KR100265024B1 - Electrochemical testing systen using a mercury electrode system - Google Patents

Abstract

PURPOSE: A microelement measuring system by using a mercury dropping electrode is provided to secure a precise amount of mercury drops in a groove formed at an upper part of a capillary and omit the necessity of substituting an electrode with a new one even in case of inspection of pollutant of high concentration. CONSTITUTION: A microelement measuring system by using a mercury dropping electrode includes a second switch valve(120) for selectively opening a pure water case(100), an electrolyte case(102) and a sample case(104) according to a set position of a second tube(122) to supply liquid via a connection line(124), a second micro syringe(220) for supplying the liquid introduced via the connection line to a first line(L1) connected to the second switch valve by the operation of a second motor(226), a third switch valve(130) located at a first set position for supplying the liquid to a second line(L2), a second set position for alternatively supplying nitrogen gas introduced from a nitrogen case(160) to the second line or a fourth line(L4), or a third set position for opening or closing flow channels, a fourth switch valve(140) for supplying the liquid introduced via the second line to a cell(12) via a third line(L3), a fifth switch valve(150) for supplying a standard sample introduced from a standard sample container(180) to a fifth line(L5), a third micro syringe(230) for inhaling the standard sample introduced from the fifth line to supply to the cell via a sixth line(L6) and the fourth switch valve, and a recovery case(178) for introducing the fluid discharged from the fourth switch valve via an eighth line(L8) and introducing the solution and mercury in the cell via a ninth line(L9).

Description

Trace element measuring system using red mercury electrode

The present invention relates to a trace element measuring system using a dropping mercury electrode, and in particular, a simple flow path using a plurality of switch valves, and at the same time using a precision injector to the correct amount of electrolyte and sample and sample solution in the cell The present invention relates to a trace element measuring system using a dropping mercury electrode capable of accurately performing quantitative qualitative analysis of trace elements even without a specialist.

Polarography, which is commonly used for quantitative qualitative analysis of various trace components, uses the principle that voltage-current characteristics are proportional to the type and concentration of analyte. That is, in polarography, the current flowing through the cell is measured as a function of the potential (voltage) of the dropping mercury working electrode formed at the capillary end of the height-adjustable mercury storage container, and the trace component is analyzed by the relationship between the measured voltage and the current. Done.

In particular, in the case of using a fixed electrode such as platinum as a working electrode in graphy, the mercury electrode is mainly used because the potential of the working electrode varies depending on the surface state of the electrode. The use of mercury electrodes results in more reproducible voltage-current characteristics than those using fixed surfaces, since mercury droplets grow in size, creating new surfaces continuously and exposing them to the analyte.

1 is a schematic view showing a part of a conventional dropping mercury electrode system. As shown here, the conventional dropping mercury electrode system has a structure in which mercury in the mercury storage container 1 containing mercury is dropped into the cell 8 as the opening / closing valve 3 is opened. The reference electrode 5 and the platinum auxiliary electrode 6 are provided inside the cell 8 in which the sample solution is contained.

Here, the mercury storage container (1) is configured to adjust the height to control the drop rate of the mercury drop, the on-off valve (3) to adjust the opening and closing time to ensure that the appropriate size of the mercury drops hanging on the capillary bottom It is configured to be.

As described above, the conventional dropping mercury electrode using the capillary phenomenon has a problem in that the mercury column is frequently broken by the impact. When the measurement is carried out while the mercury drop is suspended at the end of the capillary tube, the mercury drop drops due to the impact or other causes. In particular, during the reduction reaction, the contamination inside the capillary proceeds, and mercury droplets do not hang at the end of the capillary tube and often fall off, and thus cannot be stably measured. In addition, the size of the mercury electrode, which is the most important variable in the measurement, changes greatly every time the electrode is produced, making accurate measurement difficult.

In particular, in the case of measuring the water pollution, etc., a method using a dropping mercury electrode as in the conventional method takes a lot of time, and in addition to the fact that it is almost impossible to install an analyzer in the field, there is a problem of low accuracy of the measured value.

In order to solve the above problems, the present invention provides a simple configuration of a flow path using a plurality of switch valves, and by measuring and supplying an accurate amount of electrolyte and a sample and a sample solution to a cell using a precision injector, The purpose of the present invention is to provide a trace element measurement system using a suitable mercury electrode having a structure capable of accurately performing a quantitative qualitative analysis of trace elements even without a professional manpower and easily replacing a standard sample.

1 is a configuration diagram showing a part of a conventional dropping mercury electrode system,

Figure 2 is a block diagram showing a trace element measuring system using a red mercury electrode according to the present invention.

