KR102121732B1 - (Electrolytic eluent modification device for suppressed ion chromatography and ion chromatography system with the same - Google Patents

Abstract

The present invention relates to an online automatic modification device for a suppressor-type ion chromatography eluent and an ion chromatography system having the same. The device includes: a main body where an ion exchange space portion provided on one side is provided with a supply path for deionized water or eluent supply and a discharge path is formed for outward discharge of the deionized water or eluent after cation or anion addition in the ion exchange space portion; a storage tank provided in the main body so as to be connected to the ion exchange space portion and storing an electrolyte solution for the cation or anion addition; an ion exchange portion allowing either the cation or the anion to pass by separation between the supply path and storage tank sides in the ion exchange space portion; first and second electrodes respectively installed on the supply path side and the storage tank side across the ion exchange portion and respectively supplying anode and cathode currents such that the cation or anion provided from the electrolyte solution is supplied to the supply path side; and a current supply control unit controlling the current supplied to the first and second electrodes. According to the present invention, automatic ionization equilibrium shift of water causing a decline in sensitivity and a nonlinear response in a low concentration region in suppressor-type ion chromatography is suppressed and addressed. Accordingly, the linear range of a calibration curve can be extended to a lower region and detection power can be improved.

Description

On-line automatic transformation device of suppressor type ion chromatography eluent and ion chromatography system having the same {{Electrolytic eluent modification device for suppressed ion chromatography and ion chromatography system with the same}

The present invention relates to an on-line automatic transformation device for a suppressor type ion chromatography eluent and an ion chromatography system having the same, and more specifically, for the reduction of sensitivity and nonlinear response problems in a low concentration region in the suppressor type ion chromatography method. The present invention relates to an on-line automatic deforming device of a suppressor type ion chromatography eluent and an ion chromatography system having the same, by suppressing the automatic ionization equilibrium shift of the cause.

In general, ion chromatography refers to a technique for separating ionic species by chromatography. Ion chromatography is a field of high-speed liquid chromatography (HPLC), in which a mobile phase called eluent exists and a fixed phase exists in the ion column. The sample solution is transferred to the ion column by the eluent, and the rate of movement of ions varies according to the difference in affinity of the ions, so that separation for each ion occurs.

Looking at this process in more detail, the eluent flows into the ion chromatography by the pump, and the sample entering the sample injection unit is pushed by the eluent and moves to the ion column. In the ion column, after separation due to the ionic mobility according to the affinity of the ions, the sample and the eluent exiting the column pass through a suppressor. The suppressor lowers the conductivity of the eluent and increases the conductivity of the sample, making it easier to detect ions. The sample passing through the suppressor is moved to an electrical conductivity detector to detect conductivity. Conductivity is checked by communicating with a computer or an integrator to check the composition of ions, and the concentration of ions is measured using the area occupied by each maximum value since the conductivity is proportional to the concentration of each ion.

As a related art related to ion chromatography, there has been disclosed "Ion Chromatography" of Korean Patent Publication No. 10-1997-0030290, which includes a gradient pump for supplying a condensate, an eluate of the gradient pump and an N ₂ gas valve A coloring reagent transfer unit for mixing the generated reagent supplied through the eluate, a detection unit for detecting and measuring impurities by loading the mixed solution of the reagent transfer unit, and a detection ion display unit for receiving and displaying measurement data of the detection unit, It includes a control timer for switching control to achieve automatic operation and safety according to a predetermined time set by the valve and the detection unit of the gradient pump and the coloring reagent transfer unit.

In addition to these conventional technologies, in the case of ion chromatography, which is a suppressor type using senic acid or senbase eluent in conventional ion chromatography, it has many advantages such as ease of use, concentration gradient elution and high detection power, and is currently most widely used. However, in the low concentration region of the sub-μM level, the calibration curve is bent and has a problem of low sensitivity.

This problem appears due to the nonlinear response due to the automatic ionization equilibrium of water. In the case of anion analysis using a carbonic acid eluent, the problem of nonlinear sensitization was recognized earlier, and a number of previous studies have been conducted.However, in cation analysis using a senic acid eluent, dissociation of the analyte species at concentrations of sub-mM level is automatically ionized by water. The effect on is neglected. However, when the concentration of the analyte species is lowered to a level of sub-μM or less, a non-linear problem appears, and the degree of non-linearity is more severe than that of an anion. 1 is a non-linear response calibration curve of anions and cations in a low concentration section obtained by theoretical calculation, respectively.

The problem of the nonlinear response is due to the fact that water acts as an acid or a base in a low concentration region, so that the ionization equilibrium of the water moves, thereby reducing the background conductivity value. As shown in FIG. 2, since the ionization equilibrium of water moves due to H ⁺ or OH ⁻ which forms a pair acid/pair base with the analyte ion species in the region where the analyte ion species appear, the background conductivity at the time when the analytical peak appears is reduced. The background conductivity because a value of infinite equivalent conductivity of 199.1 S · cm in size compared to the ² / mol (25 ℃) ^- paired endless equivalent conductivity of the acid H ⁺ for cation 349.6 S · cm ² / by mol (25 ℃) OH The problem of reduction occurs more severely, and even the analytical peak appears to be negative. Therefore, the size of the actual analysis peak becomes smaller than the ideal value, and not only the detection power decreases, but also the degree of background conductivity decreases depending on the concentration of the analyzed ion species, so the calibration curve appears non-linear, making it difficult to quantify. .

In addition, it is essential to add a certain amount of impurities to the eluent in order to quantitatively analyze low-concentration inorganic ions at the sub-μM level without a nonlinear response problem. However, it is difficult to manufacture and use the eluent containing a certain amount of impurities offline, and it is very difficult to accurately use the eluent at the same concentration every time a new preparation is made. In addition, when analyzing anions, carbonate contamination in the eluent should be controlled, and the affinity of the column functional group is relatively small, so the eluent gradient program is applied to separate analysis of F ^- and organic acids, etc., that appear near the water dip. Therefore, in order to add a certain concentration of impurities in the eluent, it was necessary to develop an apparatus for adjusting the concentration of the impurities in the eluent on-line.

