JPS61112965A - Ion chromatograph apparatus - Google Patents

Abstract

PURPOSE:To easily and accurately set change-over timing, by driving a flow passage change-over valve in correspondence to a displayed chromatogram through a valve driving circuit by the output of a central processing unit. CONSTITUTION:The solution to be measured in a gauge tube 37 is fed to a first eluate 1a to reach a separation column 5a and the eluate is guided to a first detector 6a where, for example, the conductivity thereof is detected and a chromatogram is displayed. A keyboard 16 is operated while said chromatogram is observed to set a divisional taking time. Definite calculation is performed on the basis of the dead volume of piping or the flow amount of a pump in CPU13 to calculate a divisional taking volume and, when said volume is equal to or less tan the volume of a gauge tube 47, a first flow passage change-over valve 7 is turned ON for a predetermined time by the output of CPU13 and, about the time when the gauge tube 47 is filled with the solution of the part corresponding to an ion seed, a second flow passage change-over valve 4 is turned ON by the output of CPU13 and the solution is fed to a second eluated 1b to reach a second separation column 5b and further reaches a second detector 6b where, for example, the conductivity thereof is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an ion chromatograph apparatus for chromatographically analyzing ionic species in a liquid to be measured.

<Prior art> Using such an ion chromatography device, firstly, a first ion species (for example, a cation) in a liquid to be measured is analyzed,
A part of the liquid eluted from the first ion species analysis detector (hereinafter referred to as "first detector") is guided through the first flow path switching valve to the second flow path switching valve 11 and to the pipe, Thereafter, the second flow path switching valve is switched to pass the liquid in the measuring tube through a separation column, etc. to a second ion species analysis detector (hereinafter referred to as "second
A widely known method is to analyze a second ion species (for example, an anion) contained in the liquid to be measured by guiding the liquid to a detector (referred to as a detector). In this analysis method, the time is determined from the chromatogram drawn at what timing the first and second flow path switching valves are operated, and the fluid eluted from the first detector is switched to the second flow path switching valve at this time. The timing for switching the first and second flow path switching valves was determined by adding the time required for the valve to reach the metering pipe of the valve. Therefore, the operation for determining the timing is complicated, and the determined timing often does not match the actually required timing.

<Problems to be Solved by the Invention> The present invention has been made in view of this situation, and its purpose is to easily and accurately set the switching timing of the flow path switching valve that is actually required. An object of the present invention is to provide such an ion chromatography device.

<Means for Solving the Problems> A feature of the present invention is that by guiding a predetermined portion of the liquid eluted from the first ion species analysis channel to the second ion species analysis channel, both anion and cation ions in the liquid to be measured are removed. In an ion chromatography device that chromatographically analyzes species, an A/D
A converter, a display section, and a valve drive circuit are provided, and the flow path switching valve is driven via the valve drive circuit by the output of the central processing unit in correspondence with the chromatogram displayed on the display section. It is in.

<Conventional Example> The present invention will be described in detail below with reference to the drawings. The figure is an explanatory diagram of the configuration of an embodiment of the present invention, and in the figure, 1a is a tank in which eluent for cation analysis (hereinafter referred to as "first eluent") is stored, and 1b is a tank for storing eluent for anion analysis, for example. A tank in which a liquid (hereinafter referred to as "second eluent") is stored, 1
c is a tank in which a removal solution made of, for example, a dodecylbenzenesulfonic acid solution is stored; ld; le is a waste liquid tank;
2c is a liquid feeding pump, 3 is the first to sixth connection ports 31 to 36
and an injector having a metering tube 37 and whose internal flow path is alternately switched between a solid line connection state and a broken line connection state,
4 is a second flow path switching valve having first to sixth connection ports 41 to 46 and a metering pipe 47, and whose internal flow path is alternately switched between a solid line connection state and a broken line connection state; 5a and 5b are respectively, for example; first and second separation columns for cation analysis and anion analysis; 6a and 6b are first and second detectors, for example conductivity meters; 7 is the first to sixth connection lowers 1 to 6; 76 is a first flow path switching valve whose internal flow path is alternately switched between a solid line connection state and a broken line connection state; 8 is a first flow path switching valve;
- A third flow path switching valve having sixth connection ports 81 to 86 and whose internal flow path is alternately switched between a solid line connection state and a broken line connection state; A suppressor with a double tube structure divided into an inner chamber 92 and an outer chamber 93, 10 are separation columns 5a and 5b.
12 is an A/D converter for A/D converting the output of the detector circuit 11; 13 is an A/D converter for A/D converting the output of the detector circuit 11;
A central processing unit (hereinafter referred to as "CPU J"), which receives the output of the /D converter 12 and performs various arithmetic processing, is a 14-digit CPU.
In response to the output of 13, the first to third flow path switching valves 7.4.8
Valve drive circuit that turns on and off, 15 is CPTJ 1
For example, draw a chromatogram based on the output of step 3.
16 is a keyboard for inputting various setting values to the CPU 13; Same, Sable, Su9
is not necessarily necessary, and may be removed if the so-called background of the second eluent is low. Furthermore, a plotter may be used as the display section 15 instead of the CRT.

In the embodiment of the present invention having such a configuration, the first to third flow path switching valves 7.4.8 and the injector 3 are initially turned off, and all of these internal flow paths are A solid line is connected.

