, after the port 11 and the port 15 are communicated by driving the motor M1, the plunger 22 is displaced by driving the motor M2, and the sample water in the syringe 2 is discharged to the drain.

  The water collection processing unit 512 performs a process of sampling the sample water to be injected into the combustion unit 3 into the syringe 2 by operating the syringe 2. That is, in a state where the port 11 and the port 12 are in communication with each other by driving the motor M1, the plunger 22 is displaced by driving the motor M2, and the sample water is collected into the syringe 2. At this time, the driving amount of the motor M2 is controlled in accordance with the set sampling amount of the sample water.

  The water injection processing unit 513 performs a process of injecting the sample water into the combustion unit 3 by operating the syringe 2 after sampling the sample water by the water sampling processing unit 512. That is, after the port 11 and the port 13 are communicated by driving the motor M1, the plunger 22 is displaced by driving the motor M2, and the sample water is injected into the combustion unit 3. The driving amount of the motor M2 at this time is controlled in accordance with the set sample water injection amount.

  The water injection processing unit 513 drives the motor M <b> 2 based on the recommended injection amount stored in the storage unit 8. The recommended injection amount is a set value of the injection amount of the sample water into the combustion unit 3. In this embodiment, the injection amount corresponding to the internal volume of the pipe 131 that is an injection pipe is stored in the storage unit 8 as an option. ing. The recommended injection amount may be stored in advance in the storage unit 8, or may be input from the outside during analysis and stored in the storage unit 8.

  The set value change processing unit 52 performs a process of changing the set value of the injection amount of sample water into the combustion unit 3 by the water injection processing unit 513 based on the operation of the operation unit 6 by the user. That is, not only can the sample water be injected into the combustion unit 3 based on the recommended injection amount stored in the storage unit 8, but also the sample water is injected into the combustion unit 3 at an injection amount set by a user operation. You can also. When the user changes the set value by operating the operation unit 6, the water injection processing unit 513 drives the motor M2 by the drive amount corresponding to the changed set value, so that the injection amount corresponding to the set value is reached. Thus, sample water is injected into the combustion section 3.

  The display processing unit 53 controls display on the display unit 7. The TC concentration, IC concentration, TOC concentration, and the like measured by the measurement unit 4 are displayed on the display unit 7 as measurement results by the processing of the display processing unit 53. The display processing unit 53 can display not only the measurement result in the measurement unit 4 but also various setting screens on the display unit 7 such as a setting screen when changing the set value of the injection amount of the sample water, for example. .

  FIG. 3 is a schematic cross-sectional view of the flow path switching unit 1, the syringe 2, and the pipe 131 of FIG. In FIG. 3, the state at the time of inject | pouring the sample water sampled in the syringe 2 (inside the cylinder 21) to the combustion part 3 is shown, and the inside of the syringe 2 and the piping 131 are filled with sample water. . That is, in FIG. 3, the piping 131 is hatched, but the syringe 2 and the piping 131 are filled with sample water other than the hatched portions.

  As described above, in the present embodiment, the injection amount corresponding to the internal volume of the pipe 131 that is an injection pipe is stored in the storage unit 8 as the recommended injection amount. Therefore, when the water injection processing unit 513 operates the syringe 2 based on the recommended injection amount stored in the storage unit 8 to inject sample water into the combustion unit 3, it is indicated by hatching in FIG. The sample water is injected at an injection amount corresponding to the internal volume of the pipe 131.

  More sample water than the recommended injection amount is collected in the syringe 2 and a part thereof is injected into the combustion unit 3. Specifically, while the sample water in the syringe 2 is guided to the combustion unit 3 side through the pipe 131, the supernatant portion in the syringe 2 is first drained through the branch pipe 132 (see FIG. 1). Thereafter, of the sample water guided to the combustion unit 3 side, sample water in an amount corresponding to the internal volume of the pipe 131 is injected into the combustion unit 3, and the remaining sample water is again drained through the branch pipe 132. The

  The injection amount corresponding to the internal volume of the pipe 131 may be the same as the internal volume from one end to the other end of the pipe 131, or a value obtained by adding or subtracting a predetermined amount to the internal volume. There may be. That is, the injection amount corresponding to the internal volume of the pipe 131 may be an injection amount set based on the internal volume from one end to the other end of the pipe 131. Therefore, for example, the flow path between the pipe 131 and the combustion section 3 as well as the flow path between the syringe 2 and the pipe 131 such as the flow path 10 (see FIG. 3) of the sample water in the flow path switching section 1. For example, a value obtained by adding a predetermined amount corresponding to the internal volume of another flow path may be used.

