JP2006047323A - Measurement/liquid feed mechanism for aqueous solution for analysis and water quality analyzer using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measurement/liquid feed mechanism for an aqueous solution for analysis allowing connection of many aqueous solution samples, capable of performing automation of a preprocess, accurately measuring sample water or a reagent, and feeding liquid. <P>SOLUTION: A syringe pump 16 is connected to a common port A1 of a multiport valve A, and a common port B1 of a multiport valve B is connected to one port of distribution ports A2 of the multiport valve A through a communication tube 19. Four distribution ports B2 of the multiport valve B are respectively connected with four different sample flow passages. The residual distribution ports A2 except the distribution port A2 connected with the communication tube 19 of the multiport valve A are connected with a flow passage communicating with the reagent such as hydrochloric acid or an alkaline solution, and a flow passage or the like communicating with a TC oxidation reaction part 2 or an IC reaction part 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to pollutants contained in environmental water such as waste water from factories and business establishments, rivers, lakes and marshes where water pollution is serious, such as total organic carbon, trace amounts of nitrogen compounds and phosphorus compounds. The present invention relates to a measuring and feeding mechanism for an aqueous solution for analysis that is most suitable for a water quality analyzer for measuring the concentration, and a water quality analyzer using the same.

As a water quality analyzer, for example, as a water quality analyzer for examining the degree of water pollution in rivers and lakes, a TOC meter is used to measure total organic carbon (TOC) contained in the water, and nitrogen in water There is a total nitrogen (TN) / total phosphorus (TP) meter to analyze compounds, phosphorus compounds.

The TOC meter includes a reaction unit including at least a total carbon oxidation reaction unit that converts total carbon in an aqueous solution sample into carbon dioxide (CO ₂ ), and an automatic sample injector that collects a predetermined amount of the aqueous solution sample and injects it into the reaction unit. A carrier gas supply unit that supplies a carrier gas to the reaction unit, and a CO ₂ detection unit that detects CO ₂ sent together with the carrier gas from the reaction unit. The automatic sample injector includes a syringe-type metering pump equipped with a plunger for metering and feeding an aqueous solution sample, a driving means for driving the plunger in the vertical direction, and a syringe-type metering pump. And a multi-port valve for switching and connecting to several channels including an aqueous solution sample supply channel. The multi-port valve has one common port and a plurality of distribution ports. A syringe-type metering pump is connected to the common port, and the distribution port has a flow path leading to an aqueous solution sample, reaction unit, standard sample, diluent, etc. Connected. Then, at each stage of measurement, each distribution port is appropriately switched and connected to the common port.

In Japan, methods for analyzing nitrogen compounds and phosphorus compounds in water are officially standardized by JIS K0102 and Environmental Agency Notification 140. Nitrogen compounds in water exist as nitrate ions, nitrite ions, ammonium ions or organic nitrogen. In these all-nitrogen analysis methods for measuring all nitrogen in water, all nitrogen compounds are changed to nitrate ions for measurement, but ammonium ions and organic nitrogen are not easily oxidized and decomposed into nitrate ions. Therefore, in the total nitrogen measurement, an alkaline potassium peroxodisulfate solution is added to the sample water as an oxidizing agent and heated at 120 ° C. for 30 minutes to oxidatively decompose all nitrogen compounds into nitrate ions. After cooling it, the pH is adjusted to 2-3, and the ultraviolet absorbance at a wavelength of 220 nm by nitrate ions is measured.

On the other hand, phosphorus compounds in water exist as phosphate ions, hydrolyzable phosphorus, or organic phosphorus. In total phosphorus measurement, a potassium peroxodisulfate solution is added as an oxidizing agent in a neutral state, and all phosphorus compounds are oxidatively decomposed into phosphate ions by heating at 120 ° C. for 30 minutes. Since phosphate ions do not have specific light absorption, in order to measure phosphate ions, an ammonium molybdate solution and an L-ascorbic acid solution are added as color formers after cooling to cause color development, and the absorbance at a wavelength of 880 nm is measured. Measuring.

In this way, in a TN / TP meter that measures total nitrogen (TN) and total phosphorus (TP) in water by absorptiometry, an oxidizing agent (potassium peroxodisulfate solution) is added as a pretreatment, It is necessary to oxidatively decompose the added sample water to generate nitrogen compounds into nitrate ions and phosphorus compounds into phosphate ions. For this purpose, (1) aqueous solution samples, oxidizing agents, acid for pH adjustment, color development (2) Weighing and feeding the measured aqueous solution samples and reagents to the oxidation reaction unit, and feeding the oxidatively decomposed aqueous solution sample to the absorbance measurement unit, ( 3) It is essential to mix and stir the aqueous solution sample with each reagent. For this purpose, measuring tubes are used for measuring aqueous solution samples and reagents such as oxidants, color formers, and acids, and pumps and valves are used for feeding measured aqueous solution samples and switching flow paths. ing.
JP-A-10-160726 JP 58-201064 A

A sample injector with a syringe-type metering pump connected to a multi-port valve and its common port is provided for metering and feeding an aqueous solution sample (hereinafter referred to as “sample water” or “sample” as appropriate) and for switching the flow path. In the TOC system, there is an upper limit to the number of distribution ports that the multiport valve has, and usually the maximum is about eight.

