JPH0127089Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a method for accurately and reproducibly injecting samples, from precious and minute amounts to large amounts of samples, using a microsyringe without any waste in high-performance liquid chromatography, etc. Regarding the sample injector that can be used.

In the case of previously proposed sample injectors, in order to switch the high-pressure flow path using a hexagonal valve, it is necessary to remove the needle of the microsyringe into which the sample has been injected.
The sample injected into the sample holding tube mixes with the solvent and remains attached to the tip of the needle, flowing back toward the front of the valve sliding surface. Therefore, a part of the injected sample flows backward in this way, so there is a major drawback in that the complete amount cannot be injected. Particularly in the case of small amounts, accuracy and reproducibility cannot be guaranteed because the proportion of the sample that has flown back is large. Furthermore, the loop-holding syringe using a six-way valve, which is conventionally used in chromatography, is structurally incapable of injecting microscopic amounts of approximately 1μ to 30μ, and furthermore, septum syringes are unable to inject under high pressure. Also, there is a drawback that the septum can clog the syringe and flow path.

On the other hand, there is a method in which the microsyringe is inserted for injection and switched to the high-pressure flow path without being removed, but this method involves inserting the sample into the microsyringe B from slightly in front of the sliding part A, as shown in Figure 3a. When the sliding part A slides and switches in order to inject the third
As shown in Figure b, a dead volume C is generated between the sliding part A and the tip of the needle of the microsyringe B, and there is a sample loss of, for example, about 0.5μ during syringe injection. This type of injector has a fatal flaw in that it is necessary to inject an extra amount of the sample, which is extremely small and valuable. Moreover, turbulent flow occurs between the depot volumes, and the accuracy and reproducibility is significantly lowered, especially when a small amount is injected, which is undesirable.

The present invention was developed in view of the above, and its characteristics are that the valve body and the sliding valve are brought into sliding contact, and the sliding valve is rotated to transfer the sample in the sample holding tube to the column conduit tube. In a sample injector designed to switch to a flow path for press injection, a needle sleeve is attached to the sliding valve, the through hole of which connects to the sample injection hole on the sliding surface, and on the opposite side of the sliding surface of the sliding valve, held in contact with and separated from the sliding valve;
When the microsyringe retreats, the tip of the needle matches the sliding surface of the sliding valve and stops.
A needle guide is provided with a stroke such that when the microsyringe is pushed in, the tip of the needle enters the sample holding tube connected to the valve body, and the microsyringe is moved back through the needle guide via an expansion spring. The sample injector is characterized in that the sample injector is

Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments.

FIG. 1 shows the raw material of the syringe according to the present invention, and FIG. 2 is a sectional view of the sample syringe according to the present invention.

1 is a valve body, which is connected to each of the five piping branch pipes. The valve body 1 includes a bearing 2.
is attached, and a sliding valve 4 having a sliding surface 4' inside the bearing 2 is connected to the bearing 12 and the disc spring 1.
3 and a lock nut 14, and are tightened and assembled with a constant load. The sliding surface 4' is in close contact with the inner surface of the valve body 1. Further, the sliding valve 4 is rotatable by a handle 10,
It can be rotated to the stopper pin 11 position. 6 is a needle sleeve, which is the sliding valve 4.
and is fixed to the sliding valve 4 with a flange 5. A needle guide 7 is attached to the flange 5 via an expansion spring 8, and the needle guide 7 is slidable within the flange 5 at a constant stroke. This stroke is such that when the microsyringe 16 described later is retracted, the tip surface of the needle 16' matches the sliding face 4' of the sliding valve 4 and stops, and when the microsyringe 16 is pushed in, the needle 16' stops. 16' is a stroke that enters the sample holding tube 19 connected to the valve body 1. 9 is a cap for attaching the needle guide 7 to the flange 5 under pressure expansion. A bush 3 having a surface that comes into sliding contact with the sliding face of the sliding valve 4 and the valve body 1 is fitted into the sliding face. The bush 3 has an injection hole 3a and a connection groove 3.
b, 3c. As a result, the needle 16' of the microsyringe 16 inserted from the needle guide 7 is
It passes through the hole in the flange 5, through the hole in the needle sleeve 6, and then into the injection hole 3a in the bush 3. At this time, the tip of the needle 16', which has a straight cross section, is on the same plane as the sliding surface 4'. At this point, when the microsyringe 16 is pushed further against the pressure expansion spring 8, the tip of the needle 16' enters the valve body 1 through the injection hole 3a of the bush 3, and opens the flow path to the sample holding tube 19. inserted into. Inject the sample at this point. The injected sample reaches the connecting groove 3c of the bush 3 from the sample holding tube 19, and further flows into the drain conduit 22 (see FIG. 1A).

