JPH11241997A - Measuring device ion concentration in water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inject different reaction reagents to the form of an ion to be measured to a sample solution without being mutually mixed in switching of measurement mode, and to enhance the responsiveness to improve the measuring precision and efficiency. SOLUTION: This device has, an 'ammonia measuring pretreatment device unit 20', a 'nitrous acid measuring pretreatment device unit 30', and a 'nitric acid measuring pretreatment device unit each separately formed, having' as essential components, a sample solution injection port 1 to a passage capillary 2 in which a sample solution flows, a reagent solution injection port 3, a clean air injection port 5, a mixer 6, an evaporating separator 7 and each driving pump. The connection of either one of the units with a detector 10 is switched by a selector valve 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates is a 3 nitrogen contained in the water, such as tap water Toka sewage ammonium ion (NH ₄ ^+), nitrite (NO ₂ ^-), nitrate ion (N
The present invention relates to an ion concentration measurement device for measuring the concentration of O ₃ ⁻ ) in a short time with high sensitivity using the principle of flow injection analysis and chemiluminescence.

[0002]

2. Description of the Related Art In general, ion chromatography, colorimetry, neutralization titration, and ion electrode method have been used as methods for measuring and analyzing the above-mentioned tri-state nitrogen present in water of rivers and lakes to a low concentration. Have been.

[0003] Among them, ion chromatography, which is classified as instrumental analysis, is a type of high-performance liquid chromatography using an ion exchange column and has been developed for systematic analysis of inorganic anions and cations. Te, made the difficulties in analyzing the conventional ^{F -, Cl -, Br -} , NO 2 -, N
Inorganic anions such as O ₃ ⁻ , SO ₃ ²⁻ , SO ₄ ²⁻ , and PO ₄ ³⁻ can be quantified. In the analysis, when a sample solution is injected into the upper end of a separation column filled with anion exchange resin particles, anions are adsorbed to the column by ionic bonds. Next, when an eluent containing a competing anion that is hardly detected is passed through the conductivity detector, each anion competes with the competing ion and elutes from the column with a specific mobility. Can be determined.

[0004] In the ion chromatography method, the ammonium ion is converted from several ppm to several tens pp using a conductivity detector.
The measurement can be performed up to the m-level concentration, and the measurement time requires several minutes to about 10 minutes after the introduction of the sample. The quantification range is a relatively high concentration of 0.1 to 30 (mg / l).

[0005] In the case of this ion chromatograph method, the quantitative range can be relatively low, but the measurement time excluding the pretreatment and the time for preparing the calibration curve requires a considerably long time of several minutes to 10 minutes. The presence of a suspended substance (such as a turbid component in water) or an organic component in the test water interferes with the measurement, and thus requires pretreatment using a prefilter or the like. In addition, continuous measurement of river water, lake marsh water, sewage treatment water, and the like except tap water is difficult due to insufficient response to dirt.

[0006] A method of simultaneously measuring cations and anions by switching the flow channel by mounting an ion exchange column for cations and anions can be considered. However, since there are many movable parts, it is likely to cause a failure. It is difficult to measure ions and anions simultaneously. In addition, the degree of deterioration of the ion exchange column is large due to the contamination of the water sample described above,
There is also a problem that maintenance such as replacement of the pre-filter is required because the measurement accuracy may be reduced.

[0007] The colorimetric method is based on indophenol blue absorption in which the concentration of ammonium ion is determined by measuring the absorbance at 630 nm of indophenol blue produced by the reaction of ammonium ion with phenol in the presence of hypochlorite ion. The photometric method is a representative method, and the quantification range is 1.6 to 33.
(Mg / l), which is relatively high.

This colorimetric method is a method of continuously measuring ammonium ions by introducing a reagent into a test water as a sample and measuring absorbance at a specific wavelength from a chemical reaction formula equivalent to the substance to be measured. Pretreatment, color development, absorbance measurement and many manual analysis operations are required.
Since a large amount of about 0 ml is required, and the measurement time is 30 minutes to 1 hour or more in all steps, automation of the measurement device is difficult at present. In particular, since the measurement principle is based on colorimetry, measurement at the ppm level is possible.
In the case of measurement at the level, there is a problem that practical use is difficult due to a large measurement error.