Therefore, when sample water is collected and analyzed through the distribution port of the multi-port valve, the number of samples that can be connected is limited, so there is a limit to automatically and continuously analyzing a plurality of sample water. In addition, depending on the analysis method, a standard addition method in which a standard sample is added to the sample water for analysis is employed. In this case, in order to automatically add the standard sample, a flow path connected to the standard sample is used. Must be connected to the distribution port, and the choice should be made between reducing the number of connected samples and giving up the automatic addition of standard samples.

Similarly, depending on the analytical method, pretreatment such as adjusting the pH of the sample water or venting is required, but all the flow paths connecting to the acid solution, the alkali solution and the gas for venting are connected to the distribution port. This is practically impossible. When pretreatment is required, the sample water is separately pretreated, and then the flow path leading to the pretreated sample water is connected to the distribution port of the multiport valve.

In TN / TP measurement, as described above, sample water and various reagents are metered, sample water and each reagent are mixed, sample water is stirred after the reagent is mixed, and oxidation reaction parts such as sample water and reagent are measured. In conventional TN / TP meters, the sample water, oxidizing agent, color former, acid, and other reagents are measured using a measuring tube, and the measured sample water and reagent are sent. The liquid and flow path are switched using a pump and a valve. From the analysis method of TN / TP, due to the use of a large number of reagents, the sample water and each reagent are measured, and the measured sample water and reagents are measured. In order to transfer the liquid to the flow path such as an oxidation reaction section such as TN / TP, and to switch the flow path, a large number of measuring tubes, pumps and valves are required (in conventional TN / TP meters, (Measuring pipe: 12 pieces, pump: 9 pieces, valve: 23 solenoid valves, 16 pinch valves, 39 pieces in total)Further, if a flow path for dilution / washing of sample water or calibration with standard water is provided, the number of measuring tubes, pumps, and valves is further increased, and the flow path configuration is complicated. In addition, since the flow path becomes long, the price of the apparatus increases, the number of failure points and the failure frequency increase, and there is a problem that repair and maintenance work become complicated.

Furthermore, if the flow path becomes longer, it takes time to transfer the sample, etc., and as a result, the measurement time becomes longer and the response becomes slow, while contamination and clogging of the sample are likely to occur during transfer. There was a problem that the failure was likely to occur frequently.
In addition, the measurement of the reagent in the measuring tube is carried out by an overflow method in which the reagent overflows from a predetermined volume of the container, or by a predetermined amount of sucking or the like. In general, it cannot be reused, the consumption of reagents is inevitably increased, and the running cost is unreasonable. Also, if the dilution rate is changed, the dilution device itself must be replaced because the dilution rate is fixed. Furthermore, there is a problem that the dilution of the sample water necessary for measuring the high-concentration sample water requires a dedicated diluter.

In order to solve the above-mentioned problems, the present invention can connect a large number of aqueous solution samples, enables automation of pretreatment of sample water, and can accurately collect and measure sample water and reagents without waste. In addition, the analysis solution measuring and feeding mechanism and the analysis solution measuring and feeding mechanism can be simplified by using a sample injector, thereby reducing failure. The object is to provide a water quality analyzer such as a low-cost TOC meter or TN / TP meter with excellent responsiveness.

In order to solve the above-described problems, a measuring / liquid feeding mechanism for an aqueous solution for analysis according to the present invention is configured as follows. That is, at least two multi-port valves having one common port and a plurality of distribution ports, a motor connected to each multi-port valve and switching the connection relationship between the common port and the distribution port, and each motor And a CPU for synchronously controlling the above. A syringe-type metering pump for measuring / collecting and feeding an aqueous solution is connected to a common port of one multiport valve, and one of the distribution ports of the multiport valve to which the pump is connected is connected to the other multiport valve. Connected to a common port. And the other distribution ports of both correspond to each port according to the purpose of analysis including the sample water, oxidizing agent, coloring agent, acid and other reagents, as well as the flow path of standard solution, diluent, etc. Each necessary flow path is connected, and each flow path is configured to be connectable to a common port of one multi-port valve to which a syringe type metering pump is connected via a corresponding distribution port.

A multi-port where a syringe-type metering pump is connected to a common port, such as a common port of two or more other multi-port valves is connected to a distribution port of a multi-port valve to which a syringe-type metering pump is connected to a common port Syringe-type metering pump connected to a common port, such as a parallel connection of a plurality of other multi-port valves to a valve, or one of the distribution ports of the other multi-port valve to a common port of another multi-port valve It is also possible to connect a plurality of other multiport valves in series to the multiport valve to which is connected, and in this way, a larger number of channels such as the required number of sample water and reagents depending on the analysis purpose Can be connected.

If the analytical aqueous solution metering / feeding mechanism having the above configuration is an automatic sample injector in a TOC meter, the common multiport valve of one multiport valve connected to a syringe-type metering pump is connected to a common port. Connect the flow path to the standard solution and the acid solution, alkali solution, etc. necessary for pretreatment to multiple distribution ports other than connecting to the port, and connect the common port to one distribution port of one multi-port valve A flow path connecting to a plurality of sample waters to be analyzed can be connected to a plurality of distribution ports of the other multi-port valve, and in addition to one multi-port valve having a syringe-type metering pump connected to a common port. By connecting two or more multi-port valves in parallel and / or in series, sample water, standard solution, The number of acid solutions, alkali solutions, and other reagents required for pretreatment is virtually unlimited, pretreatment can be automated for the required number of samples, and pretreated sample water is used in the measurement section. It becomes possible to supply.