In order to solve the problems of the prior art as described above, the present invention is to solve this by suppressing the automatic ionization equilibrium movement of water, which is a cause of desensitization and nonlinear response problems in a low concentration region in the suppressor type ion chromatography method, The aim is to extend the straight line range of the calibration curve to a lower area and improve the detection power.

Other objects of the present invention will be easily understood through the description of the following examples.

In order to achieve the above object, according to an aspect of the present invention, as an apparatus for supplying cations or anions to the eluent of the ion chromatography system, so that deionized water or eluent is supplied to the ion exchange space provided on one side The main body is formed in the supply path is formed, the discharge path is formed so that the deionized water or eluent to which the cation or anion is added in the ion exchange space portion is discharged to the outside; A storage tank provided in the main body to be connected to the ion exchange space, and storing an electrolyte solution for adding the cations or anions; An ion exchange unit separating the supply path side and the storage tank side in the ion exchange space to pass only one of positive and negative ions; The first and the positive electrode current and the negative electrode current are respectively provided on the supply path side and the storage tank side, and the positive or negative currents provided from the electrolyte solution are provided to the supply path side with the ion exchange part interposed therebetween. A second electrode; And a current supply control unit that controls current supplied to the first and second electrodes. An on-line automatic transformation device for a suppressor type ion chromatography eluent is provided.

The ion exchange part, a plurality of frits (Frit) is provided to be spaced apart from each other, a cation exchange sheet is laminated between the frits, a cation exchange membrane is interposed between the cation exchange sheets, the ions A cation exchange tube is installed on the outlet side of the exchange space to suppress the separation of the frit, the storage tank, the electrolyte solution is an RbOH solution, and the first electrode is a cathode electrode installed on the supply path side, The second electrode may be an anode electrode installed on the storage tank side.

The ion exchange unit is provided so that a plurality of frits are spaced apart from each other in the ion exchange space, an anion exchange sheet is laminated between the frits, and an anion exchange membrane is interposed between the anion exchange sheets, An anion exchange tube is installed at the entrance side of the exchange space to prevent the frit from leaving, and in the storage tank, the electrolyte solution is P-TSA (para toluenesulfonic acid), and the first electrode is on the supply path side. It is an anode electrode to be installed, the second electrode may be a cathode electrode installed on the storage tank side.

The first electrode is made of a Pt wire installed to extend to the end of the supply path through the main body, a coil portion is provided at the end, and the second electrode is Pt installed to extend to the entrance side of the storage tank A Pt ribbon made of a wire and increasing an area at an end may be provided.

In the supply path, a first expansion tube having a diameter extending to a side to which the deionized water or eluent is supplied is connected, and in the discharge path, a diameter is extended to a side where the deionized water to which the ions are added or the eluent is discharged. The second extension tube can be connected.

According to another aspect of the present invention, a storage container in which deionized water is stored; An ion trap column for removing impurities of anions or cations present in deionized water transferred by the pump from the storage container; An eluent maker for preparing deionized water that has passed through the ion trap column as an eluent; A degasser for removing gas inside the eluent produced by the eluent maker; An analysis column that separates the sample injected by the injection valve by the eluent that has passed through the degasser; A suppressor to remove ions having opposite polarities of ions to be detected contained in the eluent that has passed through the analysis column; And an electrical conductivity detector that performs quantitative analysis through measurement of the electrical conductivity of the ions to be analyzed in the sample that has passed through the suppressor; and an online automatic modification device for a suppressor type ion chromatography eluent according to an aspect of the present invention. Is provided with an ion chromatography system having an on-line automatic modification of the eluent, which adds a defined concentration of cations or anions to deionized water or eluent.

The online automatic deforming device of the suppressor type ion chromatography eluent may be installed between the ion trap column and the eluent maker.

The on-line automatic transformation device of the suppressor type ion chromatography eluent may be installed between the analysis column and the suppressor.

The on-line automatic deforming device of the suppressor type ion chromatography eluent may be installed between the suppressor and the electrical conductivity detector.

The suppressor may be operated in a recycling mode in which a solution discharged to the outside is circulated.

The suppressor may be operated in an external supply mode for supplying clean distilled water from which foreign matter has been removed by the foreign matter removal column.

According to the on-line automatic transformation device of the suppressor-type ion chromatography eluent according to the present invention and the ion chromatography system having the same, the suppression-type ion chromatography method automatically reduces the sensitivity of the low concentration region and the water which is the cause of the nonlinear response problem. By suppressing the ionization equilibrium shift, this can be solved, and the straight line range of the calibration curve can be extended to a lower region, and detection power can be improved.

1 is a graph showing a non-linear response of an anion (left) and a cation (right) calibration curve in a low concentration region of a sub-μM level of ion chromatography using a conventional sen base and sen acid as an eluent.
Figure 2 shows the calculated value of the Li+ ion analysis peak in pure water (35 °C: sample concentration = 0.1 μmol/L, F = 1 mL/min, V = 5 μl, σ = 0.043 min).
3 is a cross-sectional view showing an on-line automatic deformation device of a suppressor type ion chromatography eluent according to a first embodiment of the present invention.
4 is a cross-sectional view showing an on-line automatic deforming device of a suppressor type ion chromatography eluent according to a second embodiment of the present invention.
5 is a block diagram showing an ion chromatography system having an on-line automatic deformation device for eluents according to a first embodiment of the present invention.
6 is a block diagram showing an ion chromatography system having an on-line automatic deformation device for eluents according to a second embodiment of the present invention.
7 is a block diagram showing an ion chromatography system having an on-line automatic deformation device for eluent according to a third embodiment of the present invention.
8 is a block diagram showing an ion chromatography system having an on-line automatic deformation device for eluents according to a fourth embodiment of the present invention.
Figure 9 shows the principle of operation for the cation system of the automatic on-line deformer of the suppressor type ion chromatography eluent according to the present invention.
10 is a graph showing a change in background conductivity of a cation chromatography system using an on-line automatic modification device of a suppressor type ion chromatography eluent according to a first embodiment of the present invention.
11 is a graph showing the change in the background conductivity of the cation chromatography according to the strength of the current in the on-line automatic modification device of the suppressor type ion chromatography eluent according to the first embodiment of the present invention.
12 is an analytical chromatogram (1.Li ⁺ 1 μg/L, 2.Na when mounted behind a suppressor under cationic gradient conditions in an on-line automatic transformation device of a suppressor type ion chromatography eluent according to a second embodiment of the present invention. ⁺ 2.6 μg/L 3. NH ⁴⁺ 2.6 μg/L, 4. MA 4.6 μg/L, 5. K ⁺ 4.6 μg/L and DMA 6.6 μg/L, 6.TMA 18 μg/L, 7. Mg ^{2 +} 3.6 μg/L, 8.Ca ²⁺ 7 μg/L).
Figure 13 is a calculated value of the lithium ion analysis peak in the eluent containing 0.5 μmol / L dipropylamine according to the present invention (, 35 ℃: CS = 0.1 μmol/L, F = 1 mL/min, V = 5 μL, σ = 0.043 min).

