KR20020058937A - Compositions of ion selective membrane, manufacturing and total nitrogen analyzer - Google Patents

Abstract

PURPOSE: Provided are a composition of ion selective membrane, and manufacturing method of ion selective membrane and total nitrogen analyzer by using the same, thereby analyzing total nitrogen rapidly, accurately, and cost effectively. CONSTITUTION: The composition of ion selective membrane is manufactured by mixing 66wt.% of PVC(poly vinyl chloride), 2 wt.% of Nonactin and 132 wt.% of DOA(Bis(2-ethylhexyl)adipate). The ion selective membrane is manufactured by the steps of: preparing the composition of ion selective membrane; dissolving the composition into THF(tetrahydrofuran) 1mL; injecting the dissolved composition into a glass tube having a predetermined diameter to evaporate THF solvent and shaping it into a predetermined shape; and cutting the shaping into a predetermined depth.

Description

Preparation method of ion selective sensitized membrane using ion selective sensitized composition, ion selective sensitized composition, and total nitrogen measuring apparatus using ion selective sensitized membrane {Compositions of ion selective membrane, manufacturing and total nitrogen analyzer}

The present invention relates to an ion selective sensitized composition, a method for preparing an ion selective sensitized membrane using the composition, and a total nitrogen measuring apparatus using an ion selective sensitized membrane, and more particularly, to a solution containing various ionic species, The present invention relates to a total nitrogen measuring apparatus for quantifying a target ion by using a potential difference generated between a working electrode and an external reference electrode using bicor glass after converting it into a form.

Recently, with the increase of population, urban expansion and industrial development, inorganic nutrients are increasing in rivers and lakes due to the influx of environmental pollutants such as living sewage and factory wastewater. These inorganic nutrients cause overgrowth of algae, a phenomenon known as eutrophication, which eventually destroys aquatic ecosystems and has a great negative effect on human life.

Therefore, the concentration of nitrogen species present in rivers and lakes is managed and regulated, and the need for equipment to measure the total amount of nitrogen quickly and accurately is very large.

On the other hand, two methods are mainly used for the measurement of total nitrogen, one of which is to decompose the nitrogen compound in the sample with organic matter at 120 ℃ in the presence of alkaline potassium permanganate and oxidize it to nitrate ion, It is a method of quantifying nitrogen species by measuring absorbance.

As described above, the total nitrogen measurement method has a disadvantage in that it should be applied to a sample containing organic matter that is easy to decompose or does not contain bromine ions or chromium, which show absorbance in the ultraviolet portion.

Another method of measuring total nitrogen is to convert all nitrogen species into ammonia gas through a reaction called kjeldahl reaction and then collect and titrate. This method is very classic and has been used for a long time for protein analysis, but it is not suitable for the user who wants to know the concentration of nitrite ion, nitrate ion and ammonium ion because it is calculated as the total amount of nitrogen species.

The present invention has been made to solve the problems of the prior art as described above, after converting a solution containing a variety of ionic species and organic substances into a form that can be measured as an ion-selective electrode through a suitable process, and then operating electrode Ion Selective Sensitive Compositions and Ion Selective Sensitive Compositions Using Ion Selective Sensitive Compositions and Ion Selective Sensitive Compositions to Determine Total Nitrogen Faster and More Accurately by Using Potential Difference Between External Reference Electrodes Using Bicor Glass It is an object of the present invention to provide a method for preparing a membrane and an apparatus for measuring total nitrogen using an ion selective membrane.

1 is a flow chart showing a total nitrogen measurement method applying the Kjeldahl reaction according to the present invention.

2 is a structure of a working electrode to be introduced into a flow cell according to the present invention.

3 is a structure of a reference electrode to be introduced into a flow cell according to the present invention.

4 is a structure of a flow cell in which a working electrode and a reference electrode are disposed in accordance with the present invention.

5 is a sensitivity curve of an ammonium ion selective electrode according to the present invention.

6 is a sensitivity curve of the nitrite ion selective electrode according to the present invention.

FIG. 7 is a sensitivity curve under wall-jet of an ammonium ion selective electrode according to the present invention. FIG.

8 is a sensitivity curve under wall-jet of a nitrite ion selective electrode according to the present invention.