Also, if a gas introduction flow path is formed in a syringe-type metering pump connected to the common port of one multi-port valve and the introduction flow path is connected to a gas supply source, the sample water necessary for the analysis method is obtained. It is possible to automatically perform pretreatment such as aeration and stirring of the sample water and the reagent.

Furthermore, if the analytical aqueous solution metering / feeding mechanism having the above configuration is used for a sample injector in a TN / TP meter, a syringe is connected to each of the plurality of distribution ports of one and the other multiport valves, for example, a common port. An oxidizing agent (potassium peroxodisulfate solution), an acid for pH adjustment, a plurality of distribution ports other than connecting to the common port of the other multiport valve of one multiport valve to which a type metering pump is connected, Each flow path connected to a reagent such as an ammonium molybdate solution and an L-ascorbic acid solution as a color former is connected, and a common port is connected to one distribution port of one multiport valve. Sample flow, dilution water, calibration liquid (standard water or span liquid) to be analyzed in multiple distribution ports, and each flow path connected to the absorbance measurement unit Furthermore, by connecting two or more multi-port valves in parallel and / or in series to one multi-port valve having a syringe-type metering pump connected to a common port, a large number of samples can be connected. On the other hand, the necessary pretreatment is automatically performed, and the pretreated sample water can be supplied to the absorbance measurement unit.

At that time, only by connecting each flow path to each distribution port of the corresponding multi-port valve, switching of the flow path and measuring / feeding of sample water, reagent, etc. are performed with the multi-port valve and syringe type measurement connected to it. Since it can be performed by a pump, the flow path configuration and operation can be greatly simplified as compared with a conventional TN / TP meter. As a result, the cost can be greatly reduced and no trouble occurs. In addition, since the flow path can be shortened, the responsiveness is increased accordingly. Thereby, a low-cost TP / TN meter with few failures and excellent responsiveness can be obtained. In addition, the reagent is measured by a syringe-type metering pump and a predetermined volume is measured and fed, so there is no wasteful consumption and the running cost can be reduced. Furthermore, it is possible to dilute the sample water at an arbitrary dilution rate by adjusting the syringe type metering pump.

According to the aqueous solution metering / liquid feeding mechanism of the present invention, it is possible to connect a large number of aqueous solution samples, automate pretreatment and measurement of those samples, and accurately measure and feed the sample water and reagents. It becomes possible. In addition, if the measuring / feeding mechanism of the aqueous solution sample of the present invention is used for the sample injector of the water quality analyzer, the measuring / feeding mechanism and the flow path configuration are simplified, the flow path is short, and the water quality is easy to maintain with few failures. An analysis device is obtained.

In particular, when used as a sample injector for a TN / TP meter, the flow path can be dramatically reduced in number of parts compared to conventional devices of this type, which are constructed with a large number of measuring tubes, liquid pumps and valves. As a result, a TN / TP meter without failure can be obtained. In addition, many reagents are used in the TN / TP meter. However, since accurate measurement is possible, it is possible to minimize the consumption of the reagent, and in addition to shortening the flow path, the responsiveness can be improved. An excellent low-cost TN / TP meter can be obtained. Furthermore, a water quality analyzer such as a TOC meter and a TP / TN meter capable of diluting from a low magnification to a high magnification without providing a dedicated diluter can be obtained.

Embodiments of the present invention will be described below with reference to examples shown in the drawings. FIG. 1 is a schematic configuration diagram of an entire water quality analyzer as an example of a total organic carbon (TOC) meter in which an aqueous solution metering / liquid feeding mechanism according to the present invention is applied to an automatic sample injector. As shown in the figure, the TOC meter includes a TC oxidation reaction unit 2 that converts TC (total carbon) in an aqueous solution sample into CO ₂ (carbon dioxide), and IC (inorganic carbon) in the aqueous solution sample into CO ₂ . A sample injector 15 is provided in order to collect an IC reaction part 6 to be converted and a certain amount of the aqueous solution sample and guide it to the TC oxidation reaction part 2 or the IC reaction part 6.

The sample injector 15 includes first and second multiport valves having a common port and a plurality of distribution ports (in the embodiment, the first multiport valve is an 8-port valve and the second multiport valve is a 4-port valve). ) Consists of A and B and a syringe-type metering pump (hereinafter referred to as a syringe pump) 16, and the syringe pump 16 is connected to the common port A1 of the first multiport valve A, and the second multiport valve The common port B1 of B is connected to one of the distribution ports A2 of the first multiport valve A via the communication pipe 19.

The syringe pump 16 includes a syringe body 17 having a predetermined internal volume, and a plunger 18 driven by a pulse motor shown in FIG. A gas flow path 20 connected to the pump is connected, and air or inert gas for stirring or aeration treatment is supplied at a predetermined timing into the syringe body 17 via the flow path 20. Yes. The gas flow path 20 connected to the syringe pump pump 16 may be provided in the plunger 18 instead of being provided in the syringe body 17.