♣ Explanation of symbols for main part of drawing ♣

12: Cell 22: Agitator

24: Fan 30: Capillary tube

40: first switch valve 46: first pipe

48: platinum 50: mercury storage container

40, 120, 130, 140, 150: first to fifth switch valves

46, 126, 136, 146, 156: First to fifth pipe 178: Recovery container

180: Standard sample container L1 to L9: Lines 1 to 9

The object of the present invention described above is a cell having a capillary tube on which a reference electrode and an auxiliary electrode and a mercury is placed on the upper side, a first switch valve for selectively supplying mercury flowing from a mercury storage container through a supply tube into a capillary tube, and A dropping mercury electrode comprising a first precision injector for supplying mercury sucked through a first pipe line mounted on a first switch valve by operation of a motor to a capillary tube, the pure passage electrolyte depending on the setting position of the second pipe line. A second switch valve for selectively opening the container and the sample container so that the liquid contained therein is supplied to the connection line, and the first liquid connected to the second switch valve by the operation of the second motor. The second precision injector for supplying the line and the nitrogen gas cylinder through the first preset position and the seventh line for supplying the liquid introduced into the first line to the second line. A third switch valve having a third conduit for opening and closing the flow path at any one of a second set position and a third set position for selectively supplying nitrogen gas introduced from the second line and the fourth line; A fourth switch valve for supplying the liquid introduced through the second line to the cell through the third line according to the set position of the conduit, and the standard sample introduced from the standard sample container according to the set position of the fifth conduit to the fifth line. A third precision injector for supplying the fifth switch valve to be supplied, the standard sample introduced through the fifth line under the control of the third motor, and then supplying it to the cell via the sixth and fourth switch valves; and a vacuum pump. According to the set position of the fourth conduit by the operation of the fluid discharged from the fourth switch valve through the eighth line, the solution and mercury in the cell is provided with a recovery vessel through the ninth line It is achieved by a trace element measuring system using a dropping mercury electrode, characterized in that.

Hereinafter, with reference to the accompanying Figure 2 will be described in detail with respect to the trace element measuring system using a dropping mercury electrode according to a preferred embodiment of the present invention.

Figure 2 is a block diagram showing a trace element measuring system using a red mercury electrode according to the present invention. Instead of a conventional dropping mercury electrode that causes mercury to hang at the capillary end using gravity, in a preferred embodiment of the present invention, mercury is mounted on top of the capillary 30 detachably mounted to the pedestal 10 of the cell 12. Trace elements were measured using a dropwise mercury electrode of the push-up method.

When the mercury electrode is accumulated, the cell 12 containing the sample solution and the pedestal 10 holding the cell 12, the capillary 30 installed on the pedestal 10 by screwing, and the capillary tube ( The stirrer 22 for removing the mercury droplet 52 fixed to the upper seating groove 30a of the 30 and the mercury introduced through the supply pipe 54 from the mercury storage container 50 storing mercury accurately Selective communication between the first precision injector 60 and the supply pipe 54, the first precision injector 60, and the capillary tube 30 according to the set position of the first pipe line 46 and the metering and supplying the capillary tube 30. It is composed of a first switch valve 40 for controlling the supply of mercury.

The reference electrode 16 and the auxiliary electrode 18 are provided inside the cell 12, and a cover 14 is covered on the upper side thereof. The upper part of the cell 12 is provided with a stirrer 22 for removing the mercury droplet 52 seated on the upper portion of the capillary tube 30. The agitator 22 has a motor 20 built in, and the rotation of the motor 20 is transmitted to the fan 24 through the shaft 26. When the mercury is removed after the measurement is completed, the shaft 26 is lowered so that the fan 24 is positioned upwardly adjacent to the mercury droplet 52 and then rotated to remove the mercury.

Mercury stored in the mercury storage container 50 is introduced into the first precision injector 60 through the first switch valve 40 by the control of the first motor 66 and then supplied to the capillary tube 30. . On the outer circumferential portion of the switch valve 40, a plurality of ports 41 to 44 through which mercury is introduced and discharged are radially formed. In the center of the first pipe line 46, platinum 48 which maintains contact with mercury is formed. It is fitted. The working electrode 70 is connected to the platinum 48, and the opening and closing valve 56 is installed in the supply pipe 54 for supplying mercury to the first switch valve 40.

In the schematic configuration of the trace element measuring system of the present invention using the dropwise mercury electrode having such a configuration, the liquid contained in the pure water container 100, the electrolyte container 102 and the sample 104 is connected to the connection line 124. The second switch valve 120 to be sent to the second precision injector 220 through the third switch valve 130 for supplying the liquid supplied through the second switch valve 120 to the second line (L2) and A fourth switch valve for supplying the liquid supplied through the second line L2 to the cell 12 or for supplying the nitrogen gas supplied from the nitrogen gas cylinder 160 to the recovery vessel 178 through the eighth line L8. And a fifth switch valve 150 for supplying the standard sample contained in the standard sample container 180 to the third precision injector 230 through the fifth line L5. 230 supplies a standard sample introduced from the fifth switch valve 150 to the cell 12 through the fourth switch valve 140. The.