** Description of the main parts of the drawing **

100. Flow cell body 102. Upper cell body

104. Lower cell body 106a, 106b, 106c. Electrode Mount

110. Euro 110a, 110b. Inlet, outlet

120. PVC film layers 130, 130a. Ion selective induction membrane

140, 140a. Packing for fixing sensitized membrane 145, 145a. Internal standard solution

150, 150a. Internal reference electrode 160. Vycor glass

165. Internal reference solution 170. Internal reference electrode

180a, 180b, 180c. Lid 190, 190a. O-ring

The present invention configured to achieve the above object is as follows. That is, the ammonium ion selective sensitive composition according to the present invention is prepared by mixing at a weight ratio of 66 wt% of PVC (poly vinyl chloride), 2 wt% of Nonactin, and 132 wt% of DOA {Bis (2-ethylhexyl) adipate}.

On the other hand, the ammonium ion selective sensitized membrane using the above-described ammonium ion selective sensitizing composition is mixed with a weight ratio of 66 wt% of PVC (poly vinyl chloride), 2 wt% of Nonactin, 132 wt% of DOA {Bis (2-ethylhexyl) adipate} Obtaining an ion selective sensitizing composition; Dissolving the ammonium ion selective sensitive composition in 1 ml of solvent tetrahydrofurane (THF); Pouring ammonium ion selective sensitive composition dissolved in 1 ml of solvent THF (tetrahydrofurane) into a glass tube of a predetermined diameter placed on a glass plate to evaporate the solvent THF into a predetermined shape; And cutting the molding to a predetermined thickness to produce an ammonium ion selective sensitive film.

The nitrite ion selective sensitive composition according to the present invention is prepared by mixing in a weight ratio of PVC 66wt%, Dicyanocobyrinic acid heptapropyl ester 2wt%, DOA {Bis (2-ethylhexyl) adipate} 132wt%.

The nitrite ion selective sensitized membrane using the above-mentioned nitrite ion selective sensitization composition is mixed with a weight ratio of 66 wt% of PVC, 2 wt% of Dicyanocobyrinic acid heptapropyl ester, and 132 wt% of DOA {Bis (2-ethylhexyl) adipate}. Obtaining; Dissolving the nitrite ion selective sensitive composition in 1 ml of solvent THF (tetrahydrofurane); Pouring the nitrite ion selective sensitive composition dissolved in 1 ml of solvent THF (tetrahydrofurane) into a glass tube of a predetermined diameter placed on a glass plate to evaporate the solvent THF into a predetermined shape; And cutting the molding to a predetermined thickness to produce a nitrite ion selective sensitized film.

A total nitrogen measuring apparatus using the ion selective membrane of the present invention, the total nitrogen measuring apparatus for quantifying the total nitrogen in the sample solution, the flow cell body of a predetermined shape consisting of a structure that can be separated into the upper cell body and the lower cell body; A flow path formed so as to penetrate from one side of the flow cell body to the other side, the inlet side and the outlet side having an inclination of a predetermined angle with respect to the middle portion, such that a sample solution flows; A PVC film layer attached to the lower surface inside the flow path to prevent bubble generation of the sample solution flowing through the flow path; Three electrode mounting portion is formed so as to be in the inner passage of the upper cell body and the electrode is mounted; An ammonium ion selective sensitizing membrane and a nitrite ion selective sensitizing membrane which are provided on the inner lower surfaces of both electrode mounting portions of the electrode mounting portion and selectively react with the ammonium ion and the nitrite ion in the sample solution flowing through the flow path; A sensitizing membrane fixing packing provided above the ion selective sensitizing membrane inside each electrode mounting portion provided with the ion selective sensitizing membrane to fix the ion selective sensitizing membrane, and having an internal reference solution filled therein; An internal reference electrode installed on an upper portion of each electrode mounting part in which the ion selective sensitive membrane is installed and in contact with the internal reference solution; A bi-core glass (Vycor glass) is installed in the lower portion of the electrode mounting portion of the electrode mounting portion so that one end is exposed to the sample solution flowing through the flow path; An internal reference solution filled into the electrode mounting portion in which the bicore glass is installed; And an internal reference electrode installed inside the electrode mounting portion in which the bicore glass is installed to maintain a constant potential at all times regardless of the sample solution conditions.