In the neutralization titration method, ammonia extracted by performing a pretreatment by distillation is converted into a fixed amount of sulfuric acid (25 mmol / l).
This is a method for titrating ammonium ion by quantifying the solution absorbed therein with a 50 (mmol / l) sodium hydroxide solution, and the quantification range is from 0.3 to 40 (mg / l).
l) and relatively high concentration.

In the ion electrode method, a sodium hydroxide solution is added to a pretreated sample to adjust the pH to 11 to 13 to change ammonium ions to ammonia, and the potential is measured using an indicator electrode (ammonia electrode). Method for quantifying ammonium ions by using a quantification range of 0.1 to 100.
(Mg / l), which is quite high.

The neutralization titration method and the anion electrode method are both complicated in operation, require a long time for measurement, and have a considerably high quantitative range. As a problem before considering the automation of the measuring device, there is a problem that the measurement accuracy does not satisfy the condition.

[0012] On the other hand, a measurement device using a flow injection analysis method and a chemiluminescence method has been studied. This method has a very high response speed, can greatly reduce the measurement time, and has a large linearity range of a calibration curve. For this reason, it has attracted attention because of its wide measurement range.

Referring to FIG. 5, the principle of measurement by the flow injection analysis method and the chemiluminescence method will be described. First, a sample solution containing ammonium ions, nitrite ions, and nitrate ions is injected from the sample solution inlet 1 and a constant flow pump P ₂
Of while flowing down the flow path capillary in 2 by the drive, the reagent solution inlet 3a, 3b, each liquid injection pump multiple reagent from 3c P _3, P _4, the flow path of the drive and the injection port 4 P ₅ By switching, it is selectively injected into the flow channel thin tube 2.

When the clean air injected from the clean air inlet 5 by driving the air pump P ₁ is introduced into the flow channel thin tube 2 at the point C, the sample solution and the reaction reagent are sufficiently mixed in the mixer 6. The reaction is accelerated, and the gas dissolved in the liquid phase of the reaction solution is separated into the gas phase and enters the vaporizer 7. Clean air is injected into the vaporizer 7 from a clean air inlet 5a.

The gas component separated by the vaporizer 7 is converted into nitrogen monoxide (NO) by entering the heating oxidizing furnace 8 and heated, and the liquid component is driven from the vaporizer 7 by the waste liquid pump P ₆ . Is discharged as waste liquid 7a.

The gas component of the thermal oxidation furnace 8, is sucked into the chemiluminescence detector 10 is depressurized by driving the exhaust pump P ₇ after being dried in a dryer 9. This chemiluminescence detector 1
0, ozone gas obtained by the ozone generator 11 is introduced, and nitrogen monoxide (NO) and ozone gas O
_The chemiluminescence at the time of generating NO ₂ gas by the reaction ₃ is detected by the chemiluminescence detector 10, a detection signal is input to the arithmetic and control unit 12, and the tristate nitrogen is determined from the relationship between the injected reagent and the chemiluminescence intensity Display and recording unit 1
3 is recorded and displayed.

The arithmetic and control unit 12 controls the driving of the pumps P _{1 to} P ₇ , the switching state of the injection port 4, the temperature control of the heating oxidizing furnace 8, and the switching of the operation / stop of the ozone generator 11. Control signals 12a and 12b to be controlled are output. Also, the exhaust pump P ₇ is a chemiluminescence detector 1
It has both the function of reducing the pressure within 0 and the function of extracting the gas components after measurement.

As a reaction reagent to be used, hypochlorous acid (HOCl) or sodium hypochlorite (NaClO) is used for measurement of ammonium ion. Further, potassium iodide (KI) is used for measuring nitrite ions, and titanium trichloride (TiCl ₃ ) is used for measuring nitrate ions.

When a titanium trichloride solution is used as a reaction reagent, the reaction target is involved not only in nitric acid but also in nitrous acid, and therefore corresponds to the nitrous acid concentration measured in the "nitrite measuring mode". A correction must be made to subtract the output from the "computed waveform" output from the titanium trichloride solution. Thereafter, the concentration calculation operation is performed in the same manner as the other measurement items, and the nitric acid concentration is output.

