JPS5997054A - Gradient elution apparatus - Google Patents

Abstract

PURPOSE:To obtain a gradient elution apparatus in which a minute diametered column stable in a mixing ratio is used, by combining a single plunger reciprocal type high pressure pump set to a high speed and a liquid feed flowline provided with a damper and a check valve. CONSTITUTION:Single plunger reciprocal type high pressure pumps each set to a high speed are used in liquid feed pumps PA, PB for respectively feeding two kinds of solvents A, B and the liquid feeds to a minute diameter column 1 from both pumps PA, PB are performed through liquid feed flowlines 16, 16' provided with dampers 23, 23' and check valves 24, 24'. In this case, pump drive motor control circuits 2, 2' control the pumps PA, PB so that either one of said pumps PA, PB is stopped when the other pump is used in a suction process. By this constitution, a gradient elution apparatus in which a minute diameter column stable in a mixing ratio is used can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microbore column (MicroBolumn) used for analyzing a trace amount of sample in, for example, a liquid chromatograph.
This invention relates to a gradient elution device that uses a re column (that is, a column with an inner diameter of about 1 nm) to feed a plurality of solvents while changing the mixing ratio over time, and gradient-elutes a sample through a mixer.

The above-mentioned micro-diameter column consumes an extremely small amount of solvent (about 2 to 2 VO) compared to a normal column, and has high separation performance, but in order to perform gradient elution using this column, the internal volume of the column is Since the flow rate is small, there are problems with the discharge capacity of the plunger of the pump that sends the liquid and the influence of the pulsating flow that occurs in the flow path, and a high-performance gradient elution device with a stable mixing ratio has not yet been developed. This is the current situation.

This invention was made in order to provide a gradient elution device for a micro-bore column, in which a plurality of liquid sending pumps are of a single plunger reciprocating type with a low flow rate constant discharge of, for example, 100 to 1 μl/win, The time for the suction step is the ejection time, for example, 60 to 6000 seconds.
For, '500 (0,2sec) or 1/L0
．． A high-speed suction liquid sending pump set at 000 (0-6 sec) is used, and a damper that absorbs the pulsating flow on the front delivery liquid pump side of each liquid sending channel and continues sending liquid during pump suction is installed. A check valve is provided downstream that allows flow only in the liquid feeding direction, and when any one of the plurality of liquid feeding pumps enters the suction process, all other liquid feeding pumps are shut off during that process. A liquid delivery bone pump drive control circuit is provided to stop the liquid supply.This is related to the characteristic gradient elution device. The purpose of the present invention is to provide a convenient device that can perform gradient elution without changing the mixing ratio of solvents even during the suction of each liquid pump, using a micro-diameter column with a liquid feed volume of approximately IAO. .

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a two-pump high-pressure mixing type gradient elution device as an embodiment of the present invention. The micro-bore column (1) has an inner diameter of 1 feather, approximately 20 mm.
It is used at a low flow rate of ~100 μm1/=i=. The liquid feed pump (FA) (PB) for this is a single small plunger reciprocating pump with a stroke of 100 μV as shown in Fig. 2, and its discharge and suction are controlled by the pump drive control circuit (2) (2'). For example, a pulse motor (3) (3) is controlled, as well as this motor (3).
(31) is operated by deformable cams (4) (4 (not shown in Figure 1)), and is capable of constant speed discharge from a minimum of 1 μn/-in to the above-mentioned 100 μA/mn. In other words, the discharge time is 1 at 10 μsha and 4 stops.
0=, 40V2 blood is set as 150 sec, and the suction process is 0.6sθC1 at 10μV-
For 100 μl, the suction time/discharge time ratio is set to a high speed of IAoo to 1/'LOOO, such as 0.2 sec. Figure 2 shows the pump drive control circuit (2) (two operations and pumps (PA) (PB)).
) with the discharge pressure detector (6) will be explained.