On the other hand, the four distribution ports B2 of the second multiport valve B are connected to sample flow paths connected to four different sample containers, respectively, and the communication pipe 19 of the first multiport valve A is connected. The remaining seven distribution ports A2 other than the above contain a flow path connected to a standard sample, a flow path connected to dilution water that also serves as washing water, and an acid (usually 1 to 2 N hydrochloric acid). The flow path connected to the acid container, the flow path connected to the sample inlet (sample introduction section) of the TC oxidation reaction section 2 described later, the flow path connected to the IC reaction section 6, and the flow path connected to the alkaline container are connected to each other. The remaining one distribution port is open to the atmosphere as a gas introduction / discharge path.

Then, by being driven by a pulse motor (not shown) separately provided in the first and second multiport valves A and B, the distribution ports A2 of the first and second multiport valves A and B, One of the ports B2 is selectively connected to the common port A1 of the first multiport valve A, and accordingly, each of the flow paths is connected to the first multiport valve A via its corresponding distribution port. Connected to the common port A1, that is, to the syringe pump 16, sample water, hydrochloric acid, dilution water, etc. from the sample flow path are weighed and collected by the micro syringe 16 and sent to the TC oxidation reaction unit 2 or IC reaction unit 6. The Each pulse motor and agitation pump described above are controlled by the CPU.

The TC oxidation reaction section 2 is provided with a TC combustion pipe 4 filled with an oxidation catalyst, and a heating furnace 5 is provided outside the TC combustion pipe 4 in order to heat the TC combustion pipe 4. Reference numeral 3 denotes a TC sample inlet of the TC combustion pipe 4, and sample water is injected into the TC combustion pipe 4 via the TC sample inlet 3 connected to the corresponding distribution port of the second multi-valve, and as carrier gas. Pure oxygen gas or gas containing oxygen (for example, high purity air excluding carbon) is supplied from the TC sample inlet 3 to the TC combustion tube 4. The outlet of the TC oxidation reaction unit 2 is connected to the dehumidification and dust removal unit 11 via the IC reaction unit 6, and is connected from the dehumidification and dust removal unit 11 to the CO ₂ detection unit 12 of the NDIR (non-dispersive infrared spectrophotometer).

The IC reaction unit 6 is provided with an IC reactor 8 filled with an IC reaction solution. From the sample injector 15 via the IC sample inlet 7 connected to the corresponding distribution port in the first multi-valve A, Sample water is injected. In the IC reactor 8, IC in the injected aqueous solution sample is generated as CO _2, and is guided from the dehumidification / dust removal unit 11 to the CO ₂ detection unit 12 by the carrier gas supplied through the TC oxidation reaction unit 2. In the figure, 10 is an IC reaction solution supplier for supplying an IC reaction solution to the IC reactor 8, and 9 is a drain valve for discharging the IC reaction solution of the IC reactor 8.

The TOC measurement by the TOC meter having the above configuration is performed as follows.
(B) TC measurement One of the distribution ports B2 connected to the sample channel in the second multiport valve B is connected to the common port B1, and the distribution port is connected to the communication pipe 19 in the first multiport valve A. A2 is connected to the common port A1, and sample water to be measured is sucked and collected in the syringe body 17 of the syringe pump 16 in a necessary amount, and then the common port A1 is connected to the TC oxidation reaction unit 2 in the first multiport valve A. The plunger 18 is raised by connecting to a flow path connected to the sample injection port (sample introduction portion) 2, and a predetermined amount of sample water in the syringe body 17 is injected into the combustion tube 4. The sample water burned in the combustion tube 4 becomes a combustion gas in which the carbon component is converted to CO ₂ , and the moisture content and the like are removed by the dehumidification / dust removal unit 11 through the IC reaction unit 6 and introduced into the CO ₂ detection unit 12. Thus, the amount of transmitted light is detected, and the data processor 13 calculates the TC concentration. The combustion gas converted into CO ₂ by the combustion tube 4 is introduced into the CO ₂ detection unit 12 through the dehumidification / dust removal unit 11 by the carrier gas supplied from the TC sample inlet 3.

(B) IC measurement and TOC measurement As in the case of TC measurement, the sample water to be measured is weighed and collected in the syringe body 17 and then the common port A1 is connected to the sample of the IC reaction unit 6 in the first multiport valve A. The plunger 18 is raised by connecting to the distribution port A2 connected to the inlet (sample introduction part) 7, and a predetermined amount of sample water in the syringe body 17 is injected into the IC reaction tube 8. The IC component in the sample water is converted into CO ₂ by the IC reaction tube 8 and is introduced into the CO ₂ detection unit 12 through the dehumidification and dust removal unit 11 by the carrier gas introduced through the TC reaction unit 2 to detect the amount of transmitted light. Then, the IC concentration is calculated by the data processing unit 13, and the TOC concentration is obtained from the difference from the previously obtained TC concentration. In the second multiport valve B, the distribution port B2 connected to each sample flow path is sequentially switched to the common port B1 and the above operation is repeated, so that a plurality of (in the embodiment) connected to the distribution port B2 of the second multiport valve B 4) TOC concentration in sample water can be measured continuously.

Next, various types of processing when sample water pretreatment is required will be described.
<1. Acidification> (1) After the distribution port A2 connected to the acid flow path in the first multiport valve A is connected to the common port A1, the plunger 18 of the plunger pump 16 is pulled down and placed in the cylinder body 17. A fixed amount of acid solution is aspirated.
(2) In the first multiport valve A, the distribution port A1 connected to the communication pipe 19 is connected to the common port A1 to which the syringe pump 16 is connected. In the second multiport valve B, the common port B1 is the first port. To the distribution port B2 connected to the sample flow path. In this state, the plunger 18 is pushed upward, and a certain amount of the acid solution in the syringe body 17 is added to the first sample. Subsequently, in the second multi-port valve B, the distribution port B2 connected to the second, third, and fourth sample flow paths is sequentially switched to the common port B1, and the same operation is repeated, so that each sample is repeated. A certain amount of acid solution is added to the water.