FIG. 6 is a flow chart showing a procedure for measuring tri-state nitrogen by the flow injection analysis method and the chemiluminescence method. As shown in FIG. 6, the measurement modes are "ammonia measurement", "nitrite measurement", and "nitrogen measurement". The procedure of “Measurement of nitric acid” is repeated.

More specifically, the reagent injection operation is performed at the seven times indicated by □ in FIG. 6 for the “sodium hypochlorite solution”, “potassium iodide solution”, and “titanium trichloride solution”. This is performed by a method of injecting the reagent in a pulsed manner. The number of detector measurement waveforms is seven in accordance with the timing, but only three waveforms are used in the latter stage. In the concentration calculation operation, the ammonia concentration is determined from the above-mentioned calculated waveform output using a calibration curve (prepared from the ammonia concentration using the standard solution and the detector output), and the nitrite concentration and the nitric acid concentration are similarly determined in the order of the calibration curve method. Ask.

[0022] is also used as a detector of the NO _X meter for measuring nitrogen oxides is a chemiluminescent detector. Chemiluminescence is a phenomenon in which light is emitted when a molecule is excited by a chemical reaction and returns to a ground state, and qualitative analysis can be performed by analyzing the emission spectrum, and quantitative analysis can be performed by measuring the amount of light. The chemiluminescence detector of this example is a method that utilizes chemiluminescence when nitric oxide (NO) gas reacts with ozone gas (O ₃ ) gas to generate nitrogen dioxide (NO ₂ ) gas. Since the emission intensity is proportional to the concentration of nitric oxide, the NO intensity can be measured by measuring the emission intensity with a photomultiplier tube. NO + O ₃ → NO ₂ + O ₂ + hν (light) (1) 590 to 2500 n which is the wavelength region of chemiluminescence of this reaction
Among m, light of 610 to 875 nm is measured from the photocathode characteristics of the photomultiplier tube and the characteristics of the short wavelength cut filter used.

[0023]

Among the above-mentioned methods for measuring the ion concentration in water, the flow injection analysis method involves continuously injecting a reaction reagent into a sample solution at a constant flow rate flowing continuously through a thin tube, and While automatically controlling the mixing of the sample solution and the reaction reagent in the flow in the thin tube in a flowing state, the chemical reaction is performed precisely and rationally, and the obtained reaction product is detected by various detectors. This is an analysis method for detecting and quantifying, and the time between injection of a reaction reagent into a sample solution and detection of a reaction product can be kept constant from the relationship between the volume of a Teflon tube used and the flow rate of a pump. Therefore, it is possible to strictly control the reaction process, and even if it is detected in the middle of the reaction, the detection accuracy and the reproducibility are excellent, and the three-state nitrogen can be measured quickly and in a closed system. It is characterized by the fact that it is difficult for individual differences to intervene because the chemical reaction is used.

As conditions for continuously measuring ammonium ion concentration, nitrite ion concentration and nitrate ion concentration by the flow injection analysis method, when a reaction reagent corresponding to the form of nitrogen to be measured is injected. It is necessary to employ a technical means for injecting the reaction reagents into the sample solution in a pulse form without mixing with each other.

However, when the apparatus shown in FIG. 5 is used, a plurality of reaction reagents flowing from the reagent solution inlets 3a, 3b, 3c by switching the flow path of the injection port 4 are supplied to the chemical solution injection pumps P ₃ , P ₄ , P _5. , The reaction reagents are selectively injected into the flow channel thin tube 2, so that there is a disadvantage that the reaction reagents are mixed with each other for a period of time when the flow path of the injection port 4 is switched.

Therefore, as described with reference to FIG. 6, the reaction reagent is injected in a pulsed manner at a predetermined timing, and the "operation adopted waveform" is selected from the detector measurement waveforms and the operation control unit 12 is selected.
And the calibration curve is used to obtain “ammonia concentration”, “nitrite concentration”, and “nitric acid concentration” in this order. However, when the flow path of the injection port 4 is switched due to the change of the measurement mode, the reagent used in the previous measurement mode is used. And the reagent used in the current measurement mode are mixed, and the waveform is likely to be unstable several times before the influence of the reagent in the previous measurement mode disappears.

For this reason, a plurality of reagent injection operations are required for each measurement mode, so that the amount of reagent required for one measurement increases and the measurement time increases.