In the above configuration, 0.1M NH ₄ Cl (ammonium chloride) may be used as the internal reference solution filled in the electrode mounting portion in which the ammonium ion selective sensitive film is installed.

0.1 M NaNO ₂ (sodium nitrite) and 0.01 M NaCl (sodium chloride) may be used as the internal reference solution to be filled in the electrode mounting portion in which the above-mentioned nitrite ion selective sensitive film is installed.

KNO ₃ (potassium nitrate) may be used as the internal reference solution that is filled into the electrode mounting portion in which the aforementioned bicore glass is installed.

On the other hand, the internal reference electrode of the above-described configuration may be composed of Ag / AgCl.

Prior to describing the total nitrogen measuring apparatus using the ion selective electrode as described above, the ammonium ion selective electrode described in the present invention comprises an electrode mounting part formed on the flow cell body, an ammonium ion selective sensitive membrane, and an internal reference solution. The nitrite ion selective electrode refers to an electrode mounting portion formed in the flow cell body, the nitrite ion selective sensitive film, and an internal reference solution. In this case, when the ammonium ion selective electrode and the nitrite ion selective electrode are collectively described, it is expressed as a working electrode.

In addition, the external reference electrode refers to an electrode mounting portion formed on the flow cell body, bicore glass (Vycor glass), including the internal reference solution and the internal reference electrode.

On the other hand, when the total nitrogen measuring apparatus using the ion-selective electrode configured as described above is outlined, it is very deeply related to eutrophication of the river as described above, the actual sample solution may contain suspended matters, If eutrophication of rivers or lakes is severe, algae may be included during the sampling process.

Therefore, before proceeding with the kjeldahl reaction, it is essential to filter the foreign matter contained in the sample solution through the filter. On the other hand, organic nitrogen, ammonium ions, nitrate ions and nitrite ions are present in the sample solution from which foreign substances are filtered.

The next step is to stir well the sample solution under devarda's alloy and the nitrate ions are reduced to ammonium ions. This process results in the presence of organic nitrogen, nitrite and ammonium ions in the sample solution.

Here, a small amount of the sample solution is sent to the nitrite ion selective electrode to quantify the nitrite ion, and the remaining sample solution is reacted using potassium sulfate as a catalyst in the presence of sulfuric acid.

Through the above reaction, organic nitrogen species are decomposed to carbon dioxide, water, and ammonium bisulfate. Ammonium ions remain unchanged under acidic conditions. The remaining nitrite ions are oxidized and converted to nitrate ions.

Basic treatment in the next step generates ammonia gas, dissociates it in boric acid and quantifies the ammonium ion with an ammonium ion selective electrode. In order to quantify the amount of nitrate ions, it can be found by measuring the amount of ammonium ion before and after treating the sample solution with devarda's alloy.

As described above, the well-known kjeldahl reaction is not easy to measure nitrate ions and nitrite ions. In the present invention, the nitrate ions are reduced to ammonium ions using devarda's alloy, and then measured with an ammonium ion selective electrode and nitrite ions. Is measured using a nitrite ion selective electrode.

The nitrogen-containing organics in the sample solution described above are finally measured by using a kjeldahl reaction and converted into ammonium ions, and nitrite ions are measured using a nitrite ion selective electrode.

On the other hand, in the case of nitrate ion, the detection limit and the response time of the nitrate ion selective electrode are judged to be inadequate for use in the flow system, and are measured using ammonium ion selective electrode having good sensitivity after reduction to ammonium ion using devarda's alloy. .

As described above, the method of capturing and titrating ammonia gas using the kjeldahl reaction has limitations in the measurement of nitrate ions and nitrite ions, but the present invention using an ion selective electrode can solve such disadvantages.

In addition, by using a bicore glass (Vycor glass) as an external reference electrode, the flow cell body itself can serve as an electrode body to which the ion selective membrane can be mounted, thereby miniaturizing the detector portion.

Hereinafter, an ion selective sensitive composition, a method for producing an ion selective sensitive membrane using an ion selective sensitive composition, and a total nitrogen measuring apparatus using an ion selective sensitive membrane according to a preferred embodiment of the present invention will be described in detail.

1 is a flow chart showing a total nitrogen measurement method applying the Kjeldahl reaction according to the present invention.