The present invention can be variously changed, and may have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood as including all modifications, equivalents, and substitutes included in the technical spirit and scope of the present invention, and to be modified in various other forms. May be, the scope of the present invention is not limited to the following examples.

Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings, and the same reference numerals will be assigned to the same or corresponding components regardless of reference numerals, and redundant description thereof will be omitted.

3 is a cross-sectional view showing an on-line automatic deformation device of a suppressor type ion chromatography eluent according to a first embodiment of the present invention.

Referring to FIG. 3, the online automatic deformation apparatus 100 of a suppressor type ion chromatography eluent according to a first embodiment of the present invention is an apparatus for supplying positive or negative ions to an eluent of an ion chromatography system, the body 110 ), a storage tank 120, an ion exchange unit 130, a first electrode 140, a second electrode 150, and a current supply control unit 160 (shown in FIG. 5 ).

The main body 110 is formed with a supply path 113 for supplying deionized water or eluent to the ion exchange space 111 provided on one side, and deionized water in which cations or anions are added in the ion exchange space 111 Alternatively, an emission path 115 is formed through which the eluent is discharged to the outside. In addition, a supply port 114 for connecting a supply pipe of deionized water or eluent may be provided at the end of the supply path 113, and a discharge pipe of deionized water or eluent to which cations or anions are added is added to the end of the discharge path 115. A discharge port 116 for connection may be provided. In addition, the main body 110 is connected to the storage tank 120 through the ion exchange space 111, and the storage tank 120 by the airtight cap 112 screwed to surround the ion exchange space 111. It is possible to prevent leakage of the connecting portion.

The storage tank 120 is provided on the main body 110 to be connected to the ion exchange space 111, and an electrolyte solution for adding cations or anions is stored. It can be fixed to the main body 110 by a coupling method, it can be fixed directly, or fixed via a cap or a fitting member, etc., the exhaust port 121 can be formed on the top for exhaust.

The ion exchange unit 130 separates the supply path 113 and the storage tank 120 from the ion exchange space 111 so that only one of positive and negative ions passes through.

The first and second electrodes 140 and 150 are provided on the supply path 113 side and the storage tank 120 side with the ion exchange unit 130 therebetween, and positive or negative ions provided from the electrolyte solution are supplied. The anode current and the cathode current are respectively supplied to the side of (113). Here, the first electrode 140 may be formed of a Pt wire installed to extend to the end of the supply path 113 through the main body 110, and a coil part 141 may be provided at the end. The second electrode 150 may be formed of a Pt wire that is installed to extend to the entrance side of the storage tank 120, and a Pt ribbon 151 to increase the area at the end may be provided. First and second connectors 142 and 152 for connection of the power supply line may be provided at the power input side of each of the first and second electrodes 140 and 150, respectively, so that current is supplied from the current supply control unit 160.

The current supply control unit 160 (shown in FIG. 5) is to finely adjust the current supplied to the first and second electrodes 140 and 150. The current supply control unit 160 may supply the amount of current required to the first and second electrodes 140 and 150 through data obtained in advance through experimentally or computationally calculating the amount of ions according to the amount of current. It is possible to supply the amount of current required to perform.

When the on-line automatic deforming device 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention is for a cation system, the ion exchange unit 130 has a plurality of frits in the ion exchange space unit 111. ; 131) may be provided to be spaced apart from each other, a cation exchange sheet 132 may be stacked between frits 131, and a cation exchange membrane 133 may be interposed between the cation exchange sheets 132, A cation exchange tube 134 may be installed on the outlet side of the ion exchange space 111 by screwing or the like to suppress the separation of the frit 131. In addition, the storage tank 120 may be an electrolyte solution is an RbOH solution. In addition, the first electrode 140 may be a cathode electrode installed on the supply path 113 side, and the second electrode 150 may be an anode electrode installed on the storage tank 120 side. The cation exchange sheet 132 and the cation exchange membrane 133 function to pass only cations. Meanwhile, in this embodiment, the cationic system will be mainly described.

On the other hand, the on-line automatic deforming device 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention is for anion systems, the ion exchange unit is provided so that a plurality of frits are spaced apart from each other in the ion exchange space It can be, an anion exchange sheet can be laminated between the frits, an anion exchange membrane can be interposed between the anion exchange sheets, and an anion exchange tube can be installed at the entrance side of the ion exchange space to suppress the separation of the frits. have. In addition, the storage tank may be P-TSA (para toluenesulfonic acid). In addition, the first electrode may be an anode electrode installed on the supply path side, and the second electrode may be a cathode electrode installed on the storage tank side. Here, the anion exchange sheet and the anion exchange membrane act to pass only anions.

RbOH solution and cation to prevent Rb ⁺ from being added as an eluent even when no current is applied due to the Donnan equilibrium, a phenomenon in which ionic species are unevenly distributed at the interface of the cation exchange membrane 133 in this embodiment. The area where the exchange membrane 133 contacts the resin was minimized. This is because the selection of the RbOH solution is a solution in which there is no risk of degradation or denaturation by electricity without affecting the peak of the analyte ion during general cation analysis. In addition, the size of the device was miniaturized to minimize the exchange capacity of the ion exchange portion, thereby increasing the response efficiency.