Therefore, the present invention solves the problem of the conventional ion concentration measuring apparatus and mixes different reaction reagents with each other in the form of ions to be measured when the measurement mode is switched. To provide an ion concentration measuring apparatus in water which can be injected into a sample solution without performing the method, does not require a complicated manual analysis operation, and can improve the response and improve the measurement accuracy and efficiency. It is intended for.

[0029]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method in which a sample solution containing ammonium ions, nitrate ions and nitrite ions is caused to flow down a flow tube by driving a fluid pump. The reaction reagent is selectively injected and mixed into the sample solution from a plurality of reagent solution inlets, and a gas component separated from a liquid phase by a vaporization separator is converted to nitric oxide in a heating oxidation furnace, and then detected by a detector. In a measuring device that detects chemiluminescence intensity and measures ammonium ion, nitrate ion, and nitrite ion concentrations in the gas phase using flow injection analysis and chemiluminescence, a sample solution injection port into a flow channel thin tube is used. "Ammonia measurement pretreatment unit" with the main components of reagent solution inlet, clean air inlet, mixer, vaporizer and drive pump An ion concentration in water in which a "pretreatment device unit for measuring nitrous acid" and a "pretreatment device unit for measuring nitric acid" are separately formed, and the connection state of any one of the above units and the detector is switched by a switching valve. It has the configuration of a measuring device.

Further, the number of “pretreatment unit for ammonia measurement”, “pretreatment unit for nitrite measurement” and “pretreatment unit for nitric acid measurement” may be increased or decreased according to the measurement purpose. . As a reaction reagent to be injected from the reagent solution inlet, hypochlorite or sodium hypochlorite is used when the detected ions are ammonium ions, and potassium iodide is used when the detected ions are nitrite ions. When the ions to be detected are nitrate ions, titanium trichloride is used.

According to such an apparatus for measuring ion concentration in water, the switching valve is operated at the time of measurement, and the "pretreatment unit for measuring ammonia", the "pretreatment unit for measuring nitrous acid", and the "pretreatment unit for measuring nitric acid" are used. One of the "units"
When the connection state between one unit and the detector is switched and the other unit is disconnected from the measurement system, the sample solution injected from the sample solution injection port flows down the flow tube and mixes with the reaction reagent. The gas components separated from the liquid phase by the vaporizer are sent to the heating oxidizing furnace to be converted into nitric oxide, and then the nitric oxide in the gas phase is detected by the detector. And the intensity of the chemiluminescence produced by the reaction between
From this detection result, ammonium ions, nitrite ions or nitrate ions in the gas phase are separately quantified.

In the above operation, when the measurement unit is switched by the switching valve in accordance with the change of the measurement mode,
The reagent used in the previous measurement mode and the reagent used in the current measurement mode are not mixed, and measurement can be performed by injecting the reaction reagent only once in each measurement mode in each measurement mode. And measurement accuracy and efficiency can be improved.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the apparatus for measuring ion concentration in water according to the present invention will be described in detail below by attaching the same reference numerals to the same components as those of the above-mentioned conventional components. FIG. 1 is a schematic diagram of a measuring device for quantifying tri-state nitrogen in water based on a first embodiment of the present invention, wherein 1 is a sample solution inlet, 3 is a reagent solution inlet, and 2 is a flow channel. use tubules, 5 clean air inlet, P ₁ is an air pump, P ₂ is a constant flow pump,
P ₃ is liquid injection pump, 4 is the injection port.

Reference numeral 6 denotes a mixer, 7 denotes a vaporization separator, and the vaporization separator 7 has a clean air inlet 5a and a drain pump P
₆ and an outlet for waste liquid 7a.

In this embodiment, the sample solution inlet 1, the reagent solution inlet 3, the flow tube 2, the clean air inlet 5, the mixer 6, the vaporizer 7, and the pumps P ₁ ,
An “ammonia measurement pretreatment device unit 20” having P ₂ , P ₃ , and P ₆ as main components is formed.

[0036] 8 thermal oxidation furnace, 9 dryer, 10 chemiluminescence detector, P ₇ is an exhaust pump that is attached to the chemiluminescent detector 10, 11 is an ozone generator, 12 is the arithmetic control unit, 1
Reference numeral 3 denotes a display / recording unit.

