JPH06258310A - Metal-component analytical apparatus - Google Patents

Abstract

PURPOSE:To provide a metal-component analytical apparatus wherein it excludes an influence caused by an irregularity and a noise in the analyzed value of an analysis means due to the pulsation of a pump used to supply a reducing agent. CONSTITUTION:The title apparatus is constituted in such a way that an eluent supply means 101 used to supply an eluent containing a reducing agent used to reduce metal ions is installed on the upstream side of concentration columns 8, 9. Thereby, a reducing-agent supply means which is installed in the upstream position immediately in front of an analysis means 32 in conventional cases is omitted, and it is possible to prevent a pulsation by the pressurization pump of the reducing-agent supply means from being transmitted to the analysis means 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal component analyzer which eliminates the influence of noise caused by variations in the analysis value of the analysis means due to pulsation of a pump used for supplying a reducing agent.

[0002]

2. Description of the Related Art FIG. 5 shows such a metal component analyzer.
The configuration shown in is provided. In FIG. 5, six sample liquid inflow passages 1A to 1F into which the sample liquid is fed are connected to the sampling valve indicated by reference numeral 1, and one of the sample liquid inflow passages 1A to 1F is connected to the sample liquid supply passage 30 (30).
selectively connected to a). The sample liquid that has flowed into the sample liquid supply passage 30 a is supplied to the sample liquid supply passage 30 by the liquid feed pump 2.
It is sent to the reactor 3 through b. A reaction solution supply passage 37 including a reaction solution storage tank 15 in which a reaction solution is stored and a hydrochloric acid pump 16 is connected to the upstream side of the reactor 3, and a reaction for ionizing a metal in a sample solution is performed. The liquid is added to the sample liquid. Then, the sample solution to which this reaction solution is added is mixed in the reactor 3 and then heated to a predetermined temperature, and as a result, the metal in the sample solution is dissolved and ionized. In this reaction liquid storage tank 15, as a reaction liquid, a colloidal dissolution liquid (HCl solution, concentration is 1.1 to
2.2 mol / l) is stored.

The sample liquid passing through the reactor 3 reaches the three-way flow path switching valve 5. The three-way flow path switching valve 5 allows a part of the sample solution flowing through the sample solution supply path 30 to flow through the flow path 13 to the drainage path 3
It leads to 4. That is, when the sampling valve 1 is switched and another sample liquid is supplied,
First, by switching the flow path to the flow path 13 side, the sample liquid supply path 30a between the sampling valve 1 and the three-way flow path switching valve 5 is provided.
Thoroughly wash off the previous sample solution remaining in ~ 30c.
Then, after that, the flow path is switched to flow the sample liquid toward (the pressurizing pump 6 side of) the sample liquid supply passage 30d. In addition, the sample liquid inflow passages 1A to 1F by the sampling valve 1
And the switching of the three-way flow path switching valve 5 are performed based on the signal output from the control unit C.

The sample liquid passing through the three-way flow path switching valve 5 is pressurized by the pressurizing pump 6. When the sample liquid is pressurized to a predetermined pressure or higher by the pressure pump 6, the pressure sensor 6A outputs a detection signal for stopping the operation of the pressure pump 6 to the control unit C. It is like this. The sample liquid pressurized by the pressure pump 6 passes through the first four-way channel switching valve 7 through the first concentration column 8 or the second concentration column 9, and the channels 8a and 8b and the channel 9a.
・ Supplied to 9b respectively.

The first four-way flow path switching valve 7 and the second four-way flow path switching valve 10 allow the sample solution supplied from the sample solution supply path 30 to pass through the concentration column 8 or 9 and then to the flow path 35. Flow path of the metal ion concentration step leading to the drainage path 34 through the eluent, and the eluent in the eluent storage tank 18 supplied from the eluent supply path 31 is passed through the concentration column 9 or 8 and then the flow of the analysis means 32. The metal ion elution step flow path leading to the path 33 is alternately formed for the concentration columns 8 and 9. That is, in the metal ion concentration step, when the sample solution passes through the concentration column 8 or 9, the metal ions in the sample solution are adsorbed by the concentration column 8 or 9, and in the metal ion elution step, the concentration column 8
Alternatively, the metal ion adsorbed on 9 is the eluent supply path 3
1 is eluted from the concentration columns 8 and 9 by the eluent supplied from 1 and conveyed to the analysis means 32, and adsorption of metal ions in the sample liquid to such concentration columns 8 and 9 (metal ion concentration step) , And elution (metal ion elution step) are alternately performed in each of the concentration columns 8 and 9.