The portion in direct contact with the RbOH solution is inserted into the cation exchange tube 134 and knotted to prevent the frit 131 from protruding toward the storage tank 120 of the RbOH solution due to high system pressure. In addition, the cation exchange membrane 133 is inserted between the frit 131 and the cation exchange sheet 132 to withstand a high pressure of about 1300 psi applied from the ion chromatography system, and then between the cation exchange sheet 132. The cation exchange membrane 133 was located. It was confirmed that the RbOH addition device thus prepared withstands a high pressure of about 1900 psi. In addition, in order to increase the efficiency of the addition device, the first electrode 140 forms a coil part 141 by rounding the end in a circular shape, and the Pt ribbon 151 is attached to the second electrode 150 to maximize the area of the electrode. Did.

According to this embodiment, the cation exchange membrane 133 is placed at the interface, and the RbOH solution is flown in one channel and deionized water (DIW) or eluent flows in the other channel. By connecting the (+) electrode and the (-) electrode to each channel, the current air gap control unit 160, that is, a device for finely controlling the current, for example, using a programmable current source 220 model (Keithely, USA), A certain amount of current is applied to produce H ⁺ in the channel filled with the RbOH solution and OH ^- in the eluent channel. In the RbOH channel where H ⁺ is generated to maintain the electrical neutral state, Rb ⁺ moves to the eluent channel through the cation exchange membrane 133 and is electrically negative due to OH ⁻ generated in the eluent channel. ⁺ Cation exchange membrane 133 is promoted through the phenomenon. As a result, a certain amount of RbOH solution is added to the eluent channel. In the test analysis using the on-line automatic modification device of the suppressor type ion chromatography eluent of the present invention, a current of 0.804 μA was applied to allow constant addition of about 0.50 μM Rb ⁺ to the eluent when using a flow rate of 1.0 mL/min. At this time, the background conductivity is about 162 nS/cm, and the noise of the background line is 0.050 nS/cm.

4 is a cross-sectional view showing an on-line automatic deforming device of a suppressor type ion chromatography eluent according to a second embodiment of the present invention.

Referring to FIG. 4, the on-line automatic transformation device 200 of the suppressor type ion chromatography eluent according to the second embodiment of the present invention, on-line automatic conversion of the suppressor type ion chromatography eluent according to the first embodiment, As in the deforming apparatus 100, a supply path 213 is formed to supply deionized water or eluent to the ion exchange space portion 211 provided on one side, and cations or anions are added in the ion exchange space portion 211 It is provided in the body 210 to be connected to the ion exchange space portion 211, the main body 210 is formed with a discharge path 215 to discharge the deionized water or eluent to the outside, for the addition of positive or negative ions The storage tank 220 in which the electrolyte solution is stored, and the ion exchange unit for separating the supply path 213 side and the storage tank 220 side to the ion exchange space 211 so that only one of positive and negative ions passes through it. (230), with the ion exchange unit 230 interposed therebetween, is installed on the supply path 213 side and the storage tank 220 side, and positive or negative ions provided from the electrolyte solution are provided to the supply path 213 side. The first and second electrodes 240 and 250 for supplying the anode current and the cathode current, respectively, and a current supply control unit (not shown) for adjusting the current supplied to the first and second electrodes 240 and 250, respectively, may be included. In addition, in the main body 210, the hermetic cap 212 may be installed as in the previous embodiment, and the exhaust port 221 may be formed in the storage tank 220, and the ion exchange unit 230 may include frits and cations. It may include an exchange sheet, a cation exchange membrane and a cation exchange tube. In addition, the first electrode 240 may be provided with a coil portion 241 and a first connector (not shown). The second electrode 240 may be provided with a Pt ribbon 251 and a second connector (not shown). Therefore, the on-line automatic transformation device 200 of the suppressor type ion chromatography eluent according to the second embodiment of the present invention is an on-line automatic transformation device of the suppressor type ion chromatography eluent according to the previous embodiment. Except for the difference between (100) and the following, it has the same configuration, and the same configuration has already been described in detail in the previous embodiment, so the description will be omitted.

In addition, the on-line automatic transformation device 200 of the suppressor type ion chromatography eluent according to the second embodiment of the present invention may be configured as a system for cations as in the previous embodiment, or alternatively, as a system for anions. Since this has already been described in the previous embodiment, the description will be omitted.

In addition, the on-line automatic transformation device 200 of the suppressor type ion chromatography eluent according to the second embodiment of the present invention, unlike the previous embodiment, the supply path 213 has a diameter on the side where deionized water or eluent is supplied. The first extension tube 235 to be connected may be connected, and a second extension tube 236 whose diameter is expanded may be connected to a side where the deionized water to which ions are added or eluent is discharged.

The operation principle of the on-line automatic transformation device 200 of the suppressor type ion chromatography eluent of this embodiment is the same as the operation principle of the on-line automatic transformation device 100 of the suppressor type ion chromatography eluent of the first embodiment. The difference in structural aspect is that in this embodiment, the dead volume is reduced by using a 1/32 inch capillary tubing and a 1/16 inch fitting in the flow path where the solution enters and exits, thereby reducing peak expansion. It was mitigated to secure the accuracy of the analysis.

5 is a block diagram showing an ion chromatography system having an on-line automatic deformation device for eluents according to a first embodiment of the present invention.

Referring to FIG. 5, the ion chromatography system 300 having an on-line automatic transformation device for eluent according to the first embodiment of the present invention includes a storage container 303 in which deionized water is stored and a pump from the storage container 303 An ion trap column 304 for removing impurities of anions or cations present in the deionized water transported by the 302, and an eluent maker 305 for producing deionized water passing through the ion trap column 304 as an eluent , Analysis to remove the gas inside the eluent manufactured by the eluent maker 305 and the sample injected by the injection valve 308 to be separated by the eluent passing through the degasser 306 The column 309, the suppressor 310 for removing ions having opposite polarities of the ions to be detected contained in the eluent passing through the analysis column 309, and the ions to be analyzed in the sample passing through the suppressor 310 It may include an electrical conductivity detector 311 for performing a quantitative analysis through the measurement of the electrical conductivity of the, furthermore, on-line automatic of the suppressor type ion chromatography eluent to add a defined concentration of cations or anions to deionized water or eluent Deformation device may be included.

In the present embodiment, the on-line automatic deforming device of the suppressor type ion chromatography eluent is the on-line automatic deforming device 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention, or the second embodiment of the present invention According to the suppressor type ion chromatography may be an online automatic transformation device 200 of the eluent, it may be installed between the ion trap column 304 and the eluent maker 305. In addition, a helium supply unit 301 to supply helium to the storage container 303 may be installed. A mixer 307 for mixing so that the ion concentration of the eluent is uniform may be installed at the rear end of the degueser 306. In addition, the suppressor 310 may be operated in a recycling mode in which a solution discharged to the outside is circulated.