The mixer 6 aims at smoothly mixing and reacting the sample solution and the reaction reagent by causing a turbulent flow in the coiled Teflon tube. Regarding the length of the coil, it is necessary to experimentally determine the optimum length with good sensitivity.

The reagent solution inlet 3 is connected to the injection port 4 of the flow path capillary 2 through a liquid injection pump P _3.

On the other hand, reference numeral 30 denotes a "pretreatment unit for measuring nitrite", and reference numeral 40 denotes a pretreatment unit for measuring nitric acid. This "pretreatment device unit 3 for nitrous acid measurement"
The basic configuration of “0” and “pretreatment unit 40 for nitric acid measurement” is the same as “pretreatment unit 20 for ammonia measurement” in FIG.

A switching valve 21 is provided between the "ammonia measurement pretreatment device unit 20" and the heating oxidation furnace 8, and the "ammonia measurement pretreatment device unit 20" and the "ammonia measurement pretreatment device unit 20" Pretreatment unit 30 for nitric acid measurement ”and“ Pretreatment unit 4 for nitric acid measurement ”
The flow state between any one unit of “0” and the heating oxidation furnace 8 is switched.

The operation of the first embodiment will be described below. [Ammonia measurement mode] First, the switching valve 21 is operated to bring the "ammonia measurement pretreatment unit 20" and the heating oxidation furnace 8 into a flow state, and the other units 30, 40 are disconnected from the measurement system. Then, the sample solution is injected from the sample solution inlet 1, and is driven down by the constant flow rate pump P ₂ to flow through the narrow tube 2 for the flow of the reagent solution.
The hypochlorous acid as reagent by driving the liquid injector pump P ₃ (HOCl) or sodium hypochlorite (N
aCLO) is once injected in a pulsed manner into the flow channel 2 via the injection port 4.

Next, the clean air injected from the clean air inlet 5 by driving the air pump P ₁ is introduced into the flow channel thin tube 2 at the point C, and is sufficiently introduced into the mixer 6 together with the sample solution and the reaction reagent. The reaction is promoted by mixing, and the gas dissolved in the liquid phase of the reaction solution is separated into the gas phase and enters the vaporizer 7. Clean air is injected into the vaporizer 7 from a clean air inlet 5a.

The gas component separated by the vaporization separator 7 is converted into nitrogen monoxide (NO) by entering the heating oxidation furnace 8 at the next stage and heated, and the liquid component is discharged from the vaporization separator 7 It is discharged as waste 7a by driving the pump P _6.

The gas component of the thermal oxidation furnace 8 is sucked to the chemiluminescence detector 10 is depressurized by driving the exhaust pump P ₇ after being dried in a dryer 9, the chemiluminescence detector 10
The reaction between the ozone gas introduced from the ozone generator 11 and the nitric oxide (NO) in the gas phase generates NO ₂ gas, and the chemiluminescence at this time is detected by the chemiluminescence detector 10 and the detection signal is calculated. It is input to the control unit 12.

From the relationship between the injected reaction reagent and the chemiluminescence intensity, the ammonium ion was quantified using a calibration curve prepared in advance from the ammonia concentration of the standard solution and the output of the detector, and recorded in the display / recording unit 13. Is displayed.

[Nitrite Measurement Mode] The switching valve 21 is operated to put the "nitrite measurement pretreatment unit 30" and the heating and oxidizing furnace 8 in a flowing state, and the other units 20, 40 are disconnected from the measurement system. State. Since the configuration of the “pretreatment device unit 30 for nitrous acid measurement” matches the “pretreatment device unit 20 for ammonia measurement”, the operation will be described with the aid of this unit 20.

While the sample solution is injected from the sample solution inlet 1 and flows down the flow channel ₂ by driving the constant flow rate pump P ₂ , the reaction reagent is driven by driving the chemical solution injection pump P ₃ from the reagent solution inlet 3. Potassium iodide (KI) is injected once into the narrow flow channel 2 via the injection port 4 in a pulsed manner.