As shown in FIG. 1, since the sample solution may contain various suspended substances, the sample passes through the filter and passes through step A. The sample solution in step A contains organic nitrogen, ammonium ions, nitrate ions, nitrite ions, and several other substances from which suspended solids are removed.

When the sample solution passed through step A is stirred in the presence of devarda's alloy, nitrate ions are reduced and converted to ammonium ions.

Therefore, in step B, organic nitrogen, nitrite ions, and ammonium ions generated by reducing existing ammonium ions and nitrate ions are present.

On the other hand, since the cation-selective electrode is hardly disturbed by the anion, and the anion-selective electrode is not disturbed by the cation, a part of the sample solution passing through step B is sent to the nitrite ion selective electrode, and the sensitive nitrite ion selective electrode is Measures nitrite ion.

When the remaining sample solution in step B is decomposed to sulfuric acid under a potassium sulfate catalyst, carbon in organic nitrogen is removed in the form of carbon dioxide, and the remainder is in the form of ammonium bisulfate. Under acidic conditions, ammonium ions do not change, and nitrite ions that have already been measured may be oxidized to nitrate ions.However, when the sample solution undergoing step C is treated under basic conditions, ammonium ions and ammonium bisulfate form ammonia gas. The remaining nitrate and nitrite ions do not interfere with the measurement. Ammonia gas itself dissolves well in solution and under acidic conditions this process is much easier.

The ammonia gas collected in step D is dissolved in boric acid and collected in step E as ammonium ions. Total nitrogen can be quantified by measuring the ammonium ion collected in step E using an ammonium ion selective electrode.

On the other hand, the sample solution in step A is not treated with devarda's alloy, and only the concentrations of ammonium ion and organic nitrogen in which the concentration of nitrite ion and nitrate are deducted from the total nitrogen concentration are measured by the steps C, D, and E. do.

In addition, if a small amount of the sample solution in step A is sent directly to the ammonium ion selective electrode, only the concentration of ammonium ion originally present in the sample solution may be measured.

As a result, it is possible to develop a device that can measure the concentration of organic nitrogen, nitrite ion, nitrate ion, and ammonium ion according to the user's request.

2 is a structure of the working electrode to be introduced into the flow cell according to the present invention, FIG. 3 is a structure of an external reference electrode to be introduced into the flow cell according to the present invention, and FIG. 4 is a working electrode and an external reference electrode according to the present invention. It is the structure of one flow cell.

The total nitrogen measuring apparatus using the ion selective electrode according to the present invention will be described in detail as follows.

First, as shown in FIGS. 2 to 4, the total nitrogen measuring apparatus using the ion selective electrode according to the present invention is penetrated from one side of the flow cell body 100 and the flow cell body 100 having a vertical separation structure to the other side. The flow path body 110 is formed to be attached to the lower surface of the flow path, the sample solution flow path 110, the PVC film layer 120 to prevent the generation of bubbles of the sample solution flowing through the flow path 110, the flow cell body 100 Three electrode mounting parts 106a, 106b, and 106c formed on the upper side of the inner surface of the inner electrode and the internal reference electrode, which are formed to be inwardly connected to the flow path 110, respectively, on the lower surfaces of the inner surfaces of the two electrode mounting parts 106a and 106c. The ammonium ion selective sensitive membrane 130 and the nitrite ion selective sensitive membrane 130a to be installed are filled with internal reference solutions 145 and 145a to fix the ion selective sensitive membrane 130 and 130a. 140, 140a), ion selective sensitivity Installed at the upper portions of the electrode mounting portions 106a and 106c on which the 130 and 130a are installed, and are installed below the inner reference electrodes 150 and 150a and the middle electrode mounting portion 106b in contact with the internal reference solutions 145 and 145a. Of the internal reference solution 165 and the electrode mounting unit 106b provided with the bicore glass 160 to be filled into the interior of the electrode mounting unit 106b in which the bicore glass 160 and the bicore glass 160 are installed. It is provided with an internal reference electrode 170 that is installed inside to maintain a constant potential at all times regardless of the sample solution conditions. At this time, the electrodes 150, 150a, and 170 mounted on the electrode mounting parts 106a, 106b, and 106c are screwed to the tops of the electrode mounting parts, 106a, 106b, and 106c, respectively, by the caps 180a, 180b, and 180c that are screwed onto the upper parts of the electrode mounting parts, respectively. Is mounted.