As shown in FIG. 6, in this embodiment, the ion chromatography system 300 is located at the rear end of the ion trap column 304 and is manufactured to withstand high pressure, and the suppressor type ion according to the first embodiment of the present invention It adds an online automatic transformation device for chromatographic eluent. Deionized water moves through the pump 302, and anion impurities in distilled water are completely removed from the ion trap column 304. About 0.5 μM Rb ⁺ is added to the distilled water while the anion-removed distilled water is passed through an on-line automatic modification of the suppressor type ion chromatography eluent according to the present invention. 0.5 μM Rb ⁺ distilled water containing the phosphorus eluent making machine automatically producing system commercialized eluant is changed as an eluent containing 0.5 μM Rb ⁺ as it passes through the (a device for automatically generating an MSA solution to a predetermined concentration) (Eluent generator 305). The automatically prepared eluent is degassed inside the eluent while passing through the degasser 306, and the concentration of the eluent is uniformly mixed while passing through the mixer 307. When a sample is injected into the injection valve 308 and injection is performed, the cation sample enters the analysis column 309 and is separated by the eluent. A suppressor 310 which is a pre-treatment device for detection that reduces the electrical conductivity of the eluent and improves the S/N ratio by removing ions having a polarity opposite to a target ion contained in the eluent eluting from the analysis column 309 In the sample, the anion in the sample is exchanged for OH ^- . At this time, in a general ion chromatography system, the eluent is converted to water, and when low concentration analysis is performed, a non-linear reduction problem occurs in a small amount analysis due to a sponge phenomenon caused by automatic ionization of water. However, in the present invention suppress the standing frame rewritable type ion chromatographic eluent of water dissociation because Rb ⁺ to the cationic impurities present in the even through the suppressor 310 in the present system configuration through the online automatic transformation apparatus of the eluent Eluent, It solves the problem of deterioration of nonlinear sensitivity due to the sponge phenomenon. Finally, the sample is quantitatively analyzed by measuring the electrical conductivity of each analyte ion in the cell of the electrical conductivity detector 311.

6 is a block diagram showing an ion chromatography system having an on-line automatic deformation device for eluents according to a second embodiment of the present invention.

Referring to FIG. 6, the ion chromatography system 400 having an on-line automatic modification device of the eluent according to the second embodiment of the present invention includes a storage container 403 in which deionized water is stored and a pump from the storage container 403 An ion trap column 404 for removing impurities of anions or cations present in deionized water transported by the 402, and an eluent maker 405 for producing deionized water that has passed through the ion trap column 404 as an eluent. , Analysis to remove the gas inside the eluent manufactured by the eluent maker 405 and the sample injected by the injection valve 408 to be separated by the eluent passing through the degasser 406 The column 409, the suppressor 410 for removing ions having opposite polarities of the ions to be detected contained in the eluent passing through the analysis column 409, and the ions to be analyzed in the sample passing through the suppressor 410 It may include an electrical conductivity detector (411) for performing a quantitative analysis through the measurement of the electrical conductivity of the, furthermore, on-line automatic of the suppressor type ion chromatography eluent to add a specified concentration of cations or anions to deionized water or eluent Deformation device may be included.

In the present embodiment, the on-line automatic deforming device of the suppressor type ion chromatography eluent is the on-line automatic deforming device 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention, or the second embodiment of the present invention The suppressor-type ion chromatography may be an on-line automatic transformation device 200 of the eluent, and may be installed between the ion trap column 404 and the eluent maker 405.

In this embodiment, the suppressor 410 may be operated in an external supply mode that supplies clean distilled water from which foreign substances such as anions and cations have been removed by the foreign substance removal column 412, and is identical to all of the following examples. Can be applied. This is a connection mode of a general ion chromatography system, and it is known that such an external mode analysis optimizes the analysis conditions by lowering the background conductivity value of the ion chromatography. The foreign material removal column 412 may be supplied with nitrogen gas as a purge gas from the purge gas supply unit 413.

7 is a block diagram showing an ion chromatography system having an on-line automatic deformation device for eluent according to a third embodiment of the present invention.

Referring to FIG. 7, the ion chromatography system 500 having an on-line automatic modification device of an eluent according to a third embodiment of the present invention is an ion chromatography having an on-line automatic modification device of an eluent according to the second embodiment of the present invention. It has the same configuration as the graphing system 400, but an on-line automatic transformation device of the suppressor type ion chromatography eluent can be installed between the analysis column 409 and the suppressor 410, where the suppressor type ion chromatography is used. On-line automatic transformation device of the eluent for graphography is an on-line automatic transformation device 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention, or a suppressor type ion chromatography eluent according to the second embodiment of the present invention On-line automatic transformation device 200 may be.

8 is a block diagram showing an ion chromatography system having an on-line automatic deformation device for eluents according to a fourth embodiment of the present invention.

Referring to FIG. 8, the ion chromatography system 600 having an on-line automatic modification device of an eluent according to a fourth embodiment of the present invention is an ion chromatography having an on-line automatic modification device of an eluent according to the second embodiment of the present invention. It has the same configuration as the graphing system 400, but an on-line automatic transformation device of a suppressor type ion chromatography eluent can be installed between the suppressor 410 and the electrical conductivity detector 411, where the suppressor type ion The on-line automatic modification device of the chromatographic eluent is the suppressor type ion chromatography on-line automatic modification device 100 according to the first embodiment of the present invention, or the suppressor type ion chromatography according to the second embodiment of the present invention It may be an on-line automatic transformation device 200 of the eluent.

The configuration principle of the ion chromatography system 400,500,600 of the embodiment corresponding to FIGS. 6 to 8 is the same as the description of the ion chromatography system 300 of the embodiment corresponding to FIG. 5, however, the manual according to the present invention The mounting location can be varied to determine where the on-line automatic deformer of the presser type ion chromatography eluent can ensure the accuracy of the method.

The operation of the on-line automatic transformation device of the suppressor type ion chromatography eluent according to the present invention and the ion chromatography system having the same will be described.