Then, the clean air injected from the clean air inlet 5 by driving the air pump P ₁ is introduced into the flow channel thin tube 2 at the point C and flows into the mixer 6. The chemiluminescence is detected by the chemiluminescence detector 10 by the operation, and based on the relationship between the injected reaction reagent and the chemiluminescence intensity, the determination of nitrite ion is performed using a calibration curve prepared in advance from the nitrite concentration with the standard solution and the output of the detector. Is performed and recorded and displayed on the display / recording unit 13.

[Nitric acid measurement mode] By operating the switching valve 21, the "pretreatment unit 40 for nitric acid measurement" and the heating oxidation furnace 8
The space between them is set to a circulation state, and the other units 20 and 30 are separated from the measurement system. The configuration of the “pretreatment device unit for nitric acid measurement 40” is also identical to the “pretreatment device unit for ammonia measurement 20”. A sample solution is injected from the sample solution inlet 1 and a constant flow pump P ₂
The titanium trichloride (TiCl ₃ ) as a reaction reagent is injected through the injection port 4 by driving the chemical solution injection pump P ₃ from the reagent solution inlet 3 while flowing down the inside of the flow channel thin tube 2 by the drive. 2 is pulsed once.

Then, the clean air injected from the clean air inlet 5 by driving the air pump P ₁ is introduced into the flow channel thin tube 2 at the point C and flows into the mixer 6. The chemiluminescence is detected by the chemiluminescence detector 10 by the operation, and from the relationship between the injected reaction reagent and the chemiluminescence intensity, the amount of nitrate ion is determined using a calibration curve prepared in advance from the nitric acid concentration of the standard solution and the output of the detector. Then, it is recorded on the display / recording unit 13 and displayed.

When using titanium trichloride as a reagent, not only nitrate ions but also nitrite ions are involved in the reaction. Therefore, the output component corresponding to the nitrite concentration measured in the [nitrite measurement mode] is used. It is necessary to make a correction to be subtracted from the output of the chemiluminescence detector 10 using titanium trichloride.

The arithmetic and control unit 12 drives the pumps P ₁ , P ₂ , P ₃ , P ₆ , P ₇ and switches the injection port 4, adjusts the temperature of the heating oxidation furnace 8, and operates the ozone generator 11. Control signals 12a and 1 for controlling the switching
2b is output.

In this way, the measurement signal from the chemiluminescence detector 10 is subjected to arithmetic processing by the arithmetic and control unit 12 and converted into nitrogen concentration, and is displayed on the display / recording unit 13 and recorded by a printer or the like. The time can measure the three-state nitrogen. After the end of the nitric acid measurement mode, the process returns to the ammonia measurement mode again, and the three measurement modes are repeated.

Since nitrate ions (NO ₃ ⁻ ) have three O atoms and nitrite ions (NO ₂ ⁻ ) have two O atoms, nitrite ions are more easily reduced to NO. By taking advantage of this difference, potassium iodide (KI) that can reduce only nitrite ion to NO, and titanium trichloride (Ti) that can reduce both nitrite ion and nitrate ion to NO
(Cl ₃ )) is used as a reaction reagent. The respective reaction formulas are as follows.

NO ₃ ⁻ + 3Ti ³⁺ → NO + 3Ti ⁴⁺ (2) 2NO ₂ ⁻ + 2I ⁻ → 2NO + I ₂ (3) FIG. 2 shows the present invention. FIG. 3 is a schematic diagram of an ion concentration measurement device based on the second embodiment. Since the basic configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals.

This embodiment is an example of a measuring apparatus for measuring ammonium ions and nitrate ions in tri-state nitrogen, wherein 1 is a sample solution inlet, 3 is a reagent solution inlet, 2 is a thin tube for a flow path, 4 injection port 5 is clean air inlet, P ₁ is an air pump, P ₂ is a constant flow pump, P ₃ is a liquid injection pump.

Reference numeral 6 denotes a mixer, and 7 denotes a vaporizer. The vaporizer 7 has a clean air inlet 5a and a drain pump P
₆ and an outlet for waste liquid 7a. The above-described sample solution inlet 1, reagent solution inlet 3, flow channel capillary 2, clean air inlet 5, mixer 6, vaporizer 7 and pumps P ₁ , P ₂ , P ₃ and P ₆ are mainly used. An “ammonia measurement pretreatment device unit 20” as a constituent element is formed.