In other words, the command voltage from the gradient programmer (7) shown by the dotted line is applied to the voltage by the V/F converter (8).
The motor (3 to 3') is rotated by the signal A, and the cam (4) is driven to reciprocate the plunger (9). The position of this plunger (9) is detected by the position detector acJ. Input to the position monitor hole.

That is, at the point when the Gransha (9) finishes the discharge process, the pressure detector (6) inputs its discharge pressure, for example, 300 m, to the pressure storage/comparison circuit (6), stores this, and at the same time outputs the discharge pressure to the motor speed control circuit. α [Yes] inputs the high-speed suction stop signal to the current converter (8) K and switches the motor (3) to rapid rotation. Next, determine the position of the plunger (9) when the suction process is completed. is also detected and enters the constant-speed discharge process, but at this time, the check valve α→ on the pump discharge side does not open immediately.This is because the pressure inside the pump is decreasing, and the above A signal is sent to the V/F converter (8) to rapidly advance the plunger (9) in the direction of the arrow (-) for a short distance until the pressure is raised to the discharge pressure and the valve αa is opened to enter constant speed discharge. The discharge pressure is compared with the pressure previously stored in the circuit (a) above, and the motor (3) (3') is rotated at high speed until they are equal.
) is an operation for correcting the compressibility within the pump by storing the pressure immediately before the constant-speed discharge process. Returning to Figure 1, the above pump (FA
) (FB) is the sum of the flow rates (FA) and (FB) of two solvents (A) and (B) in their respective reservoirs αOσ5'), which are sent to each channel H (16). (F
While keeping A + FB) constant, mix concentration ratio K =
The above-mentioned gradient programmer (7) automatically changes FB/(F'A+FB) temporally according to a predetermined program. Two flow paths α・
The liquids (A) and (B) that have reached the confluence point (17) of (161) are mixed in the mixing chamber (g) and sent to the micro-bore column (1) through the sample injection port (0). The separated components are gradient eluted, detected by a component detector (e), and discharged into a drainage container (b).

For example, the flow rate of Karahiro (FA + FB) is 50μl/
If the win is set and the mixing concentration ratio ←) is 20%, then the pump (
The liquid feeding flow rate (2) of FB) is 10 μl/min. Therefore, in this case, the pump (FB) draws at high speed every 10 min, while the pump (FA) also pumps at a rate of about 2.5 min.
Suction at high speed every n.

Figure 3 is a time chart showing the situation, and Figure ■ is a time chart of the discharge flow rate (2 people) waveform by the pump (PA), where high-speed suction is approximately 0.5 at a period of 2.5- during tA.
This shows that See (ta) is performed one by one.