Figure 9 shows the principle of operation for the cation system of the automatic on-line deformer of the suppressor type ion chromatography eluent according to the present invention.

Referring to FIG. 9, a cation exchange membrane is placed as an interface, and an RbOH solution is flowed in one channel and deionized water (DIW) or eluent is flowed in the other channel. By connecting (+) electrode and (-) electrode to each channel, a certain amount of current is applied to produce H ⁺ in the channel filled with RbOH solution and OH ^- in the eluent channel. In RbOH channel of the H ⁺ generated in order to maintain the electrically neutral state, and the Rb ⁺ moves to the eluent channel through the cation exchange membrane, the OH generated in the eluent ^channel, electrically tinged voice due to, for these Rb ⁺ The phenomenon of passing through the cation exchange membrane is promoted. As a result, a certain amount of RbOH solution is added to the eluent channel. In the case of an on-line automatic modification of the suppressor type ion chromatography eluent for anion system, anion exchange membrane and P-toluenesulfonic acid solution are used instead of cation exchange membrane and RbOH solution.

When the on-line automatic transformation device of the suppressor type ion chromatography eluent is used, not only can the eluent containing a certain amount of impurities be prepared on-line, but also because the eluent is prepared immediately before flowing into the column. By minimizing the contamination of the carbonate, the background conductivity is sufficiently lowered to facilitate the analysis of trace inorganic ions at the ng/L level, and an eluent concentration gradient program can be applied.

The ion-exchange membrane is composed of ions to be substituted in the basic polymer matrix and ionic functional groups with electrostatic attraction. In other words, in the case of a cation exchange membrane, a functional group having a negative charge is fixed, and a functional group of a positive charge is fixed in the anion exchange membrane. Due to this, ions having a charge such as a functional group cannot pass through the ion exchange membrane due to the electrostatic repulsive force, and the imaginary membrane generated by this charge distribution is referred to as a stolen membrane.

This is called Donan exclusion, and when the difference in ion concentration at the ion exchange membrane interface is very large, the exclusion phenomenon caused by this stolen membrane does not occur completely. In particular, when the solution to which the ionic species migrated is pure water, the osmotic pressure becomes a level that can sufficiently overcome the stolen potential. Despite the fact that the current is not applied, the degree to which a significant amount of ions is added as an eluent is called Donan-forbidden leakage, and thus, in the present invention, when devising an online automatic deforming device for a suppressor type ion chromatography eluent in the present invention, , The concentration of the RbOH solution and the area in contact with the eluent should be first considered, and thus, such a nonnan-forbidden leakage should be minimized.

As shown in Figure 3, the on-line automatic deformation apparatus 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention is an ion chromatography system used in this experiment is ICS-5000 (Dionex, Sunnyvale, CA , USA). Table 1 shows the experimental conditions for the ion chromatography system using the on-line automatic modification device of the suppressor type ion chromatography eluent according to the first embodiment of the present invention. In addition, in the present invention, a programmable current source 220 model (Keithely, USA) was used as a device for finely controlling the current applied to the online automatic deformation device of the suppressor type ion chromatography eluent.

Analytical system ICS-5000(Dionex) Analytical column IonPac CS14 (4 X 250 mm, Dionex) Eluent MSA 8 mM Eluent flow rate 1.00 mL/min Injection volume 5 μL Suppressor CAES(Dionex) Suppressor current 26 mA Data collection software Chromeleon 7.0 (Dionex)

The on-line automatic transformation device 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention is developed by optimizing in a unique condition by connecting it between the pump 302 and the eluent maker 305. When applied to gradient), the problem arises that the baseline is shaken and the equilibrium arrival time for the next analysis is prolonged. In order to solve this, the on-line automatic transformation device of the suppressor type ion chromatography eluent must be mounted behind the ion trap column 304, on-line automatic transformation device of the suppressor type ion chromatography eluent according to the second embodiment of the present invention ( 200) reduced or suppressed the occurrence of peak spread due to large void volume.

Prior to analyzing low concentration inorganic ions using the online automatic strainer 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention, current is not applied due to nnan-forbbiden leakage. Even if it was confirmed that the RbOH solution is added as an eluent, the results are shown in Table 2 below. As shown in Table 2, the same as the base conductivity value of 78 nS/cm, in which the online automatic deforming device 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention is not included, It was confirmed that the on-line automatic deforming device 100 of the suppressor type ion chromatography eluent according to the first embodiment of the invention was mounted, and the background conductivity value without applying a current was detected to be 78 nS/cm. In addition, the eluent was analyzed using a separate ion chromatography system that passed through the detector, and it was confirmed that the concentration of Rb ⁺ was very low below the detection limit and was not detected. Therefore, it can be seen that the phenomenon in which the RbOH solution is added as the eluent does not appear due to the stolen leak (donnan-leakage) in the online automatic deformer 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention. . Table 2 below shows the change in the degree and background conductivity of the donnan-leakage according to the concentration of the RbOH solution in the on-line automatic deformation apparatus 100 of the suppressor type ion chromatography eluent according to the first embodiment of the present invention.

Reservoir RbOH Concentration ( mM ) 40 100 Background conductivity ( μS /cm) 0.078 0.078 Rb ⁺ concentration in effluent ( μM ) n.d. n.d. Total conductivity calculated with effluent RbOH ( μS /cm) 0.078 0.078

-n.d. ; not detected

-The background conductivity value in the absence of an on-line automatic deformation device of the suppressor type ion chromatography eluent is 0.078 μS/cm

FIG. 10 shows a background conductivity value of a cationic chromatography system for 41 hours with a current of 804 nA applied to the online automatic strainer 100 of a suppressor type ion chromatography eluent according to a first embodiment of the present invention for 1 hour. This is the result of monitoring at intervals. At this time, the average of the background conductivity value is 165 nS/cm, and the relative standard deviation (RSD) is 0.57%, showing a very small value, and it can be confirmed that a constant concentration of RbOH is stably added as an eluent.