After that, when the force pushing the microsyringe 16 is released, the syringe 16 returns to its original position, and the tip of the needle 16' again matches the sliding surface 4'. At this point, by rotating the handle 10, the syringe 16 returns to its original position. 1. By rotating the sliding valve 4 in the direction of the arrow in FIG. 1A, high pressure is applied to one side of the sample holding tube 19, which holds the sample through the connecting grooves 3b and 3c, by the pump described later. The sample is transferred by switching the flow path to the pump conduit and the other side to the column conduit to be described later (see FIG. 1B).

In addition, 15 in the figure is a pipe joint, 17 is a syringe support rod, and 18 is a bracket. Further, 20 is a pump conduction pipe, to which high pressure is applied by the pump. 21 is a column conduction pipe, 22 is a drain conduction pipe, 23 is a drain receiving trough, and 24 is a drain discharge pipe.

As mentioned above, in the sample injector of the present invention, when switching the flow path to force-feed the sample in the sample holding tube to the column conducting tube by rotating the sliding valve, the needle 1
The tip of 6' is always retracted to the sliding surface 4', and since it stops at this sliding surface 4', the injected sample does not flow backwards from the sliding surface 4' toward the syringe. , since the sample always stops at the sliding surface,
There is no loss of sample at all, and it has the great effect of always injecting an accurate amount. In addition, since there is no dead volume between the sliding surface 4' and the tip of the needle 16', it is possible to avoid unnecessary waste such as injecting an extra sample in anticipation of sample loss, which was the case in the past. It can exhibit a remarkable effect in the clinical examination of various samples, and there are many practical applications and benefits.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the principle of the syringe that implements the present invention, Figure 1A is an explanatory diagram of the state in which a sample is injected from the syringe into the sample holding tube, and Figure 1B is a diagram showing how the sliding valve is rotated. Explanatory diagram of the state in which the sample in the sample holding tube is pumped into the flow path to the column conduit by moving the sample, 2nd
The figure is a sectional view of the sample injector of the present invention, and FIG. 3 is a partially enlarged sectional view of a conventional sample injector. 1... Valve body, 2... Bearing, 3... Bush, 4... Sliding valve, 5... Flange, 6...
Needle sleeve, 7...needle guide, 8...expansion spring,
9...Cap, 10...Handle, 16...Microsyringe, 16'...Needle, 17...Syringe support rod, 19...Sample holding tube, 20...Pump conduit tube, 21...Column conduit tube, 22...Drain conduit pipe.

Claims (1)

[Scope of utility model registration request] In a sample injector that is designed to bring the valve body and the sliding valve into sliding contact and turn the sliding valve to switch the flow path to force-feed the sample in the sample holding tube to the column conduction tube, the sliding valve has a transparent A needle sleeve is attached whose hole is connected to the sample injection hole on the sliding surface, and is further held on the opposite side of the sliding surface of the sliding valve so as to be in contact with and away from the sliding valve, so that when the microsyringe is retracted, the needle sleeve is attached. A needle guide is provided with a stroke in which the tip end of the needle stops when it coincides with the sliding surface of the sliding valve, and when the microsyringe is pushed in, the tip of the needle enters the sample holding tube connected to the valve body, A sample injector further characterized in that the needle guide is biased through a pressure spring so that the microsyringe retreats.