<2. Alkalization> (1) After the distribution port A2 connected to the flow path of the alkaline solution in the first multiport valve A is connected to the common port A1, the plunger 18 of the plunger pump 16 is pulled down into the cylinder body 17. A predetermined amount of the alkaline solution is sucked, and thereafter, a certain amount of the alkaline solution is added to each sample water by the same operation as the addition of the acid solution.

(3. Addition of standard sample)
(1) In the first multi-port valve A, after connecting to the flow path of the standard sample and connecting the distribution port A2 to the common port A1, the plunger 18 of the plunger pump 16 is pulled down to reach a predetermined amount in the cylinder body 17. The standard sample is aspirated, and thereafter, a certain amount of the standard sample is added to each sample water by the same operation as the acid solution addition.

(4. Dilution)
(1) After the distribution port A2 connected to the flow path of the diluent in the first multiport valve A is connected to the common port A1, the plunger 18 of the plunger pump 16 is pulled down and the diluent is sucked into the cylinder body 17. Thereafter, in a similar operation to the addition of the acid solution, a predetermined amount of dilution liquid determined by the dilution rate is added to each sample water, and diluted at a constant rate.

(5. Ventilation)
(1) In the first multiport valve A, the distribution port A2 connected to the atmosphere is connected to the common port A1, and the plunger 18 is pulled down to a position where it is connected to the gas flow path 20 connected to the stirring pump formed in the syringe body 17. It is done.

(2) In the first multiport valve A, the distribution port A2 connected to the communication pipe 19 is connected to the common port A1 connected to the syringe pump 16, and in the second multiport valve B, the common port B1 is the first port. To the distribution port B2 connected to the sample flow path. In this state, the agitation pump is driven, gas is introduced into the sample water through the gas flow path 20, and gas aeration is performed for a certain time. Subsequently, the common port B1 in the second multiport valve B is sequentially switched so as to be connected to the distribution port B2 connected to each sample flow path, and the same operation is repeated, so that each sample water is constant. Aeration of time takes place. If it is necessary to stir the sample solution uniformly after adding an acid solution, an alkali solution, etc. to the sample water, the gas is sequentially added to each sample water by the same operation as the above-mentioned gas aeration process. It can stir by introducing and bubbling.

In addition, after the necessary pretreatment is performed, the same operation as (b) TC measurement, (b) IC measurement, and TOC measurement is repeated, thereby continuously measuring the TOC concentration in each sample water. be able to. In the embodiment, the carrier gas and the ventilation gas are supplied from separate supply sources, but may be supplied from a common gas source.

Next, another embodiment of FIG. 2 will be described. FIG. 2 is a schematic configuration diagram of a water quality analyzer as a total nitrogen (TN) / total phosphorus (TP) meter of another example in which the aqueous solution measuring and liquid feeding mechanism according to the present invention is used as a sample injector. As shown in the figure, the TN / TP meter is provided with an oxidation reactor 21 and an absorbance measuring unit 23 for measuring the absorbance of sample water as a measuring unit. A sample injector 15 is provided in order to measure and sample a certain amount of sample water or reagent and lead it to the measurement cell 23a of the oxidation reactor 21 or the absorbance measurement unit 23.

As in FIG. 1, the sample injector 15 is a first and second multiport valve having a common port and a plurality of distribution ports (in the embodiment, both the first and second multiport valves are 8-port valves). The syringe pump 16 is connected to the common port A1 of the first multiport valve A, and the common port B1 of the second multiport valve B is connected to the communication pipe 19. To one of the distribution ports A2 of the first multiport valve A. Similarly, the syringe pump 16 is composed of a syringe body 17 having a predetermined internal volume and a plunger 18 driven by a pulse motor shown in the figure, which is slidably engaged in the body 17. A gas flow path 20 connected to a stirring pump is connected to the main body 17, and air or inert gas for agitation or aeration treatment is supplied to the syringe main body 17 through the flow path 20 at a predetermined timing. It is like that.

To each distribution port A2 of the first multi-port valve A, a flow path connected to sodium hydroxide (NaOH), a flow path connected to potassium peroxodisulfate solution (oxidant), added to adjust the ph value A channel connected to hydrochloric acid (HCl), a channel connected to sulfuric acid, a channel connected to an ammonium molybdate solution, and a channel connected to an L-ascorbic acid solution are connected to each other, and the remaining one distribution port is a gas introduction / discharge channel As open to the atmosphere. On the other hand, each distribution port B2 of the second multiport valve B has a flow path connected to the sample 1, a flow path connected to the sample 2, a flow path connected to the calibration solution, a flow path connected to the oxidation reactor 21, and dilution water. , A channel connected to the measurement cell 23a of the absorbance measurement unit 23, and a channel connected to the standard sample are connected to each other, and the remaining one port is a drain port.