In the above-described configuration, the flow cell body 100 has a separation structure consisting of the upper cell body 102 and the lower flow cell body 104.

The flow path 110 is a sample solution flows, the flow path 110 is formed so as to penetrate from one side of the flow cell body 100 to the other side, the inlet (110a) side and the outlet (110b) side with respect to the middle portion at a predetermined angle It is formed to have a slope of.

In more detail, the flow path 110 forms a groove in each of the lower surface of the upper cell body 102 and the upper surface of the lower flow cell body 104 of the flow cell body 100, and then the upper cell body 102. ) And the lower flow cell body 104 are joined together to form a flow path 110 through which a sample solution can flow.

At this time, the PVC film layer 120 is formed on the surface of the groove formed on the lower flow cell body 102 side. That is, the PVC film layer 120 is formed on the lower surface inside the flow path 110. As such, by forming the PVC film layer 120 on the lower surface of the flow path 110, bubbles in the sample solution flowing through the flow path 110 are prevented.

On the other hand, the flow path 110 formed as described above is formed so as to penetrate from one side to the other side, the inlet port 110a side and the outlet port 110a side with respect to the middle portion of the flow path 110 is formed to have a predetermined angle of inclination. As illustrated in FIG. 4, the inlet 110a and the outlet 110b may be formed in a vertical direction with respect to the horizontal middle portion of the flow path 110 so that the inlet 110a and the outlet 110b may be parallel to each other. This structure is useful for preventing bubbles from occurring when the sample solution flows inside the flow path 110.

The electrode mounting portions 106a, 106b, and 106c are for mounting the internal electrodes 150 and 150a and the internal reference electrode 170. The electrode mounting portions 106a, 106b and 106c are located at the upper positions of the upper cell body 102. Three are formed to be inwardly communicated with the flow path 110 in the vertical direction.

The ammonium ion selective sensitized membrane 130 and the nitrite ion selective sensitized membrane 130a are selectively sensitive to ammonium ions and nitrite ions, and the ion selective sensitized membranes 130 and 130a are electrode mounting portions 106a and 106b, respectively. It is provided on the inner lower surfaces of the electrode mounting portions 106a and 106c on both sides of the 106c, and selectively reacts with the ammonium ion and the nitrite ion in the sample solution flowing through the flow path 110.

The sensitized membrane fixing packings 140 and 140a are used to fix the ion-selective sensitized membranes 130 and 130a provided on the inner lower surfaces of the electrode mounting portions 106a and 106c on both sides. 140a is installed above the ion-selective sensitive membranes 130 and 130a in the electrode mounting portions 106a and 106c where the ion-selective sensitive membranes 130 and 130a are installed to move the ion-selective sensitive membranes 130 and 130a to the bottom surface. The close contact prevents the sample solution flowing through the flow path 110 from penetrating into the electrode mounting portions 106a and 106c.

As described above, the O-rings 190 and 190a are inserted into the upper portions of the sensitized membrane fixing packings 140 and 140a while the sensitized membrane fixing packings 140 and 140a are installed in the electrode mounting portions 106a and 106c. The internal reference solutions 150 and 150a filled in the electrode mounting portions 106a and 106c by mounting the internal reference electrodes 150 and 150a upward through the caps 180a and 180c to the upper portions of the electrode mounting portions 106a and 106c. Make contact with

On the other hand, the bi-core glass 160 is installed below the middle electrode mounting portion 106b of the electrode mounting portions 106a, 106b, 106c so that one end is exposed to the sample solution flowing through the flow path 110. At this time, the bicore glass 160 to be installed should have a sealed structure so that the sample solution does not flow into the electrode mounting portion 106b of the intermediate.

As described above, the internal reference solution 165 to be filled into the electrode mounting portion 106b is filled in the state in which the bicore glass 160 is installed, and the upper portion thereof is irrespective of the condition of the sample solution through the lid 180b. The internal reference electrode 170 that maintains a constant potential at all times is mounted to contact the internal reference solution 165 filled in the electrode mounting portion 106b.

As described above, according to the present invention, the ammonium in the sample solution is formed by using a potential difference generated between the reference electrode and the working electrode while the sample solution flows through the inlet 110a to the outlet 110b. Total nitrogen is detected by quantifying ions and nitrite ions.

