JPS60231202A - High pressure mixing type gradient elution device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a high-pressure mixing type gradient elution device. More specifically, the present invention relates to a high-pressure mixing type gradient elution device that can eliminate problems caused by changing the solvent structure into steps and is particularly useful as a carrier supply device for chromatography.

(B) Prior Art Conventionally, when performing a high-pressure gradient using multiple liquid pumps and a controller that supplies flow rate setting signals to them, it is not possible to simply apply a voltage corresponding to the set flow rate.
For example, the setting of at least one solvent in the mixed solvent is 0 to 1.
When there is a step change such as 00%, troubles such as the pump drive motor not being able to follow such a sudden change and stopping may occur. This tendency is especially strong when a pulse motor is used.

Therefore, in many cases, as shown in Figure 4, a filter (19) consisting of a large capacity capacitor and a resistor is installed between the voltage control circuit and the pump to slow the rise in rotation of the pump drive motor. It is being done.

However, when such a filter is installed, even if it is possible to prevent the motor from stopping, the total flow rate of the solvent may change temporarily due to an error in the filter's time constant due to variations in capacitor capacity. Unfavorable for chromatography. Furthermore, when a capacitor with a large capacity is used, its leakage current causes an error in the voltage setting for the pump, so there is a limit to the adjustment that can be made using such a filter.

(c) Purpose This invention was made in view of the above circumstances, and is a high-pressure mixing system that allows each pump to operate normally while keeping the total flow rate constant even when the composition ratio of the gradient solvent changes significantly in a stepwise manner. The purpose of the present invention is to provide a type of gradient elution device.

(D) Structure (According to the present invention, there is a high-pressure mixing type gradient elution device that is equipped with a plurality of pumps, a plurality of solvent channels supplied from the pumps, and a mixing channel that collects these solvent channels. , there is a comparison section that compares the flow rate control value that controls the drive section of each pump with the intended flow rate setting value every minute unit time, and a comparison section that compares the flow rate control value that controls the drive section of each pump with the intended flow rate setting value, and a comparison section that compares the flow rate control value that controls the drive section of each pump with the intended flow rate setting value. The pump is characterized by comprising a control unit that applies a minute change that approaches the flow rate setting value at each minute unit time and adjusts so that the sum of the minute changes in each pump for each minute unit time becomes zero. A high pressure mixing type gradient elution device is provided.

The present invention will be described in detail below with reference to the accompanying drawings.

(E) Example As shown in FIG. 1, numeral 11 indicates an embodiment of the high-pressure mixing type gradient elution apparatus of the present invention, and numeral 2 indicates a high-performance liquid chromatograph unit connected thereto.

The gradient elution device (1) is for a three-component gradient equipped with two plunger pumps (A), (B), and (C), and each solvent storage tank contains water (3) and methanol. (4) and acetonitrile (5) are stored.

Of course, these may be repeated twice or more times. These are connected to each solvent flow path (31) at a predetermined flow rate ratio.
, (41), (51) to the mixing block (6
), and then a high performance liquid chromatograph section (2) having a sample injection port (11), a column (7), a detector (8), and a data processing device (9).
The liquid is sent to.

The pumps (A), (B), and (C) are basically controlled by a flow rate setting value input section (14), a comparison section (12), a flow rate control section (13), and a pump drive section (10). Based on the flow rate control value from the flow rate control unit (13), the drive voltage (10a) of the pulse motor of each pump (10
b) (10c) is set at pump drive α.
The flow rate control value of each pump is then compared with the intended flow rate setting value in the comparison section (12), and if they do not match, the current flow rate control value is adjusted to approach the setting value in the flow rate control section (13). With this corrected new flow rate control value, the drive voltage (10a) (1
0b) (10c) is corrected. The feed bank of flow rate control values is performed every minute unit time (usually 10 to 100 III seconds) managed by a clock pulse, and the overall control thereof is performed by a microprocessor. A more detailed circuit configuration of the comparison section (12), flow rate control section (13), and pump drive section (10) is shown in FIG. In the figure, (15) is a microprocessor (#i8085A), (1B) is an interval timer (#8253-5), (17) is a ROM that stores comparison and control programs, and (18) is a flow rate control value and settings. RAM to write and read values as appropriate, (
20) is a driver corresponding to the pump drive unit (10). A driver (20) is attached to each pump, and these specifications are specified by A and A on the address bus.
This is done using the -A1 bit, and the data of the flow rate control value is transferred on the data bus using the -D3 bit.