Table 3 compares the theoretically calculated value of the background conductivity which increases with the concentration of RbOH added to the eluent, and the online automatic modification device of the suppressor type ion chromatography eluent according to the first embodiment of the present invention (100) ) Is used to compare the value of the increased background conductivity and calculate the efficiency of adding RbOH according to the current intensity and the concentration of the RbOH solution contained in the storage tank 120. It can be seen that the higher the concentration of RbOH in the storage tank 120 and the stronger the applied current, the higher the efficiency of adding RbOH.

RbOH generation efficiency ( % ) RbOH
Concentration [ mM ] 40.0 100 Current [ μA ] 2.00 63.30 67.66 4.00 74.48 78.84 6.00 81.30 81.30 8.00 84.57 85.22 10.0 85.83 86.88

FIG. 11 shows a change in background conductivity according to the intensity and time of the current in the online automatic deformation apparatus 100 of a suppressor type ion chromatography eluent according to the first embodiment of the present invention. The current of 0~10 μA was gradually added and subtracted at 1 hour intervals, and the background conductivity value was monitored accordingly. It can be seen that there is no synergistic effect of background conductivity due to Donan-forbbiden leakage, and it can be seen that the efficiency of adding RbOH is high at about 68% even under a very low current of 2 μA. In addition, it was confirmed that when 10 μA of current was applied, it took about 5 minutes to reach 90% of the theoretical background conductivity increase value, and the response speed was fast enough, so that there was no problem in the use of trace inorganic ion analysis.

Table 4 and Table 5 is a cationic chromatography system in which 0.5 μM Rb ⁺ is added to the eluent by applying an on-line automatic modification device of a suppressor type ion chromatography eluent according to a first embodiment of the present invention and a general cationic chromatography system. It is a result of evaluating the precision by repeatedly analyzing the low-concentration cation assay reagent for 3 days at 1 hour intervals. Accuracy (RSD) in a system using an eluent containing a constant concentration of Rb ⁺ using an online automatic strainer of a suppressor type ion chromatography eluent according to a first embodiment of the present invention through intraday and interday precision evaluation is 6 It can be seen that it is secured very low to 2% or less for the dog's ionic species. In addition, it was confirmed that the accuracy (recovery) compared to the theoretical value of the analytical peak is secured within 3% for the six ionic species, and the on-line automatic modification device of the suppressor type ion chromatography eluent according to the present invention was applied to remove impurities online. It was confirmed that it can be added to solve the nonlinear response problem.

Precision evaluation of the system for applying the on-line automatic deformation device of the suppressor type ion chromatography eluent according to the first embodiment of the present invention (Intraday) C
( μmol /L)
peak concentration( μmol /L) One 2 3 Meam ±SD (μmol/L) RSD ( % ) Recovery( % ) Li ⁺
0.36
0 μM Rb ⁺ 0.4010 0.4010 0.3366 0.3795 ± 0.0372 9.81 92.3 0.5μM Rb ⁺ 0.3653 0.3694 0.3663 0.3670 ± 0.0021 0.57 103.2 Na ⁺
0.43
0 μM Rb ⁺ 0.4952 0.4832 0.4277 0.4687 ± 0.0360 7.68 105.7 0.5μM Rb ⁺ 0.4328 0.4331 0.4340 0.4333 ± 0.0007 0.15 100.8 NH ₄ ⁺
0.69
0 μM Rb ⁺ 0.7020 0.8022 0.7421 0.7488 ± 0.0505 6.74 100.4 0.5μM Rb ⁺ 0.7176 0.7159 0.7210 0.7182 ± 0.0026 0.36 102.5 K ⁺
0.64
0 μM Rb ⁺ 0.9549 0.8437 0.6881 0.8289 ± 0.1340 16.2 103.7 0.5μM Rb ⁺ 0.6357 0.6321 0.6457 0.6379 ± 0.0070 1.10 99.7 Mg ^{2 +}
0.51
0 μM Rb ⁺ 0.6890 0.6890 0.9355 0.8289 ± 0.1340 16.2 130.2 0.5μM Rb ⁺ 0.6099 0.4832 0.4963 0.6379 ± 0.0070 1.10 103.3 Ca ^{2 +}
0.62
0 μM Rb ⁺ 0.8588 0.7525 0.9088 0.8401 ± 0.0798 9.50 148.3 0.5μM Rb ⁺ 0.6227 0.6227 0.6043 0.6166 ± 0.0106 1.73 100.9

Accuracy evaluation of the system for applying on-line automatic deformation device of the suppressor type ion chromatography eluent according to the first embodiment of the present invention (Interday) C
( μmol /L)
peak concentration( μmol /L) One 2 3 Meam ±SD ( μmol /L) RSD ( % ) Recovery(%) Li ⁺
0.36
0 μM Rb ⁺ 0.2829 0.3454 0.3688 0.3324 ± 0.0444 13.4 105.4 0.5μM Rb ⁺ 0.3719 0.3754 0.3675 0.3716 ± 0.0040 1.1 101.9 Na ⁺
0.43
0 μM Rb ⁺ 0.4335 0.4686 0.4612 0.4544 ± 0.0185 4.1 109.0 0.5μM Rb ⁺ 0.4365 0.4311 0.4324 0.4333 ± 0.0028 0.65 100.8 NH ₄ ⁺
0.69
0 μM Rb ⁺ 0.6540 0.6684 0.7554 0.6926 ± 0.0549 7.9 108.5 0.5μM Rb ⁺ 0.7049 0.7002 0.7169 0.7073 ± 0.0086 1.2 104.1 K ⁺
0.64
0 μM Rb ⁺ 0.6816 0.5966 0.7131 0.6638 ± 0.0602 9.1 129.5 0.5μM Rb ⁺ 0.6460 0.6604 0.6392 0.6486 ± 0.0108 1.67 101.3 Mg ^{2 +}
0.51
0 μM Rb ⁺ 0.6816 0.5966 0.7131 0.6638 ± 0.0602 9.1 162.5 0.5μM Rb ⁺ 0.5315 0.5256 0.5227 0.5266 ± 0.0044 0.84 125.1 Ca ^{2 +}
0.62
0 μM Rb ⁺ 0.9698 0.9849 0.8036 0.9194 ± 0.1006 10.9 135.5 0.5μM Rb ⁺ 0.6316 0.6258 0.6188 0.6254 ± 0.0064 1.0 99.4