[0006] Sample liquids of different types are alternately supplied to such concentration columns 8 and 9, and adsorption (concentration) and elution (concentration) of metal ions in the sample liquid to these concentration columns 8 and 9 ( The four-way channel switching valves 7 and 10 for alternately performing (analysis) are performed by switching the channel 35 measured by the flowmeter 19.
When the flow rate value of the sample liquid passing through the set value reaches a set value, or when a timer measures a preset time, it is performed by a signal transmitted from the control unit C.

When the eluent is pressurized by the pressure pump 17 to a predetermined pressure or higher, the pressure sensor 17A
The control unit C outputs a detection signal for stopping the operation of the pressurizing pump 17. Also,
The metal ions carried to the analyzing means 32 are separated into the separation column 11
The color is developed by the color-developing liquid from the post-color-developing-liquid supply passage 38, which has been purified in step 4, and the concentration is measured by the absorbance meter 12. The color-developing liquid is supplied from the color-developing liquid storage tank 21 to the color-developing liquid supply passage 38 by a color-developing liquid pump indicated by reference numeral 20. Further, a reducing agent supply means 100 is provided in the flow path 33 located between the four-way flow path switching valve 10 and the separation column 11. The reducing agent supply means 100 includes a reducing agent storage tank 60 that stores a reducing agent (ascorbic acid solution) that reduces iron, which is one metal component, from a trivalent state to a divalent state, and the reducing agent storage tank 60. From a reducing agent supply path 60a connecting to the flow path 33, and a liquid feed pump 59 for adding the reducing agent in the reducing agent storage tank 60 to the eluent in the flow path 33 via the reducing agent supply path 60a. It is composed.

In the figure, reference numeral 50 indicates
The pH of the sample solution is provided in the middle of the sample solution supply path 30c.
For adjusting pH to the optimum pH (that is, to increase the concentration efficiency) according to the characteristics of the concentration columns 8 and 9.
It is a regulator. The pH adjuster 50 has a structure in which an ion-exchange membrane is provided inside a hollow container, and the ion-exchange membrane forms two spaces inside the container. Then, the sample solution to which the reaction solution (acidic solution) is added is supplied to one side of these two space portions, and the alkaline pH adjustment liquid is used as the pH adjustment liquid for pH adjustment in the other space portion. A liquid, for example, a 0.1 to 1 normal tetramethylammonium hydroxide solution is supplied, and chlorine ions (from those contained in the hydrochloric acid of the reaction liquid) from the sample liquid into the pH adjusting liquid through the ion exchange membrane. ), And hydroxide ions move from the pH adjusting solution into the sample solution. That is, ion exchange is performed between the two, and the pH of the sample solution is adjusted. In this pH adjuster 50, for example, the pH of the sample liquid is adjusted to about 1.6 to 1.7 according to the characteristics of the concentration columns 8 and 9.

The pH adjusting liquid is supplied to and discharged from the pH adjuster 50 through the pH adjusting liquid supply passage 55 and the pH adjusting liquid outflow passage 56, respectively. That is, the pH
A pH adjusting liquid pump 58 is provided in the adjusting liquid supply passage 55.
The pH adjusting liquid stored in the H adjusting liquid storage tank 57 is sucked up, and the pH adjusting liquid after the ion exchange is discharged to the drainage passage 34 via the pH adjusting liquid outflow passage 56. Has become.

Further, a pH sensor 61 is provided in the middle of the sample liquid supply passage 30 (30c) located on the downstream side of the pH adjuster 50. Based on a detection signal from the pH sensor 61, a control unit is provided. C controls the feed amount of the pH adjusting liquid by the pH adjusting liquid pump 58.
Sample liquid supply path 3 between the pH adjuster 50 and the reactor 3
A part of 0c is formed in a coil shape, and the coil portion 30c 'formed in the coil shape is provided with a cooling fan 49 for cooling the sample liquid. The coil portion 30c 'is used as a cooling pipe for cooling the temperature of the sample liquid, and the sample liquid supply passage 30a at the rear is used.
It is formed to have a smaller diameter than that of, and is also used as a flow path resistor for increasing the pressure of the sample liquid in the reactor 3. A cooling fan 62 for cooling the entire reactor 3 so as not to overheat the reactor 3 is also provided near the reactor 3.