The first and second multiport valves A and B are driven by a pulse motor (not shown), so that one of the distribution ports A2 and B2 of the first and second multiport valves A and B is provided. Are selectively connected to the common port A1 of the first multi-port valve A, and accordingly, each flow path is connected to the common port A1 of the first multi-port valve A via its corresponding distribution port, that is, The sample water from the sample flow path and the reagent such as hydrochloric acid, oxidant, and color developer are weighed and collected by the microsyringe 16 and sent to the oxidation reactor 21 or the measurement cell 23a. The Each of the pulse motors and the agitation pump is controlled by a control / data processing unit mainly composed of a CPU described later.

The oxidation reactor 21 irradiates or heats an aqueous solution sample to which a potassium peroxodisulfate solution (oxidant) is added or heats it to cause an oxidation reaction (decomposition). In this oxidation reactor, nitrogen compounds in sample water And phosphorus compounds are oxidatively decomposed into nitrate ions and phosphate ions, respectively. The output of the absorbance measurement unit 23 is connected to the control / data processing unit 24. The control / data processing unit 24 processes the output of the absorbance measurement unit 23 to obtain the TN concentration or TP concentration, or the sample injector. The operation of the multiport valves A and B, and the syringe pump 16 and the agitation pump constituting the above are controlled. The control / data processing unit 24 is connected to a display unit 25, a keyboard (not shown), a recorder, and the like.

Next, a procedure for measuring the TN concentration and the TP concentration in the sample water will be described.
(A) TN measurement a) Under the control of the control / data processing unit 24, one of the distribution ports B2 connected to the flow path of the sample 1 or the sample 2 in the second multiport valve B is connected to the common port B1, In addition, the distribution port A2 to which the communication pipe 19 is connected in the first multiport valve A is connected to the common port A1 to which the syringe pump 16 is connected, and the sample water to be measured is sucked into the syringe pump 16 by a necessary amount. When a predetermined amount of dilution rate is set after being collected, the distribution port B2 connected to the dilution water flow path in the second multiport valve B is connected to the common port B1 and sucked into the syringe pump 16. A predetermined amount of dilution water is added to the sample water.

b) In the first multiport valve A, the distribution port A2 connected to the potassium peroxodisulfate solution (oxidizing agent) and the NaOH flow path is sequentially connected to the common port A1 to the diluted sample water in the syringe pump 16; A predetermined amount of potassium peroxodisulfate and NaOH are added.

c) After connecting the distribution port A2 connected to the atmosphere to the common port A1 in the first multiport valve A, the agitation pump is driven to introduce gas into the syringe pump 16 through the gas flow path 20, and the inside of the pump 16 After stirring the sample water to which the oxidizing agent or the like of the first sample is added, the distribution port A2 to which the communication pipe 19 is connected in the first multiport valve A is connected to the common port A1 to which the syringe pump 16 is connected. 2 Distributing port B2 connected to oxidation reactor 21 in multiport valve B is connected to common port B1, and sample water added with potassium peroxosulfate and NaOH in syringe pump 16 that has been homogenized by stirring is used in oxidation reactor. The nitrogen compound in the sample water is decomposed into nitrate ions by being irradiated with ultraviolet rays for a predetermined time or heated.

In the above description, a predetermined amount of sample water, dilution water, potassium peroxodisulfate, and NaOH are respectively sucked into the syringe pump 16 and the mixed solution is discharged to the oxidation reactor 21. After connecting the pump 16 to the sample flow path and sucking a predetermined amount of sample water, the syringe pump 16 is connected to the flow path of the oxidation reactor 21, and the sample water in the syringe pump 16 is transferred to the oxidation reactor 21. Then, the syringe pump 16 is connected to the flow path of the dilution water to suck a predetermined amount of dilution water, and then the syringe pump 16 is connected to the flow path of the oxidation reactor 21 to dilute in the syringe pump 16 During the sequential switching of the syringe pump 16 to the sample flow path, the dilution water flow path, the peroxo potassium dioxide flow path, and the NaOH water flow path, such as discharging water into the oxidation reactor 21, the oxidation reactor 21 Connected to the flow path of Repeat the discharge, the oxidation reactor 21, a predetermined amount of sample water, dilution water, potassium peroxodisulfate may be sequentially supplied to NaOH. In this case, it is necessary to connect the syringe pump 16 to the flow path of the dilution water and wash the inside of the flow path leading to the syringe pump 16 and the oxidation reactor 21 before collecting sample water and the like sequentially with the syringe pump 16. There is.

d) The sample water after the oxidation reaction is sucked and collected by the syringe pump 16 and then the distribution port A2 connected to hydrochloric acid in the first multiport valve A is connected to the common port A1, A predetermined amount of hydrochloric acid is added to the sample water after the oxidation reaction to adjust to a predetermined ph value, and gas is supplied into the syringe pump 16 by the same method as in the above c) and stirred by bubbling to be uniformized. The

e) The distribution port A2 connected to the communication pipe 19 in the first multiport valve A is connected to the common port A1, and the distribution port B2 connected to the measurement cell 23a in the second multiport valve B is connected to the communication pipe 19 in common. Connected to the port A1, the ph-adjusted sample water in the syringe pump 16 is sent to the measurement cell 23a of the absorbance measurement unit 23, and the absorbance of the nitrate ion having a wavelength of 220 nm is measured by the absorbance measurement unit 23. The absorbance of ions is calculated by the control / data processing unit 24 to obtain the TN concentration and displayed on the display unit 25. The aqueous solution sample overflowed from the measurement cell 23a is discarded.

f) The sample water after the measurement is sucked by the syringe pump 16, and then the distribution port B2 connected to the drain port in the second multiport valve B is connected to the common port B1, and the measurement in the syringe pump 16 is performed. The finished sample water is drained out of the apparatus through the drain port.