Here, the second switch valve 120 is provided with a second pipe line 122 connected to the second precision injector 220 through the connection line 124. The second pipe line 122 selectively opens the pure water container 100, the electrolyte container 102, and the sample container 104 according to the set position, and supplies the pure water, the electrolyte, and the sample contained in each container to the second precision injector. (220).

In the second precision injector 220, a piston 222 operatively connected to the second motor 226 through the piston rod 224 is mounted to slide. Therefore, when the piston 222 is lowered by the operation of the second motor 226, pure water, electrolyte or sample is introduced from the second switch valve 120 through the connection line 124. After the flow rate is precisely set, the second motor 226 is reversely rotated to raise the piston 222, and the pure water, the electrolyte, or the sample 104 introduced as the piston 222 is raised is moved to the first line ( It is supplied to the third switch valve 130 through L1).

The third switch valve 130 is introduced from the nitrogen gas cylinder 160 through the seventh line L7, including a first preset position for discharging the liquid introduced into the first line L1 to the second line L2. A third conduit 132 is provided at one of a second setting position and a third setting position for selectively supplying the nitrogen gas to the second line L2 and the fourth line L4 to open and close the flow path. have. Nitrogen gas is used to remove the material remaining in the fine conduit after the measurement. As such, the next measurement is performed after the material in the microtubule is completely removed, thereby enabling accurate quantitative analysis.

The fourth switch valve 140 receives the liquid (pure, electrolyte, sample) introduced through the second line (L2) through the third line (L3) according to the set position of the fourth conduit (142). The standard sample introduced from the third precision injector 230 through the sixth line L6 or through the third line L3 is supplied to the cell 12 through the third line L3. In addition, after the measurement is finished, the nitrogen gas flowing in from the nitrogen gas cylinder 160 via the third switch valve 130 or the fifth switch valve 150 and the material in the pipeline through the eighth line (L8). And discharge to (178).

The fifth switch valve 150 supplies the standard sample introduced from the standard sample container 180 to the fifth line L5 according to the set position of the fifth pipe 152, and the third precision injector 230 The standard sample introduced through the fifth line L5 is supplied to the cell 12 through the fourth switch valve 140.

In the third precision injector 230, a piston 232 operatively connected to the third motor 236 through the piston rod 234 is mounted to slide. Therefore, when the piston 232 is lowered by the operation of the third motor 236, the standard sample is introduced from the fifth switch valve 150 through the fifth line (L5). After the flow rate is precisely set, the second motor 226 is reversely rotated to raise the piston 232, and the standard sample introduced as the piston 232 rises is transferred to the fourth line through the sixth line L6. Supplied to the switch valve 140.

After completion of the measurement, the mercury and the solution in the cell 12 is discharged to the recovery container 178 through the ninth line (L9). The materials recovered to the recovery container 178 are discharged by the operation of the vacuum pump 176. In addition, as described above, the material of the pipe flows into the recovery container 178 through the eighth line L8 according to the introduction of nitrogen gas.

The following describes the process for measuring trace elements using a system with this configuration.

For the analysis of trace elements, the sample and the standard sample are injected into the cell one by one, the potential difference is measured, and their results are calculated by computer. To this end, first, the second conduit 122 of the second switch valve 120 is positioned as shown by the dashed-dotted line. Accordingly, the electrolyte contained in the electrolyte container 102 flows into the second precision injector 220 via the line 108 to be accurately metered, and then the third switch valve 130 and the fourth switch valve 140. Is supplied to the cell 12 via. In this case, the third conduit 132 and the fourth conduit 142 in the third switch valve 130 and the fourth switch valve 140 are positioned as shown by the dotted lines, respectively.

Next, the second conduit 122 of the second switch valve 120 is positioned as shown by the dotted line. Accordingly, the sample contained in the sample container 104 flows into the second precision injector 220 via the line 110 and is accurately metered, and then the third switch valve 130 and the fourth switch valve 140. Is supplied to the cell 12 via.

After dilution by supplying the electrolyte and the sample at an appropriate ratio, nitrogen gas is supplied to remove dissolved oxygen in the cell 12. At this time, the third pipe 132 in the third switch valve 130 is positioned as shown by the dotted line, the nitrogen gas introduced from the nitrogen gas cylinder 160 through the seventh line (L7) is the second line (L2). ) Is supplied into the cell 12 via the fourth switch valve 140 and the third line L3. As described above, after removing the obstacles inside the cell 12, the agitator 22 is operated to stir, and then the drop is performed using the first switch valve 40 and the first precision injector 60 in the above-described order. A mercury working electrode is produced to measure the potential difference.