On the other hand, the composition of the ion-selective sensitive film (130, 130a) used in the present invention is as follows. The ammonium ion selective sensitized membrane 130 is 66 wt% of polyvinyl chloride (PVC), 2 wt% Nonactin, 132 wt% DOA {Bis (2-ethylhexyl) adipate}, and the nitrite ion selective sensitized membrane 130a is PVC. 66wt%, Dicyanocobyrinic acid heptapropyl ester 2wt%, DOA {Bis (2-ethylhexyl) adipate} 132wt%.

With this composition, it is dissolved in 1 ml of solvent THF (tetrahydrofurane), poured into a glass tube of 22 mm diameter placed on a glass plate, and the solvent (THF) is left in the air for one day to evaporate.

The ion-selective sensitive membranes 130 and 130a thus manufactured are cut into a 5.5 mm circular shape and mounted on the inner lower ends of the electrode mounting portions 106a and 106c of the flow cell body 100.

In the present invention, the conventional electrode (ion selective electrode) is not introduced into the flow cell body 100, but the ion-selective sensitive membranes 130 and 130a are mounted on the flow cell body 100 itself so that the flow cell body 100 is formed. It was possible to act as an electrode body.

As shown in FIGS. 2 and 4, since the ion-selective sensitive films 130 and 130a using PVC have weak adhesion, the ion-selective sensitive films 130 and 140 may be formed by using a membrane packing piece (140,140a). 130a) is fixed. The ion-selective sensitive membranes 130 and 130a are mounted on the lower inner side of the electrode mounting portions 106a and 106c of the flow cell body 100, and the middle portion of the sensitive membrane fixing packings 140 and 140a is vacant, Reference solutions 145 and 145a are filled.

As shown in FIGS. 2 to 4, the screw caps are mounted on the inner wall surfaces of the electrode mounting parts 106a, 106b, and 106c by turning the caps 180a, 180b, and 180c, and the internal electrodes 150, 150a and the internal standard are closed. Ag / AgCl was used for the electrodes 150, 150a, and 170.

On the other hand, the lower middle portion of the lid (180a, 180b, 180c) is also empty, Ag / AgCl is in contact with the internal reference solution (145, 145a, 165). O-rings 190 and 190a having excellent elasticity are inserted between the caps 180a, 180b, and 180c and the sensitized membrane fixing packings 140 and 140a to fix the sensitized membrane fixing packings 140 and 140a.

In case of the ammonium ion selective electrode and the nitrite ion selective electrode, the internal reference solutions 145 and 145a use 0.1 M NH ₄ Cl (ammonium chloride) when the ammonium ion selective sensitive membrane 130 is mounted. When the selective sensitized membrane 130a is mounted, 0.1 M NaNO ₂ (sodium nitrite) and 0.01 M NaCl (sodium chloride) are used in combination.

The ion-selective sensitive films 130 and 130a at the lower inner side of the electrode mounting parts 106a and 106c are fixed while the packings for fixing the sensitive film 140 and 140a are pressed from above. As such, when the ion-selective sensitive membranes 130 and 130a are pressed from above through the packing for fixing the membranes 140 and 140a, the ion-selective sensitive membranes 130 and 130a to which the plasticizer is added to the PVC are flexible, so that the flow path actually flows through the solution. Protruding convex up to (110).

Therefore, the ion-selective sensitive membranes 130 and 130a are sufficiently exposed to the sample solution and are stable, and can always be kept fresh by the continuously flowing sample solution.

As shown in FIGS. 3 and 4, Ag / AgCl was used for the internal reference electrodes 150, 150a, and 170, and bicore glass 160 (Vycor glass) was used for the junction material.

On the other hand, the internal reference solution 165 to be filled in the electrode mounting portion (106b) is good to use that there is little difference in the mobility of ions, such materials are representative of KCl (potassium chloride) and KNO ₃ (potassium nitrate) Can be.

The nitrite ion selective electrode used in the present invention may be disturbed by nitrate ions, and the ammonium ion selective electrode may be disturbed by potassium ions. In the present invention, such a disturbance is not fundamentally solved. In the present invention, KNO ₃ (potassium nitrate) solution having a somewhat less interference level was used as the internal reference solution 165 of the external reference electrode, and the concentration was 1M, and the weight ratio was 10wt. Glycerol (glycerol) was mixed to be%. Glycerol is a highly viscous neutral material, and if a small amount of this material is mixed, the internal reference solution 165 of the external reference electrode can control the rate at which the bicore glass 160 flows out to some extent. The bi-core glass 160 was also such that the lower surface of the bi-core glass 160 can reach the entire surface sufficiently.