A check valve 63 is provided in the middle of the flow passage 30e leading to the drainage passage 34 of the three-way flow passage switching valve 5. The check valve 63 is opened by the discharge pressure of the sample liquid discharged from the pH adjuster 50, whereby the sample liquid supply path 3 is caused by the siphon phenomenon.
It is prevented that all the sample liquid in 0c flows into the drainage channel 34 leading to the drain. Further, in this figure, reference character C is a control unit for controlling the entire carbon content measuring device, reference character A is a personal computer for operating the control unit, reference character B is a graphic display showing the operating state of the carbon content measuring device, and reference character D is. The floppy disk device stores the control contents of the control unit C and the like.

The eluent stored in the eluent storage tank 18 of the reducing agent supply means 100 is 2,6 as the main component.
-Pyridinedicarboxylic acid is prepared by adding acetic acid and sodium acetate to pH 4.8 and having a buffering action. Further, in this eluent, 2,6-pyridinedicarboxylic acid was 6 m · mol / l and acetic acid was 50 m · mol / l.
1 and sodium acetate are contained at a concentration of 50 m · mol / l. The reducing agent solution stored in the reducing agent storage tank 60 of the reducing agent supply means 100 contains ascorbic acid at a concentration of 11 m · mol / l.

[0013]

By the way, in the metal component analyzer configured as described above, the reducing agent is added to the eluent after extracting the metal ions by the dedicated liquid feed pump 59. Therefore, due to the pulsation of the liquid feed pump 59, the liquid feed amount of the reducing agent by the liquid feed pump 59 is not constant, which causes a problem that the reduction rate of iron ions varies. Further, since the liquid feed pump 59 for supplying the reducing agent is arranged at the upstream position immediately before the analysis means 32, noise generated by the pulsation of the liquid feed pump 59 is generated by the separation column 11 of the analysis means 32 and the absorptiometer. 12 was affected, which caused a problem that the metal ion could not be accurately quantified.

The present invention has been made in view of the above circumstances, and the metal component analysis eliminates the influence of noise that is caused by variations in the analysis value of the analysis means due to the pulsation of the pump used for supplying the reducing agent. The purpose is to provide a device.

[0015]

In order to achieve the above object, in the present invention, an acidic solution is added to a sample solution containing a metal component to ionize the metal component in the sample solution, and further the sample solution After adsorbing the metal ion in the concentration column to the concentration column, the metal ion in the concentration column is eluted with an eluent, and then the metal ion in the eluent is analyzed by an analysis means on the downstream side of the concentration column. In the metal component analyzer for analysis, an eluent supply means for supplying an eluent containing a reducing agent for reducing the metal ions is provided on the upstream side of the concentration column.

[0016]

According to the present invention, since the reducing agent for reducing the metal ions is contained in the eluent and the liquid feed pump for supplying the reducing agent is eliminated, the pulsation of the liquid feed pump is analyzed. Transmission is prevented, so that the influence of the pulsation of the liquid delivery pump is eliminated in the analysis means. Further, by preliminarily containing the reducing agent in the eluent, variations in the mixing due to the pulsation of the conventional reducing agent feed pump are eliminated, thereby making the reducing agent supply amount uniform.

[0017]

EXAMPLES An example of the present invention will be described with reference to the piping diagram of FIG. 1, the metal component analysis results of FIGS. 2 and 3, and the reactor 3 of FIG. Since the basic constitution of the metal component device of FIG. 1 is the same as that of the “conventional technique”, only the different points will be described together with the operation thereof. In the metal component analyzer shown in this figure, conventionally, the analyzing means 32 and the four-way automatic switching valve 1 are used.
The reducing agent supply means 100 provided between the reducing agent supply means 100 and the reducing agent supply means 100 is omitted, and the reducing agent supplied by the reducing agent supply means 100 is supplied together with the eluent from the eluent supply part 101. ing.