In addition, the liquid sending pumps 2a to 2c are
The flow rate of each of these pumps 2a to 2.degree. can be changed arbitrarily by operating a keyboard 16. When the pump 2a is driven, the first eluent in the tank 1a is transferred from the pump 2a to the first and second injectors 3.
Connection port 31.32→first and second of third flow path switching valve 8
Connection port 81.82→first separation column 5a,→first detector 6a→first and second connection lower 1. of first flow path switching valve 7.
72→Flows through the flow path of the waste liquid tank 1d. When the pump 2b is driven, the second eluent in the tank 1b is transferred from the pump 2b to the fifth and sixth connection ports 85 and 86 of the third flow path switching valve 8 to the second flow path switching valve 4. 1 and 2nd connection port 41.42 → 3rd and 4th connection port 83.84 of 3rd flow path switching valve 8 → 2nd separation column 5b → inner chamber 92 of suppressor 9 → 2nd detector 6b → waste liquid tank It flows in a flow path of 1d. When the pump 2c is driven, the removed liquid in the tank 1c flows through the channel from the pump 2c to the outer chamber 93 of the suppressor 9 to the waste liquid tank 1e,
Predetermined ions (for example, cations) in the liquids are exchanged between the liquid in the inner chamber 92 and the liquid in the outer chamber 93 via the liquid in the inner chamber 92 and the liquid in the outer chamber 93.

In this state, the liquid to be measured is injected into the measuring tube 37 from the fifth connection port 35 of the injector 3 using, for example, the syringe 38 . Thereafter, the injector 3 is turned on and its internal flow path is switched from the solid line connection state to the broken line connection state in the figure. At the same time, an on signal from the injector 3 is sent to the CPU 13, and the CPU 13 starts counting time. On the other hand, the temporary measurement liquid in the measuring tube 37 is carried by the first eluent and reaches the separation column 5a, and the first ion species (
For example, cations) are separated and second ionic species (for example, anions) are eluted earlier than the first ionic species.

The bathing liquid from the separation column 6a is guided to a first detector 6a, and its conductivity, for example, is detected. The output of the detector 6a is sent to a detector circuit 11 where signal processing such as amplification is performed, and then A/D converted by an A/D converter 12 and sent to a CPU 13. Based on the output of the CpU 13, a chromatogram based on the signal detected by the first detector 6a is displayed on the display section 15. Also, move the cursor etc. from all over this chromatogram and click the keyboard 16.
The preparative separation time is set by operating . In CPU 13,
Certain calculations are performed based on the dead volume of the piping, the flow rate of the pump, etc., and the fractional volume is calculated. When the fractional volume is within the capacity of the measuring tube 47, the output of the CpU 13 is used to calculate the fractional volume of the pulp drive circuit 14. 7) The internal flow path is switched from the solid line connection state in the figure to the broken line connection state. Therefore, the eluate of the portion corresponding to the first ion species (flows in the flow path from the chroma tube 47 shown in the display section 15 to the sixth and fifth connection ports 46.45). When the solution fills the measuring tube 47 (this time is also calculated in the CPU 13), the second flow path switching valve 4 is turned on via the valve drive circuit 14 by the output of the CPU 13, and the internal flow path is turned on. is switched from the solid line connection state in the figure to the broken line connection state.Therefore, the solution in the metering tube 47 is transported to the second eluent, and the second ion species is separated into the second separation column 5b. The ion species separated in this way are transported again by the second eluent, pass through the inner chamber 92 of the suppressor 9, and reach the second detector 6b. The output is output from the detector circuit 1 as in the case of the output from the first detector 6a.
1 and the A/D converter 12 to the CPU 13 to provide a chromatogram on the display section 15 and to switch the flow path switching valve via the pulp drive circuit 14. Note that the setting of the separation time is not limited to the above-mentioned setting method and can be modified in various ways, for example, it may be set as follows. That is, a method may be used in which a chromatogram is taken once under normal conditions, and then the preparative separation time is set without displaying the chromatogram on the display unit 15, and the switch operation on the keyboard 16 is performed simultaneously while taking the chromatogram. A method of setting the υ preparative time may also be used. Furthermore, in order to prevent the preparative collection time from exceeding the capacity of the measuring tube 47, the possible preparative range may be displayed on the display section 15 at the stage when the preparative start command is issued. Furthermore.

The present invention is not limited to ion chromatograph devices, but can be similarly applied to other liquid chromatographs.

<Effects of the Invention> According to the embodiment of the present invention as described in detail above, the CPt is
Since the configuration is such that the flow path switching valve is automatically driven by the output of 11-3 via the valve drive circuit 14, the switching timing of the flow path switching valve that is actually required can be easily and accurately set. It becomes like this.

[Brief explanation of drawings]

The figure is a configuration explanatory diagram of an embodiment of the present invention. 1a to 1e...tank, 2a to 2c...liquid pump, 3
...Injector, 4,7.8...Flow path switching valve, 5
a, 5b... Separation column, 6a, 6b... Detector, 9... Suppressor, 11... Detector circuit, 12.
... A/D converter, 13... Central processing unit, 14...
- Valve drive circuit, 15...display section, 16...keyboard.

Claims (3)

[Claims] (1) In an ion chromatograph device that chromatographically analyzes both negative and positive ion species in a liquid to be measured by guiding a predetermined portion of a liquid eluted from a first ion species analysis channel to a second ion species analysis channel, A/D converts the signal based on the output of the detector and sends it to the central processing unit
A converter, a valve drive circuit that switches a flow path switching valve according to a command from the central processing unit, and a display unit that receives an output from the central processing unit and displays a chromatogram, and a chromatogram displayed on the display unit. The ion chromatograph apparatus drives the flow path switching valve via the valve drive circuit with the output of the central processing unit in accordance with the output of the central processing unit. (2) The ion chromatography apparatus according to claim 1, wherein the first ion species is a cation and the second ion species is an anion. (3) The display section is a cathode ray tube.
) or (2).