  FIG. 4 is a flowchart showing the flow of processing by the control unit 5 when setting the amount of sample water to be injected into the combustion unit 3. In the present embodiment, the user determines whether or not to use a prescribed pipe 131 having a known internal volume (for example, 80 μl), and when using the prescribed pipe 131, the syringe 2 and the combustion unit are used using the prescribed pipe 131. 3 are connected.

  In this way, when the syringe 2 and the combustion unit 3 are connected using the specified pipe 131, the user operates the operation unit 6 to use the specified pipe 131 on the setting screen. A selection is made (Yes in step S101). In this case, the recommended injection amount stored in the storage unit 8 as the injection amount corresponding to the internal volume of the pipe 131 is set as the injection amount of the sample water into the combustion unit 3 (step S102).

  Even when the use of the prescribed pipe 131 is selected, when the user changes the set value by operating the operation unit 6, the set value is given priority. That is, when the setting value of the injection amount is changed by the user's operation (Yes in Step S103), the injection amount of the sample water into the combustion unit 3 is set to the changed injection amount (Step S104).

  After the sample water injection amount to the combustion unit 3 is set in this manner, when the analysis is started by the user operating the operation unit 6 (Yes in step S105), the set injection amount The analysis is performed (step S106). Thus, the water injection processing unit 513 drives the motor M2 by the driving amount corresponding to the set value, and the sample water is injected into the combustion unit 3 at the injection amount corresponding to the set value.

  Thus, in the present embodiment, when the specified pipe 131 is selected as the injection pipe, the sample water is injected into the combustion unit 3 with an injection amount corresponding to the internal volume of the pipe 131. That is, the sample water injection amount is less than the amount corresponding to the internal volume of the pipe 131, and the sample water injection amount is not larger than the amount corresponding to the internal volume of the pipe 131. As a result, even when sample water containing a highly sedimentable substance is measured, sample water having a constant concentration is injected into the combustion section 3 as the total amount in the pipe 131 as shown by hatching in FIG. be able to. As a result, since it is possible to prevent the repeatability from decreasing and the recovery rate from decreasing or varying, it is possible to perform measurement more stably and accurately.

  In the present embodiment, the user can arbitrarily change the set value of the injection amount of the sample water to be injected into the combustion unit 3 by operating the operation unit 6. Therefore, for example, in the case of sample water that does not contain a substance having a high sedimentation property, an injection amount smaller than the amount corresponding to the internal volume of the pipe 131 or an injection amount larger than the amount corresponding to the internal volume of the pipe 131 is set. Thus, the sample water can be injected into the combustion unit 3.

  In the above embodiment, the configuration in which the user can change the set value of the amount of sample water injected into the combustion unit 3 by the water injection processing unit 513 has been described. However, the configuration is not limited to such a configuration, and the configuration may be such that the sample water can be injected into the combustion unit 3 only with an injection amount corresponding to the internal volume of the pipe 131 as an injection tube.

  Moreover, in the above embodiment, the total organic carbon meter was demonstrated as an example of a water quality analyzer. However, the present invention is not limited to a total organic carbon meter, but can be applied to other water quality analyzers including a syringe, a combustion unit, and a measurement unit.

DESCRIPTION OF SYMBOLS 1 Flow path switching part 2 Syringe 3 Combustion part 4 Measurement part 5 Control part 6 Operation part 7 Display part 8 Memory | storage part 11-15 Port 21 Tubular body 22 Plunger 31 Combustion pipe 32 Heating furnace 51 Measurement execution process part 52 Setting value change process Section 53 Display processing section 121 Piping 131 Piping 132 Branch pipe 141 Piping 151 Piping 511 Cleaning processing section 512 Water sampling processing section 513 Water injection processing section M1, M2 Motor

Claims (3)

A syringe for collecting sample water;
A combustion section for combusting components contained in the sample water injected from the syringe;
An injection pipe connecting the syringe and the combustion section;
A storage unit that stores an injection amount corresponding to the internal volume of the injection tube as a set value;
By operating the syringe based on the set value stored in the storage unit, the same injection volume as the internal volume of the injection tube, or the internal volume of the other flow path to the internal volume of the injection tube A water quality analyzer comprising: a water injection processing unit for injecting sample water into the combustion unit at an injection amount to which a corresponding predetermined amount is added .   The water quality analysis according to claim 1, further comprising a set value change processing unit that changes a set value of a sample water injection amount into the combustion unit by the water injection processing unit based on an operation by a user. Total. The sample water is water sampling in the syringe, by injecting the sample water to the combustion section via an injection tube connecting the syringe and combustion unit, water for measuring by burning components contained in the sample water An analysis method,
Sample water is injected into the combustion section at the same injection volume as the internal volume of the injection pipe or an injection volume obtained by adding a predetermined amount corresponding to the internal volume of another flow path to the internal volume of the injection pipe . Water quality analysis method characterized by this.

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