The working electrode and the reference electrode configured as described above have a structure as shown in FIG.

If the working electrode and the reference electrode are sufficiently immersed in the aqueous solution, the effect of electrical noise is small and the signal is stable.However, when the flow cell is introduced in the flow system, the actual sensitive part of the working electrode and the reference electrode and the flow path through which the solution passes ( 110) The part should be designed to be very stable and sufficiently in contact to maximize the performance of the ion selective electrode.

Figure 4 is a structure of the entire flow cell showing the position of the working electrode and the reference electrode as described above can be largely divided into the top and bottom. A common problem in all measuring instruments that use flow meters is that bubbles are generated. This problem occurs when a solution having a high surface tension passes through a flow path where the surface is not smooth.

In the present invention, the cocktail solution (cocktail solution) mixed with PVC 66mg, THF 800μl, DOA 143μl is poured on the bottom of the flow path 110 of the flow cell body 100 to blow THF in the air to form a thin and smooth PVC film layer 120 ) To minimize bubble formation.

On the other hand, in the flow system, since the amount of the solution flowing between the working electrode and the reference electrode is very small, if the distance between the two electrodes is too far, the electrical connection in the sample solution is lost.

Therefore, the flow cell body 100 designed in the present invention maintains a sufficient distance between the reference electrode and the working electrode by placing the working electrodes on both sides with the external reference electrode in the center. In addition, the inlet part 110a (inlet) through which the sample solution flows and the outlet part 110b (outlet) exiting through the flow path 110 of the flow cell body 100 prevent air bubbles and effectively inflow and outflow of the sample solution. In order to push up from the bottom to the top using the force of the pump was designed.

5 is a sensitivity curve of the ammonium ion selective electrode according to the present invention, Figure 6 is a sensitivity curve of the nitrite ion selective electrode according to the present invention.

As shown in Figs. 5 and 6, the device according to the invention shows very good selectivity and the response time is also very fast. Even if the response to the target ions is excellent, if the response time is slow, there is a problem to use in the flow system.

In other words, in order to introduce the ion-selective electrode into the system, more than a certain flow rate is required in consideration of the measurement time, but when the response time is very slow, a small amount of the assay solution and the sample solution are already present before the sensitive membrane of the ion-selective electrode is sensitive. As it passes through the sensitizer, it is impossible to introduce it into the actual equipment.

7 is a sensitivity curve under the wall-jet of the ammonium ion selective electrode according to the present invention, Figure 8 is a sensitivity curve under the wall-jet of the nitrite ion selective electrode according to the present invention.

7 and 8 are experimental results using the wall-jet method, and when applied to the flow cell as in the present invention, it is expected that a greater response can be obtained.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the technical idea of the present invention.

As described above, according to the present invention, after converting a solution mixed with various ionic species into a form that can be measured by an ion-selective electrode through an appropriate process, it is converted between a working electrode and a reference electrode using Vycor glass. By making it possible to quantify using the generated potential difference, it is possible to measure total nitrogen more quickly and accurately.

The ion-selective electrode used in the total nitrogen measuring apparatus according to the present invention is very easy to manufacture, maintain, and manage, and the cost is low, and thus the cost can be reduced.

In addition, according to the present invention has the effect of quantifying the organic nitrogen, nitrite ion, nitrate ion, ammonium ion as described above.

On the other hand, the ion-selective sensitive membrane is mounted on the flow cell body itself, and bicore glass (Vycor glass) by making a reference electrode from a porous (junction) material has the effect of enabling the miniaturization of the core of the measuring device.

In addition to the effects described above, the total nitrogen measuring apparatus using the ion selective electrode according to the present invention is expected to be able to reduce the foreign currency to many environmental companies that manage the environmental pollution of rivers and lakes.