(B) TP measurement a) Under the control of the control / data processing unit 14, one of the distribution ports B2 connected to the flow path of the sample 1 or the sample 2 in the second multiport valve B is connected to the common port B1, In addition, the distribution port A2 to which the communication pipe 10 is connected in the first multiport valve A is connected to the common port A1 to which the syringe pump 16 is connected, and only a necessary amount of sample water to be measured is contained in the syringe pump body 16. After aspiration sampling, if a predetermined dilution rate is set, the second multiport valve B is connected to the distribution port B2 common port B1 connected to the flow path of the dilution water and sucked into the syringe pump 16 A predetermined amount of dilution water is added to the sample water.

b) In the first multiport valve A, a distribution port A2 connected to the flow path of the potassium peroxodisulfate solution and nitric acid is sequentially connected to the common port A1, and a predetermined amount of peroxo is added to the diluted sample water in the syringe pump 16. Potassium disulfate and nitric acid are added.

c) After connecting the distribution port A2 connected to the atmosphere to the common port A1 in the first multi-port valve A, the stirring pump is driven to supply gas into the syringe pump 16, and the solution in the pump is bubbled. After stirring, the distribution port A2 connected to the communication pipe 19 in the first multiport valve A is connected to the common port A1, and the distribution port B2 connected to the oxidation reactor 21 is connected in the second multiport valve B. Connected to the common port B1, the sample water added with potassium peroxosulfate and nitric acid in the syringe pump 16 homogenized by stirring is sent to the oxidation reaction part 21 and irradiated with ultraviolet rays for a predetermined time or heated. The phosphorus compound in the sample water is decomposed into phosphate ions.

d) Distribution port A2 connected to the flow path of NaOH, ammonium molybdate solution, and L-ascorbic acid solution in the first multiport valve A after a predetermined amount of sample water having been subjected to the oxidation reaction is sucked and collected by the syringe pump 16 Are sequentially connected to the common port A1, and a predetermined amount of NaOH, ammonium molybdate solution, and L-ascorbic acid solution are added to the sample water in the syringe pump 16, and the same procedure as in c) above is applied to the syringe pump 16. Gas is supplied and agitated by bubbling, homogenization is performed, and a coloring reaction is caused in the syringe pump 16.

e) The distribution port A2 connected to the communication pipe 19 in the first multiport valve A is connected to the common port A1, and the distribution port B2 connected to the measurement cell 23a in the second multiport valve B is connected to the communication pipe 19 in common. The sample water connected to the port B1 and having undergone the color reaction was sent to the measuring cell 23a of the absorbance measuring unit 23 by the syringe pump 16, and the absorbance of the phosphate ion having a wavelength of 880 nm was measured and measured by the absorbance measuring unit 23. The absorbance of phosphate ions is calculated by the control / data processing unit 24 to obtain the TP concentration and displayed on the display unit 25.

f) The sample water after measurement is sucked by the syringe pump 16, and then the distribution port B2 connected to the drain port in the second multi-port valve B is connected to the common port B1, and the sample water in the syringe pump 18 is And discharged from the drain port.

In the examples, the aqueous solution metering / liquid feeding mechanism according to the present invention is applied to the sample injector in the TN / TP meter, but it can also be applied to a TN meter and a TP meter that analyze only TN and TP. . In addition, the oxidative decomposition of the sample water to which the oxidizing agent is added may be by high-temperature heating, but if it is oxidatively decomposed by irradiating with ultraviolet rays, high-temperature heating is not required, and oxidation reaction (decomposition ) Part configuration and operation become simple. Furthermore, in the embodiment, the flow path connected to each reagent is connected to the distribution port of the multi-port valve where the syringe pump is connected to the common port, but the flow path connected to the reagent may be connected to the other distribution port. However, if the reagent flow path is connected to the distribution port of the multi-port valve to which the syringe pump is connected as in the embodiment, the flow path from the reagent container to the syringe pump can be shortened and the consumption of reagent can be reduced. Can be planned.

Further, in the TN / TP meter of the example, the oxidatively decomposed sample water and the color former are sucked into a syringe-type metering pump (syringe pump), and a color reaction is performed in the syringe pump. The absorbance was measured by transferring water to the measurement cell of the absorbance measurement unit. However, a color former was added to the oxidatively decomposed sample water in the oxidation reactor, and the sample water after the color reaction was sucked with a syringe pump. Then, the absorbance may be measured by transferring the sample to the measurement cell of the absorbance measurement unit. Alternatively, a coloring agent may be added to the oxidized sample water in the transferred sample cell to cause a color reaction in the measurement cell. The absorbance of the sample water after the color development reaction may be measured. If a color former is added to the sample water in the oxidation reactor and the color reaction is carried out in the oxidation reaction part, the color reaction can be performed during the TP measurement, and the analysis efficiency of TP and TN can be improved. There is an advantage that can be.

It is a figure which shows schematic structure of one Example which applied this invention to the water quality | type analyzer. It is a figure which shows schematic structure of the other Example which applied this invention to the water quality | type analyzer.