Reference numeral 40 denotes a "pretreatment unit for measuring nitric acid".
The basic configuration of this “pretreatment unit for nitric acid measurement 40” is “a pretreatment unit for ammonia measurement 2”.
0 ". Further, a switching valve 21 is provided between the “ammonia measurement pretreatment device unit 20” and the heating and oxidizing furnace 8, and the switching valve 21 allows the “ammonia measurement pretreatment device unit 20” and the “nitric acid measurement The flow state between any one of the pretreatment device units 40 "and the heating oxidation furnace 8 is switched.

The second embodiment is an example of a measuring apparatus in which the “pretreatment unit for nitrite measurement 30” in the first embodiment is removed. The operation mode is as follows. The flow between any one of the pretreatment device unit 20 and the pretreatment device unit for nitric acid measurement 40 and the heating and oxidizing furnace 8 is set to the same state as the above-described [ammonia measurement mode] or [nitric acid measurement mode]. (Detailed description is omitted because it is the same as the above example).

FIG. 3 is a schematic view of a measuring device according to a third embodiment of the present invention. In this example, an example of a measuring device for measuring ammonium ions and nitrite ions in tri-state nitrogen is shown. 1 is a sample solution inlet, 3 is a reagent solution inlet,
2 the flow path tubules, 4 injection port, 5 clean air inlet, P ₁ is an air pump, P ₂ is a constant flow pump, P ₃ is a liquid injection pump.

Reference numeral 6 denotes a mixer, and 7 denotes a vaporizer. The vaporizer 7 has a clean air inlet 5a and a drain pump P
₆ and an outlet for waste liquid 7a. The above-described sample solution inlet 1, reagent solution inlet 3, flow channel capillary 2, clean air inlet 5, mixer 6, vaporizer 7 and pumps P ₁ , P ₂ , P ₃ and P ₆ are mainly used. An “ammonia measurement pretreatment device unit 20” as a constituent element is formed.

Reference numeral 30 denotes a "pretreatment device unit for measuring nitrous acid".
The basic configuration of “0” matches the “ammonia measurement pretreatment unit 20”. Further, a switching valve 21 is provided between the “ammonia measurement pretreatment device unit 20” and the heating oxidation furnace 8, and the “ammonia measurement pretreatment device unit 20” and the “nitrite measurement The flow state between any one unit of the use pretreatment unit 30 and the heating oxidation furnace 8 is switched.

The third embodiment is a measuring apparatus in which the “nitric acid measurement pre-processing device unit 40” in the first embodiment is removed. The operation mode is as follows. Unit 20 ”or“ Pretreatment device unit 30 for nitrous acid measurement ”is placed in a flow state between the heating oxidation furnace 8 and the same as the above-described [ammonia measurement mode] or [nitrite measurement mode]. The operation is performed (detailed description is omitted because it is the same as the above example).

FIG. 4 is a schematic view of a fourth embodiment of the present invention. In this example, an example of a measuring device for measuring nitrate ions and nitrite ions in tri-state nitrogen is shown. inlet, 3 reagent solution inlet 2 flow path capillary, the injection port 4, 5 clean air inlet, P ₁ is an air pump, P ₂ is a constant flow pump, P ₃ is a liquid injection pump.

Reference numeral 6 denotes a mixer, 7 denotes a vaporization separator, and the vaporization separator 7 has a clean air inlet 5a and a drain pump P
₆ and an outlet for waste liquid 7a. The above-described sample solution inlet 1, reagent solution inlet 3, flow channel capillary 2, clean air inlet 5, mixer 6, vaporizer 7 and pumps P ₁ , P ₂ , P ₃ and P ₆ are mainly used. A “pretreatment device unit for nitric acid measurement 40” as a constituent element is formed.

Reference numeral 30 denotes a "pretreatment device unit for measuring nitrous acid".
The basic configuration of “0” is “pretreatment unit 4 for nitric acid measurement.
0 ". Further, a switching valve 21 is provided between the “pretreatment unit for nitric acid measurement 40” and the heating and oxidizing furnace 8. The flow state between any one unit of the use pretreatment unit 30 and the heating oxidation furnace 8 is switched.