On the other hand, the correction of the flow rate control value is performed by giving the flow rate control value a minute change that can approach the set value based on a pattern of magnitudes decoded from the comparing section.
Such a minute change is determined by how many dipkle values are changed, with the resolution of the dipkle value representing the flow rate applied to the D/A converter of the driver (20) being one unit, and usually the minute change per unit time as described above. , the change in pump flow rate is set to be ±lθ to 100 μl.

The sum of the minute change values for each pump is adjusted to zero. This adjustment is performed at the same time as setting minute changes based on the above-mentioned size pattern.

The flowchart of the program that performs such control is shown in the third section.
Shown in the figure. The parallel plus/minus and zero signs in the diagram indicate the magnitude relationship between the set values corresponding to pumps (A), (B), and (C) and the current control value. Value=control value O1 set value <control value minus - represents the pattern. Then, corresponding to each pattern, the change value given to each control value is adjusted and set in the direction of approaching the set value. The minimum unit of the change value at this time is α, the sum of the change values corresponding to each pump is zero, and the program is set so that the sum of the absolute values of each change value is 4α.

As a result, the control value is gradually corrected, the control value is output to the pump drive section, and the period ends.
By repeating this routine every minute unit time as described above, the intended flow rate of each solvent is set.

According to such a high-pressure mixing type gradient elution device, even when performing a step-like gradient operation that rapidly changes the set value, a continuous but gentle voltage change is caused to the pump drive motor. Therefore, the drive motor can follow the rotation sufficiently, and the troubles of conventional motors do not occur. Moreover, since the sum of the minute change values is controlled to zero, the total flow rate is always kept constant even when the flow rate of each solvent changes rapidly.

Note that the minimum unit of the change value can be determined in accordance with the appropriate flow rate change value per minute unit time mentioned above. In addition, in this invention, it is not necessary to use the previously employed filter for mitigating voltage changes as described above, but a filter with a small time constant is installed between the pump drive unit and the pump in order to remove noise mixed in from the outside. This is a more preferred embodiment.

(f) Effects As mentioned above, the high-pressure mixing type gradient elution device of the present invention allows the total flow rate to be maintained without changing even when the composition ratio setting changes significantly in a stepwise manner. Since voltage changes are not relaxed by a filter like in the past, errors in voltage setting due to capacitor leakage current can be virtually prevented.Therefore, it is possible to accurately perform the intended gradient operation. It is useful as a solvent supply device for various chromatography applications.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing an example of a high-performance liquid chromatography device using the high-pressure mixing type gradient elution device of the present invention, FIG. 2 is a configuration explanatory diagram showing the main control circuit of the elution device, and FIG. The same figure is a flowchart illustrating a program for controlling the flow rate, and FIG. 4 is a configuration explanatory diagram showing the main parts of a conventional high-pressure mixing type gradient elution device. (1)--High pressure mixing type gradient elution device, +21
- High performance liquid chromatography section, (3) - Water, (41-methanol, (5) - Acetonitrile, (6) - Mixing block, (7)
- Column, (8) - Detector, (9) - Data processing device, Qlm - Pump drive unit, (11") - Sample injection port, (12) - Comparison unit, (13) -・-Flow rate control section, (14) +--Flow rate setting value input section, (15)-Microprocessor, (16)-Interval timer, (17)--ROM, (1B)-RAM. (19)- -・-filter, (20)-driver, (31), (41), (51)-m-solvent channel,
(61) - Mixing channel, (A) (B) (C) - Plunger pump.

Claims (1)

[Claims] 1. In a high-pressure mixing type gradient elution device equipped with a plurality of pumps, a plurality of solvent channels supplied from the pumps, and a mixing channel that collects these solvent channels, each pump A comparison section that compares the flow rate control value that controls the drive section and the intended flow rate set value every minute unit time, and a comparison section that compares the flow rate control value that controls the drive section with the intended flow rate set value, and a comparison section that compares the flow rate control value that controls the drive section with the intended flow rate set value, and a comparison section that compares the flow rate control value that controls the drive section with the intended flow rate set value. A high-pressure mixing gradient, characterized in that it is provided with a control unit that applies such a minute change in each minute unit time and adjusts the sum of the minute changes in each pump for each minute unit time to be zero. Elution device.