As a result of experiments in various arrangements of the cationic ion chromatography system, the online automatic deforming device 200 of the suppressor type ion chromatography eluent according to the second embodiment of the present invention was tested, and when it was mounted behind a column, baseline drift in a gradient condition analysis due to drift). When mounted between the column and the suppressor, a baseline drift of about 13.5 uS/cm occurred in the gradient condition. It is estimated that the membrane impurities of the online automatic deforming device 200 of the suppressor type ion chromatography eluent according to the second embodiment of the present invention are eluted by the cationic eluent MSA, and the baseline drifts over time. The degree of (baseline drift) decreased, but it was judged to be difficult to apply to the analysis. As a result of the experiment by mounting the on-line automatic deformation apparatus 200 of the suppressor type ion chromatography eluent according to the second embodiment of the present invention after the suppressor with different arrangements, the background conductivity value in the gradient condition is 0.2 uS/cm, Noise was maintained at normal conditions with 0.1 nS/cm, and baseline drift was 4 nS/cm, which was not a problem for analysis. In addition, compared to the case where the on-line automatic deforming device 200 of the suppressor type ion chromatography eluent according to the second embodiment of the present invention is not mounted, the peak area increased by an average of 6 times or more. 12 is a cation analysis chromatogram of gradient conditions when an on-line automatic modification device of a suppressor type ion chromatography eluent according to a second embodiment of the present invention is mounted behind a suppressor.

In the present invention, the non-linear sensitization problem was solved by suppressing the automatic ionization equilibrium movement of water by constantly adding a low concentration of impurity ions into the eluent. FIG. 13 shows a 0.1 μmol/L Li ⁺ ion analysis peak when a senic acid eluent containing 0.5 μmol/L dipropylamine is used, and an analysis peak having a size close to an outlier is detected by suppressing a decrease in background conductivity. Can be confirmed.

Although the present invention has been described with reference to the accompanying drawings, various modifications and variations can be made without departing from the technical spirit of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims described below, but also by the claims and equivalents.

110,210: main body 111,211: ion exchange space
112,212: airtight cap 113,213; Supply path
114: supply port 115,215: discharge path
116: discharge port 120,220: storage tank
121,221: exhaust port 130,230: ion exchange unit
131: frit 132,232: cation exchange sheet
133,233: cation exchange membrane 134,234: cation exchange tube
140,240: first electrode 141,241: coil part
142: first connector 150,250: second electrode
151,251: Pt ribbon 152; 2nd connector
160: current supply control unit 235: first extension tube
236: second extension tube 301: helium supply
302,402: Pump 303,403: Storage container
304,404: Ion trap column 305,405: Eluent maker
306,406: Dicer 307: Mixer
308,408: Injection valve 309,409: Analysis column
310,410: suppressor 311,411: electrical conductivity detector
412: foreign matter removal column 413: purge gas supply unit

Claims (11)

A device for supplying positive or negative ions to the eluent of an ion chromatography system,
A supply path is formed to supply deionized water or eluent to the ion exchange space provided on one side, and a discharge path is formed to discharge deionized water or eluent to which cation or anion is added from the ion exchange space to the outside. main body;
A storage tank provided in the main body to be connected to the ion exchange space, and storing an electrolyte solution for adding the cations or anions;
An ion exchange unit separating the supply path side and the storage tank side in the ion exchange space to pass only one of positive and negative ions;
The first and the positive electrode current and the negative electrode current are respectively provided on the supply path side and the storage tank side, and the positive or negative currents provided from the electrolyte solution are provided to the supply path side with the ion exchange part interposed therebetween. A second electrode; And
A current supply control unit for adjusting the current supplied to the first and second electrodes;
Including,
The first electrode,
It is made of Pt wire which is installed to extend to the end of the supply path through the main body, and a coil part is provided at the end,
The second electrode,
Made of Pt wire installed to extend to the entrance side of the storage tank, a Pt ribbon is provided to increase the area at the end,
The supply path,
A first extension tube having an expanded diameter is connected to a side to which the deionized water or eluent is supplied,
The discharge path,
A second extension tube having an expanded diameter is connected to the side where the ion-added deionized water or the eluent is discharged,
The ion exchange unit,
A plurality of frits are provided to be spaced apart from each other in the ion exchange space part, an anion exchange sheet is stacked between the frits, an anion exchange membrane is interposed between the anion exchange sheets, and an entrance side of the ion exchange space part is provided. In the anion exchange tube is installed to suppress the separation of the frit,
The storage tank,
The electrolyte solution is P-TSA (para Toluenesulfonic acid),
The first electrode,
It is an anode electrode installed on the supply path side,
The second electrode
On-line automatic deformation device of a suppressor type ion chromatography eluent, which is a cathode electrode installed on the storage tank side. delete delete delete delete A storage container in which deionized water is stored;
An ion trap column for removing impurities of anions or cations present in deionized water transferred by the pump from the storage container;
An eluent maker for preparing deionized water that has passed through the ion trap column as an eluent;
A degasser for removing gas inside the eluent produced by the eluent maker;
An analysis column that separates the sample injected by the injection valve by the eluent that has passed through the degasser;
A suppressor to remove ions having opposite polarities of ions to be detected contained in the eluent that has passed through the analysis column; And
An electrical conductivity detector that performs quantitative analysis by measuring the electrical conductivity of the ions to be analyzed in the sample that has passed through the suppressor;
Including,
On-line automatic deformation apparatus of the suppressor type ion chromatography eluent according to claim 1,
Adding a defined concentration of cations or anions to deionized water or eluent,
The suppressor,
An ion chromatography system having an on-line automatic modification of the eluent, which is operated in an external supply mode that supplies clean distilled water from which foreign matter has been removed by a foreign matter removal column. The method according to claim 6,
On-line automatic transformation device of the suppressor type ion chromatography eluent,
An ion chromatography system having an on-line automatic deformation device for the eluent, which is installed between the ion trap column and the eluent maker. The method according to claim 6,
On-line automatic transformation device of the suppressor type ion chromatography eluent,
An ion chromatography system having an on-line automatic transformation device for eluent, which is installed between the analysis column and the suppressor. The method according to claim 6,
On-line automatic transformation device of the suppressor type ion chromatography eluent,
An ion chromatography system having an on-line automatic deformation device for eluent, which is installed between the suppressor and the electrical conductivity detector. delete delete

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