Figure ■ is a time chart of the (Fω waveform) caused by the pump (PB), with a period of tB+10m1n, approximately 0.6sec
) indicates that high-speed suction is being performed. Because the cycle is long, the mixing chamber (g) is filled with sea sand (a) with a particle size of approximately 0.3 to 0.5 M in a stainless steel tube (18I ()), and the connecting metal fittings at both ends ( If this is fixed by 18J), even if a single pipe or a mixing chamber filled with spherical particles is used that has a higher mixing effect, it will not be completely smooth, and the mixed concentration ratio (弒 changes during each pump suction as shown in Figure ■.This change is caused by a very small amount of liquid flowing back to the pump side at the beginning of the suction process (ta) of the pump (FA).
B) When that much liquid is sent to the mixing chamber (to), the mixing concentration ratio = FB O FA + FB) is (+ΔK
) For example, it increases by several units. At this time, the flow rate (FA + FB) to the mixing chamber (7) is controlled by the damper installed in the next flow path aQ) and the check valve (to) during pump suction (1; a). Also (FA
Since the flow rate of ) is almost maintained, (FA+FB) only decreases slightly. This is due to the action of a damper (not shown) (23 cylinders crush a stainless steel pipe with an inner diameter of about 5 mm, for example,
A flat flow path of about 0.27 ffW is formed, and this has an inner diameter of 10
Total length 2 sealed inside the tube with an elastic rubber filler
The flat flow path expands due to the discharge pressure, and contracts when the pump suctions to continue pumping liquid. In addition, the check valve ■ (24 is a normal check valve that allows fluid to flow in only one direction, and the spring (24S)
The ball (24B) (2
4B/) is in pressure contact with the valve seat, the (AXB) liquid is completely blocked by this valve (24/). For example, at the beginning of the pump (FA) suction, the (B) liquid This prevents the water from flowing back into the flow path αQ. The dampers and check valves for these flow paths are one of the essential parts of this invention. Next, returning to Fig. 3, when the pump (FB) enters high-speed suction (t b), as described above, (A) liquid increases (B) liquid decreases, and the mixture concentration ratio (R) (−ΔK ).Here, this invention reduces the change (±ΔK) in the mixture concentration ratio (a).
In order to eliminate this problem, for example, when the (FA) pump starts high-speed suction, a pump drive control circuit is provided that detects this and stops the liquid feeding of the other (FB) pump. In other words, when the (FA) pump is in the suction process, (F
B) The pump is stopped and the same < (Pea) pump is in the suction process (PA) By stopping the pump, the damper (A) (23) is activated and the flow rate is slightly reduced, but the same amount of (Pea) The A) and (B) liquids will be sent to the mixing chamber, and the mixed concentration ratio (埒) will not change as shown in Figure 3G.This pump drive control circuit (2) (2'
) is 22 signal line (a) in Figure 2 ((
25') (25')) is installed to detect that the plunger (9) has entered the suction process, and this detection signal is sent to the other pump motor to stop using the motor command circuit installed in the gradient programmer (7). configured to emit a signal.

The above is a two-pump type gradient elution device as an embodiment of this invention, but the mixed solvent is not limited to the above two types, and in the case of three or four types, the number of liquid sending pumps and their flow paths is increased. However, the same effect can be obtained by changing the contents of the programmer. Further, the damper is not limited to the one described above, and may be of any type.

This invention is configured as described above, and it uses a micro-diameter column with extremely low solvent consumption to completely eliminate changes in the mixing ratio during gradient elution during suction of the liquid pump, resulting in stable gradient elution. The present invention provides a convenient device that allows for high separation performance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the gradient elution device according to the present invention, FIG. 2 is a diagram of the liquid feeding pump drive circuit of the device and a compressibility correction circuit using discharge pressure storage, and FIG.
Figure ■ is a time chart showing the waveform of the flow rate jt (1'A) of the pump (FA), and figure ■ is a time chart showing the waveform of the flow rate (1'A) of the pump (FB).
FB) waveform time chart, figure ■ shows the above flow rate (FA
Time chart showing changes in mixing concentration ratio (XFB) (when one pump is suctioning and the other pump is discharging),
Figure Q shows the above mixed concentration ratio (
This is a time chart. PA-'J'B... Liquid pump (single plunger reciprocating high-pressure pump) A-B... Solvent l... Micro-bore column 2/21
... Pump drive motor control circuit FA-FB ... Predetermined flow rate fence of the above pumps (FA) (PB) Nakakanji 3, 3' ... Pump drive motor 7 ... Gradient programmer 9 ... Plunger 10... Plunger position detector 11... Granger position monitor

Claims (1)

[Claims] In an apparatus in which the mixing ratio of multiple types of solvents is changed over time using multiple liquid pumps and the liquid is sent to a micro-diameter column to elute the sample, the pre-delivery liquid pump is used in the discharge process to the column. A single plunger reciprocating high-pressure pump is set at a speed determined by a predetermined flow rate, and its solvent suction process is set at a higher speed than the discharge speed, and a pulsating flow is applied to the liquid feeding bong side of each liquid feeding channel. A check valve that allows flow only in the liquid feeding direction is provided downstream of the damper, and a damper that absorbs liquid and continues feeding the liquid during the suction process of the pump. 1. A gradient elution device comprising a liquid pump drive control circuit that detects when one of the liquid pumps enters a suction process and stops all other liquid pumps during that process.