After the measurement of the sample is finished, the standard sample is supplied into the cell 12 using the fifth switch valve 150 and the third precision injector 230. That is, when the third motor 236 is operated in the state in which the fifth pipe 152 is positioned in the L-shape, the piston 232 is lowered and is contained in the standard sample container 180 through the fifth line L5. Standard sample is introduced. When the third motor 236 is reversely rotated after the quantity is introduced, the standard sample in the third precision injector 230 is supplied to the fourth switch valve 140 through the sixth line L6, and at this time, the fourth switch The fourth conduit 142 of the valve 140 is located in a L-shape and supplies the introduced standard sample into the cell 12 through the third line L3.

In this way, the standard sample is injected into the cell to measure the potential difference, and the computer calculates the measured value of the sample and the standard sample to complete the analysis.

After the measurement is completed, the internal solution in the cell 12 must be removed for the next measurement. At this time, in order to prevent contamination, after the mercury drop is removed, the mercury electrode is regenerated using the first precision injector 60, and the vacuum pump 176 is operated to draw the solution in the cell 12 into the ninth line ( Recovery to the recovery container 178 through L9).

If the standard is replaced or the system is initially commissioned, air may be present in the fine conduit. The air in the pipeline can be removed with pure water. That is, the pure water discharged through the line 106 is sucked into the second precision injector 220 in a state where the first pipe line 46 in the first switch valve 40 is positioned as shown by the solid line. Discharge to line 1 (L1).

In this case, the second conduit 122 of the second switch valve 120 is positioned as shown by the solid line, and the fifth conduit 152 of the fifth switch valve 150 is positioned as shown by the dotted line, The pure water introduced through the first line L1 passes through the fourth line L4 and the fifth line L5 in turn, and the fourth pipe 142 of the fourth switch valve 140 is disposed as shown in the solid line. After being discharged to the eighth line (L8) through the), and sent to the recovery container 178 can remove the existing standard sample in the conduit, and also to remove the air in the third precision injector 230 It is possible.

According to the present invention described above, since the first precision injector is used, the correct amount of mercury droplets can be deposited in the recess formed in the upper end of the capillary tube, and there is no need to replace the electrode with a new one even when inspecting the high concentration of contaminants. . In addition, mercury drops hold down the mercury column on the capillary wall, preventing mercury drops from being broken, and the equipment can be installed on-site and measured by accurate metering. There is an advantage.

Claims (1)

The mercury introduced from the mercury storage container 50 through the cell 12 having the reference electrode 16, the auxiliary electrode 18, and the capillary tube 30 on which mercury is seated is installed, and the supply pipe 54. Mercury sucked through the first switch valve 40 selectively supplied to 30) and the first pipe line 46 mounted on the first switch valve 40 by the operation of the first motor 66. In the dropwise mercury electrode comprising a first precision injector 60 to supply to the capillary 30, A second opening for selectively supplying the liquid container 100, the electrolyte container 102, and the sample container 104 to the connection line 124 by selectively opening the pure water container 100, the electrolyte container 102, and the sample container 104 according to the set position of the second pipe line 122. Switch valve 120, A second precision injector 220 for supplying the liquid introduced through the connection line 124 by the operation of the second motor 226 to the first line L1 connected to the second switch valve 120; Nitrogen gas introduced from the nitrogen gas cylinder 160 through the first set position and the seventh line L7 for supplying the liquid introduced into the first line L1 to the second line L2 is connected to the second line (L7). A third switch valve 130 having a third conduit 132 for opening and closing the flow path at any one of a second set position and a third set position selectively supplied to L2) and a fourth line L4; A fourth switch valve 140 for supplying the liquid introduced through the second line L2 to the cell 12 through the third line L3 according to the set position of the fourth pipe 142; A fifth switch valve 150 for supplying the standard sample introduced from the standard sample container 180 to the fifth line L5 according to the set position of the fifth pipe 152; The standard sample introduced through the fifth line L5 is sucked under the control of the third motor 236, and then supplied to the cell 12 via the sixth line L6 and the fourth switch valve 140. And the third precision injector 230, By the operation of the vacuum pump 176, the fluid discharged from the fourth switch valve 140 is introduced through the eighth line (L8) according to the set position of the fourth conduit 142, the inside of the cell 12 The trace element measuring system using a dropping mercury electrode, characterized in that it comprises a recovery container 178 which is introduced into the solution and mercury in the ninth line (L9).