Claims (9)

An ammonium ion selective sensitive composition prepared by mixing at a weight ratio of 66 wt% of PVC (poly vinyl chloride), 2 wt% of Nonactin, and 132 wt% of DOA {Bis (2-ethylhexyl) adipate}. 66% by weight of polyvinyl chloride (PVC), 2% by weight of Nonactin, and 132% by weight of DOA {Bis (2-ethylhexyl) adipate} to obtain an ammonium ion selective sensitive composition; Dissolving the ammonium ion selective sensitive composition in 1 ml of solvent THF (tetrahydrofurane); Pouring ammonium ion selective sensitive composition dissolved in 1 ml of the solvent THF (tetrahydrofurane) into a glass tube having a predetermined diameter placed on a glass plate to evaporate the solvent THF into a predetermined shape; And The method of manufacturing an ammonium ion selective sensitized membrane comprising the step of cutting the molding to a predetermined thickness to produce an ammonium ion selective sensitized membrane. A nitrite ions selective sensitive composition prepared by mixing at a weight ratio of 66 wt% of PVC, 2 wt% of dicyanocobyrinic acid heptapropyl ester, and 132 wt% of DOA {Bis (2-ethylhexyl) adipate}. Obtaining a nitrite ion selective sensitive composition by mixing at a weight ratio of 66 wt% of PVC, 2 wt% of Dicyanocobyrinic acid heptapropyl ester, and 132 wt% of DOA {Bis (2-ethylhexyl) adipate}; Dissolving the nitrite ions selective sensitive composition in 1 ml of solvent THF (tetrahydrofurane); Pouring the nitrite ion selective sensitive composition dissolved in 1 ml of the solvent THF (tetrahydrofurane) into a glass tube having a predetermined diameter placed on a glass plate to evaporate the solvent THF into a predetermined shape; And And cutting the molding to a predetermined thickness to produce a nitrite ion selective sensitized film. In the total nitrogen measuring device for quantifying the total nitrogen in the sample solution, A flow cell body of a predetermined shape having a structure capable of being separated into an upper cell body and a lower cell body; A flow path formed so as to penetrate from one side of the flow cell body to the other side, the inlet side and the outlet side having an inclination of a predetermined angle with respect to an intermediate portion, and the sample solution flows therethrough; A PVC film layer attached to a lower surface of the flow path to prevent bubble generation of a sample solution flowing in the flow path; Three electrode mounting parts formed in the upper cell body so as to communicate with the flow path and mounted with electrodes; An ammonium ion selective sensitization membrane and a nitrite ion selective sensitization membrane which are installed on the inner lower surfaces of both electrode mounting portions of the electrode mounting portion and selectively react with the ammonium ion and the nitrite ion in the sample solution flowing through the flow path; A sensitizing membrane fixing packing installed above the ion selective sensitizing membrane inside each electrode mounting portion in which the ion selective sensitizing membrane is installed to fix the ion selective sensitizing membrane, while the internal reference solution is filled therein; A working electrode which is installed above each electrode mounting part in which the ion-selective sensitive membrane is installed and contacts the internal reference solution; A bi-core glass (Vycor glass) which is installed in the lower portion of the electrode mounting portion of the electrode mounting portion so that one end is exposed to the sample solution flowing through the flow path; An internal reference solution filled into the electrode mounting portion in which the bicore glass is installed; And Total nitrogen measurement apparatus using an ion-selective sensitive membrane comprising an internal reference electrode which is installed inside the electrode mounting portion is provided with the bicore glass to maintain a constant potential at all times regardless of the conditions of the sample solution. The total nitrogen measuring apparatus using an ion selective sensitized membrane according to claim 5, wherein 0.1M NH ₄ Cl (ammonium chloride) is used as an internal reference solution filled in the electrode mounting portion in which the ammonium ion selective sensitized membrane is installed. 7. The ion selectivity of claim 6, wherein 0.1 M NaNO ₂ (sodium nitrite) and 0.01 M NaCl (sodium chloride) are used as an internal reference solution to be filled in the electrode mounting portion in which the nitrite ion selective sensitive film is installed. Total nitrogen measuring device using induction membrane. 8. The ion-selective sensitive membrane according to any one of claims 5 to 7, wherein KNO ₃ (potassium nitrate) is used as an internal reference solution filled into the electrode mounting portion in which the bicore glass is installed. Total Nitrogen Measuring Device. The apparatus of claim 8, wherein the internal reference electrode is Ag / AgCl.