The eluent supply unit 101 is a concentration column 8
An eluent storage tank 6 that is connected to a four-way automatic switching valve 7 located upstream of 9 and stores an eluent
4, an eluent supply path 31 connecting the eluent storage tank 64 and the four-way automatic switching valve 7, and an eluent in the eluent storage tank 64 provided in the middle of the eluent supply tank 31 A pressure pump 17 that supplies the automatic switching valve 7, and a pressure sensor 17A that is provided in the middle of the eluent supply path 31 and that detects whether or not the eluent is being supplied by the pressure pump 17 at an appropriate pressure. It consists of An eluent containing a reducing agent is stored in the eluent storage tank 64 of the eluent supply unit 101. It should be noted that 2,6-pyridinedicarboxylic acid contained in this eluent was 6 m · m.
ol / l, acetic acid of 50 m · mol / l, sodium acetate of 50 m · mol / l (above, components of the eluent) and a reducing agent of ascorbic acid of 1.
It is contained at a concentration of 3 m · mol / l.

By the way, the reducing agent ascorbic acid is contained at a concentration of 1.3 m · mol / l, and this concentration is experimentally determined in advance depending on the characteristics of the concentration column 8.9 and the separation column 11. Has been decided. That is, when the concentration of the reducing agent contained in the eluent is too high, the reducing agent ascorbic acid and the metal ions in the sample solution form a complex, and the metal in the separation column 11 is separated. Ions cannot be retained and metal ions cannot be separated. For example, if the concentration of ascorbic acid is 11
Concentration column 8 with an eluent adjusted to m · mol / l
・ Elution of the metal ions adsorbed on 9 and separation column 1
In the case of separation with 1, the peaks of the respective components could not be separated as shown in the chromatogram of FIG. 2, whereas the concentration of ascorbic acid was about 1/10 of 1.3.
Concentration column 8 with an eluent adjusted to m · mol / l
・ Elution of the metal ions adsorbed on 9 and separation column 1
It was confirmed that the peaks of the respective components could be separated at a sufficient height when the separation was carried out in No. 1 as shown in the chromatogram of FIG.

From the above experimental results, it is suitable that the concentration of ascorbic acid in the eluent is about 1.3 m.mol / l, and the concentration of ascorbic acid in the eluent is about 10 times higher than that of the ascorbic acid. It was confirmed that the performance of separating ions was poor. Then, according to such a method, an experiment was conducted in which the metal ions adsorbed in the concentration columns 8 and 9 were eluted with a plurality of kinds of eluents having various concentrations of ascorbic acid and separated in the separation column 11, It was confirmed that an eluent having an ascorbic acid concentration of 1 to 2 m · mol / l can produce a remarkable peak as compared with eluents having other ascorbic acid concentrations.

As described above in detail, in the metal component analyzer of this embodiment, the eluent for supplying the eluent containing the reducing agent for reducing the metal ions is provided on the upstream side of the concentration columns 8 and 9. Since the supply means 101 is provided,
The reducing agent supply means 100 is omitted, and the reducing agent feed pump 5 is provided.
The pulsation 9 is prevented from being transmitted to the analyzing means 32, and as a result, the analyzing means 32 can accurately analyze the metal ions. Moreover, since the reducing agent for reducing the metal ions is contained in the eluent in advance, the variation in the mixing due to the pulsation of the conventional reducing agent feed pump 59 is eliminated, and as a result, the conventional metal component analyzer As described above, the supply amount of the reducing agent does not vary, and in this respect, the effect of enabling accurate metal ion analysis can be obtained.

Now, the structure of the reactor 3 for ionizing the metal component in the eluent in FIG. 1 will be described in detail with reference to FIG. In FIG. 4, reference numeral 70 denotes a PEEK thin tube (inner diameter 0.5) corresponding to the sample liquid supply passage 30b in FIG.
mm). The PEEK thin tube 70 is made of polyether ether ketone (PEEK), and its end portion is connected to a PEEK tube 72 having an inner diameter larger than that of the PEEK thin tube 70 via a joint 71. This PEE
The K tube 72 is spirally wound around a metal cylinder 73, and the end thereof is connected to the sample liquid supply path 3 via a joint 74.
0c and PEE with the same inner diameter as PEEK thin tube 70
It is connected to the K thin tube 75. In addition, PEEK thin tube 70
・ Joints 71 ・ 74 connecting 75 and PEEK pipe 72
Are made of the same PEEK as the PEEK pipe 72.