The fourth embodiment is a measuring device in which the “ammonia measurement pretreatment device unit 20” in the first embodiment is removed. The operation mode is as follows. Unit 40 ”or“ nitrite measurement pretreatment device unit 30 ”is placed in a flow state between the heating oxidation furnace 8 and the same unit as the above-described [nitric acid measurement mode] or [nitrite measurement mode]. The operation is performed (detailed description is omitted because it is the same as the above example).

[0068]

As described in detail above, according to the apparatus for measuring ion concentration in water according to the present invention, the "pretreatment unit for ammonia measurement",
Since the connection state between one of the “pretreatment unit for nitrous acid measurement” and “pretreatment unit for nitric acid measurement” and the detector was switched and the other unit was disconnected from the measurement system, the measurement was performed. When the mode is changed, the reaction reagents are not temporarily mixed or the reagent used in the previous measurement mode is not mixed with the reagent used in the current measurement mode. Nitrogen can be measured only by injecting a number of times, and the ion concentration can be continuously measured with a small amount of reaction reagent.

Further, depending on the purpose of measurement, all of the above units may not always be necessary. At that time, it is not necessary to equip unnecessary units, and by increasing or decreasing the number of units, the simplification of the apparatus and the measurement items can be reduced. An increase or decrease can be easily dealt with.

The reaction by the flow injection analysis method has an extremely fast response, so that the measurement time can be greatly reduced. In addition, since the linearity of the calibration curve is large, the measurement range is extremely wide from low concentration to high concentration. The effect of high accuracy and high reproducibility is obtained, and the effect of reducing the amount of reagent used and enabling automatic measurement is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for measuring ion concentration in water based on a first embodiment of the present invention.

FIG. 2 is a schematic diagram of an ion concentration measurement device according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of an ion concentration measurement device according to a third embodiment of the present invention.

FIG. 4 is a schematic diagram of an ion concentration measurement device according to a fourth embodiment of the present invention.

FIG. 5 is a schematic diagram for explaining a measurement principle by a flow injection analysis method and a chemiluminescence method.

FIG. 6 is a flow chart for measuring trimorphic nitrogen by a flow injection analysis method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sample solution inlet 2 ... Flow channel thin tube 3 ... Reagent solution inlet 4 ... Injection port 5, 5a ... Clean air inlet 6 ... Mixer 7 ... Vaporization separator 8 ... Heated oxidation furnace 9 ... Dryer 10 ... Chemiluminescence detector 11 ... Ozone generator 12 ... Calculation / control unit 13 ... Display / recording unit 20 ... Pretreatment device unit for ammonia measurement 21 ... Switching valve 30 ... Pretreatment device unit for nitrite measurement 40 ... Before nitric acid measurement Processing unit

Claims (3)

[Claims] 1. A reaction solution is introduced into a sample solution from a plurality of reagent solution inlets while a sample solution containing ammonium ions, nitrate ions and nitrite ions is caused to flow down a flow tube by driving a fluid pump. After selectively injecting and mixing and converting the gas component separated from the liquid phase by a vaporizer into nitric oxide in a heating oxidation furnace, the chemiluminescence intensity is detected by a detector, and ammonium ions and nitrate ions in the gas phase are detected. And nitrite ion concentration using a flow injection analysis method and a chemiluminescence method, an ion concentration measurement device, a sample solution injection port and a reagent solution injection port, a clean air injection port, a mixer, and a vaporizer into a flow channel capillary. "Pretreatment unit for measuring ammonia", "Pretreatment unit for measuring nitrous acid", whose main components are a separator and a driving pump, and The pre-processor unit "for nitrate measurements separately formed, and the one of the unit by the switching valve detector of an ion concentration measuring device in water, characterized in that switching the connection state. 2. The number of units of “ammonia measurement pretreatment device unit”, “nitrite measurement pretreatment device unit” and “nitric acid measurement pretreatment device unit” is increased or decreased according to the measurement purpose. The apparatus for measuring ion concentration in water according to claim 1. 3. The reaction reagent to be injected from the reagent solution injection port is hypochlorous acid or sodium hypochlorite when the ion to be detected is ammonium ion, and when the ion to be detected is nitrite ion. 3. The ion concentration measuring apparatus according to claim 1, wherein potassium iodide is titanium trichloride when the ion to be detected is nitrate ion.