Explanation of symbols

2: TC oxidation reaction part 3: TC combustion tube
15: Sample injector A: 1st and 2nd multi-port valve (A1 common port, A2 distribution port)
B ... Second multiport valve (B1 common port, B2 distribution port)
16 ... Syringe type metering pump (17 ... Syringe body, 18 ... Plunger, 19 ... Communication pipe)
21: Oxidation reactor 23: Absorbance measurement unit (23a ... measurement cell)

Claims (11)

At least two multi-port valves having one common port and a plurality of distribution ports, a motor connected to each multi-port valve and switching the connection relationship between the common port and the distribution port, and the motors synchronized with each other And a syringe-type metering pump for measuring / collecting and feeding an aqueous solution to a common port of one multiport valve, and one of the distribution ports of the multiport valve to which the pump is connected. The port is connected to the common port of the other multi-port valve, and the other distribution ports of the two correspond to each port, and each flow path required for analysis including the aqueous solution sample flow path and reagent flow path Are connected to each other and the common port of one multi-port valve to which the syringe metering pump is connected via the corresponding distribution port. Weighing-sending mechanism of the analysis solution, characterized in that it is connectable to and. 2. The analytical aqueous solution metering / liquid feeding mechanism according to claim 1, wherein the syringe-type metering pump has a gas introduction channel, and the introduction channel is connected to a gas supply source. A measuring and feeding mechanism for aqueous solution for analysis. A water quality analyzer comprising a sample injector for collecting an aqueous solution sample and a measuring unit for measuring a pollutant component in the aqueous solution sample, the sample injector having one common port and a plurality of distribution ports At least two multi-port valves, a motor connected to each multi-port valve, for switching the connection relationship between the common port and the distribution port, and a CPU for synchronously controlling the motors, one multi-port valve A syringe-type metering pump that measures, collects, and delivers an aqueous solution is connected to the common port of the multiport valve, and one port of the distribution port of the multiport valve connected to the pump is connected to the common port of the other multiport valve. In addition, each of the other distribution ports is connected to each flow path required for analysis, including the aqueous solution sample flow path and reagent flow path, corresponding to each port. Water analysis apparatus characterized by being. A reaction part including at least a total carbon oxidation reaction part for converting all carbon in the aqueous solution sample into carbon dioxide; a sample injector for collecting a certain amount of the aqueous solution sample and injecting the same into the reaction part; and a carrier gas in the reaction part A water quality analyzer comprising a carrier gas supply unit for supplying carbon dioxide and a carbon dioxide detection unit for detecting carbon dioxide sent together with the carrier gas from the reaction unit, wherein the sample injector is shared by one At least two multi-port valves having a port and a plurality of distribution ports; a motor connected to each multi-port valve for switching the connection relationship between the common port and the distribution port; and a CPU for synchronously controlling the motors; And a syringe-type metering pump for measuring, collecting and feeding the aqueous solution is connected to the common port of one multi-port valve. One of the distribution ports of the multiport valve is connected to the common port of the other multiport valve, and the other distribution port of the multiport valve is connected to the reaction unit, the aqueous solution sample, corresponding to each port. A water quality analyzer characterized in that several channels including a supply channel and a washing water supply channel are connected. 5. The water quality analyzer according to claim 4, wherein the syringe-type metering pump has a gas introduction channel, and the introduction channel is connected to a gas supply source. . An oxidation reaction (decomposition) unit that oxidizes an aqueous solution sample to which an oxidant has been added, a measurement unit that measures an analyte in an oxidatively decomposed aqueous solution sample, and an aqueous solution sample are weighed and sent to the oxidation reaction unit. And a sample injector that measures and collects the aqueous solution sample oxidized and decomposed in the oxidation reaction unit and sends the sample to the measurement unit, wherein the sample injector has one common port. And at least two multi-port valves having a plurality of distribution ports, a motor connected to each multi-port valve, for switching the connection relationship between the common port and the distribution port, and a CPU for synchronously controlling the motors. A syringe-type metering pump for measuring / collecting and feeding an aqueous solution is connected to the common port of one multiport valve, and the distribution port of the multiport valve to which the pump is connected is connected. One port is connected to the common port of the other multi-port valve, and the other distribution port of each of them is an aqueous solution sample, the oxidation reaction unit, a measurement unit, and an aqueous solution sample corresponding to each port. A water quality analyzing apparatus characterized in that several flow paths including a flow path for an oxidant added to the water are connected. 7. The water quality analyzer according to claim 6, wherein the syringe-type metering pump has a gas introduction channel, and the introduction channel is connected to a gas supply source. . 8. The water quality analyzer according to claim 6, wherein the oxidation reaction part oxidizes and decomposes the aqueous solution sample to which the oxidant is added by irradiating with ultraviolet rays. Water quality analyzer. The water quality analyzer according to any one of claims 6 to 8, wherein the measuring unit measures an analysis target component in the aqueous solution sample by measuring the absorbance of the aqueous solution sample. Water quality analyzer. The water quality analyzer according to any one of claims 6 to 9, wherein the water quality analyzer measures total nitrogen. 10. The water quality analyzer according to claim 6, wherein the water quality analyzer measures total phosphorus in which a flow path connected to a color former is connected to a distribution port of the multi-port valve. A characteristic water quality analyzer.

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