A heater 76 is arranged vertically in the center of the metal cylinder 73, and the heater 76 has an upper end fixed to a case 78 via a bracket 77. That is, the metal cylinder 73 is provided with the heater 76.
It is supported only from above in the case 78 via the bracket 77 at the upper end of the above, so that the heat of the heater 76 is not unnecessarily transmitted to the outside. Further, on the upper surface and the lower surface of the metal cylinder 73, heat insulating plates 79 and 80 for preventing the heat of the heater 76 transmitted to the metal cylinder 73 from being radiated upward or downward are provided with screws 81 (screw 81). Is fixed only on the lower surface side).

On the other hand, the PEE wound around the metal cylinder 73
Around the K tube 72, a glass cloth tape 82 for further fixing the PEEK tube is wound. A temperature sensor 83 for detecting the temperature of the metal cylinder 73 is provided above the metal cylinder 73.
Based on the detected value of 3, when the control unit C detects that the temperature of the metal cylinder 73 rises above the threshold value in advance, the heater 76 is turned off, and the temperature of the metal cylinder 73 is changed. When it is detected in advance that the temperature has exceeded the threshold value and has decreased, the heater 76 is turned on. That is, the control unit C
Is a metal cylinder 73 based on the detection value of the temperature sensor 83.
The heater 76 is controlled so that the temperature of is constant.

In the reactor 3 having the above structure, the sample solution to which the reaction solution is added is supplied through the PEEK thin tube 70 and the PEEK tube 72, and the sample solution is supplied to the PEEK tube 72. It is heated by the heat of the heater 76 transmitted through the metal cylinder 73. At this time, the sample liquid in the PEEK tube 72 is
And a small diameter P connected at the end of the PEEK tube 72.
The pressure becomes high due to the diameter difference from the EEK thin tube 75. That is, the sample liquid in the PEEK tube 72 is heated at a high pressure by the heat of the heater 76 and the diaphragm formed at the connecting portion between the PEEK tube 72 and the PEEK thin tube 75, and as a result, the sample solution is heated. The metal component in the liquid is efficiently decomposed by the reaction liquid added previously. Moreover, the pipes 70, 72, which are used in this reactor 3
Since 75 and the joints 71 and 74 are all formed of PEEK, which has excellent heat resistance and mechanical strength, the constituent components of the pipes and joints do not elute into the sample liquid, and the analysis result by the analysis means 32 is obtained. The effect of not adversely affecting

[0026]

As described in detail above, in the metal component analyzer of the present invention, the reducing agent for reducing the metal ions is contained in the eluent, and the liquid feed pump for supplying the reducing agent is eliminated. Therefore, the pulsation of the liquid feed pump is prevented from being transmitted to the analysis means, and as a result, the influence of the pulsation of the liquid feed pump is eliminated in the analysis means, and the metal ion can be accurately analyzed. In addition, by preliminarily containing the reducing agent in the eluent, the variation in the mixing due to the pulsation of the conventional reducing agent feed pump is eliminated, and the reducing agent supply amount becomes uniform. It enables accurate analysis.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a metal component analyzer according to the present invention.

FIG. 2 is a chromatogram showing metal component analysis results when an eluent containing a high concentration of a reducing agent was used.

FIG. 3 is a chromatogram showing metal component analysis results when an eluent containing an appropriate concentration of a reducing agent is used.

FIG. 4 is a front sectional view showing a specific configuration of a reactor 3.

FIG. 5 is a schematic configuration diagram of a conventional metal component analyzer.

[Explanation of symbols]

 3 Reactor 8 Concentration column 9 Concentration column 11 Separation column 32 Analytical means 101 Eluent supply means

Claims (1)

[Claims] 1. An eluent after adding an acidic solution to a sample solution containing a metal component to ionize the metal component in the sample solution and further adsorbing the metal ion in the sample solution to a concentration column. The metal ion in the concentrating column is eluted by means of which the metal ion in the eluent is then analyzed by the analyzing means on the downstream side of the concentrating column. The metal component analyzer, wherein an eluent supply means for supplying an eluent containing a reducing agent for reducing the metal ions is provided on the upstream side.