JPH0560736A - Washing method of needle of autosampler for hplc - Google Patents

Abstract

PURPOSE:To obtain a washing method of a needle enabling execution of accurate measurement and suppressing occurrence of contamination, by washing surely the outside surface of the needle. CONSTITUTION:A washing liquid 30 is made to pass through the inside flow passage of a needle 37 according to an ordinary process, whereby washing of the inside is conducted. By switching a four-way valve 34 properly, subsequently, the washing liquid 30 in a prescribed quantity is once sucked into a metering syringe 35 and then the washing liquid accumulated in the metering syringe is jetted toward the outside surface of the needle through a washing liquid discharge pipe 38 and an injection nozzle 39a by pushing 35a a piston. This jetted washing liquid sticks on the outside surface of the needle and flows downward and thereby washing of the outside surface is completed. The washing liquid reaching the lowermost end of the needle is let to fall downward naturally and discharged onto the washing liquid reservoir tank 41 side through a drain pipe 40, as occasion arises, under a negative pressure generated by a vacuum pump 42, not sticking to the needle again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for washing a needle of an autosampler for HPLC.

[0002]

2. Description of the Related Art FIG. 4 shows an example of the configuration of a conventional measuring device for an HPLC autosampler. The operation principle will be briefly described with reference to FIG. First, the six-way valve 1 having the six ports A to F is for switching between the sample introduction route and the sample derivation route, and one of the flow paths shown by the solid line and the broken line is selected. Be electrically conducted. The sample suction tube 2 is moved downward while the flow path indicated by the solid line is in conduction, and the needle 3 provided at the tip thereof is inserted into the sample solution 5 filled in the sample bottle 4.
Then, the piston of the measuring syringe 6 is pulled, and a predetermined amount of the sample liquid 5 is sucked from the needle 3.

Next, the flow path of the six-way valve 1 is switched to the state shown by the broken line. In this state, the piston of the measuring syringe 6 is pushed to inject a predetermined amount of the sample solution into the sample loop 7. I will let you.

After that, the flow path of the six-way valve 1 is switched again to the state shown by the original solid line. Then, the eluent 10 in the storage tank 9 delivers the sample solution 5 in the sample loop 7 to the column 11 by the pump 8. Then, the sample solution 5 is separated into each component in the column 11 and detected by the detector 12.

When one measurement is completed, the inside of each channel is cleaned in preparation for the next measurement. Here, first, the inside of the flow path through which the eluent 10 has passed when the sample solution 5 is extruded is washed with the eluent 10. However, the eluent 10
, The needle 3 and the sample liquid suction pipe 2 are not washed with the eluent 10. Therefore, conventionally, the flow path of the three-way valve 13 is switched to the state shown by the broken line, and in this state, the piston of the measuring syringe 6 is pulled to suck the cleaning liquid 14 into the measuring syringe 6, and then the three-way valve 13
Switch the flow path of to return to the state of the original solid line. Then, the cleaning liquid 14 in the measuring syringe 6 is pushed by pushing the piston.
Is supplied to the needle 3 side through the sample liquid suction pipe 2 and discharged from the needle 3 to the outside. That is, the cleaning liquid 14 is caused to flow in the direction opposite to the above-described suction of the sample liquid. As a result, the inside of the sample liquid injection tube 2 and the needle 3 are cleaned.

By the way, since the tip of the needle 3 is inserted into the sample solution 5 when the sample solution is sucked, the sample solution 5 is also attached to the outer surface of the needle 3. Therefore, it is necessary to wash the sample solution 5 as well. Therefore, conventionally, as shown in FIG. 1B, when cleaning the inner flow path of the needle 3, the tip of the needle 3 is inserted and disposed in the bottomed cleaning port 16, and in that state, the above-mentioned inner flow path of the needle 3 is Wash. Then, the cleaning liquid 14 discharged from the tip of the needle 3 accumulates in the cleaning port 16, so that the accumulated cleaning liquid 14 ′ comes into contact with the outer surface of the needle 3, whereby the outside thereof is also cleaned. When a predetermined amount or more of the cleaning liquid 14 'is stored in the cleaning port 16, it is discharged to the outside through the drain pipe 17 provided on the upper side surface of the cleaning port 16.

[0007]

However, the above-mentioned conventional cleaning method has the following problems. That is, as shown in FIG. 3C, the cleaning process is completed, the needle 3 is moved upward, and the cleaning liquid 1 in the cleaning port 16 is moved.
When it is positioned above the liquid surface of 4 ', the outer surface of the needle 3 was in contact with the cleaning liquid 14' until just before that,
It will stop at a predetermined upper position while a small amount of the cleaning liquid 14 'is attached to its outer surface.

Then, a part of the cleaning liquid 14 'adhering to the outer surface of the cleaning liquid 14' becomes a droplet and is positioned so as to cover the lower end suction port 3a of the needle 3. When the next measurement is performed in this state, the sample liquid 5 may be sucked at the same time when the sample liquid 5 is sucked, and the droplet-shaped cleaning liquid 14 ′ located at the lower end of the needle 3 may also be sucked in from the lower end suction port 3 a. It becomes impossible to inhale exactly a predetermined amount.

Further, the needle 3 is added to the sample solution 5 in the sample bottle 4.
Since the cleaning liquid 14 ′ attached to the outer surface of the needle 3 may be mixed into the sample liquid 5 and diluted, the sample liquid 5 may be diluted, and in such a case, accurate measurement cannot be performed.

Furthermore, since the used cleaning liquid 14 'partially remains in the cleaning port 16, the remaining cleaning liquid 1
There is also a problem that 4'causes contamination and the needle 3 is also contaminated by inserting the needle 3 into the contaminated cleaning liquid 14 '.

The present invention has been made in view of the above background, and an object of the present invention is to reliably wash the outer surface of the needle so that accurate measurement can be performed and contamination is prevented. An object of the present invention is to provide a method for washing a needle of an autosampler for HPLC which is suppressed.

[0012]

In order to achieve the above-mentioned object, in the method of cleaning the needle of the HPLC autosampler according to the present invention, the inside flow for discharging the cleaning liquid to the outside by passing through the inner flow path of the needle. A path cleaning step, an outer surface cleaning step of discharging a cleaning liquid toward the outer surface of the needle, moving the discharged cleaning liquid downward along the outer surface and dropping the same, and the needle by the both cleaning steps. The step of discharging the used cleaning liquid separated from the outside to the outside without reattaching it to the needle.

[0013]

The inner channel of the needle is cleaned by passing the cleaning solution through the channel, and the outer surface of the needle is directly sprayed with the cleaning solution on the outer surface of the needle. The outer surface is reliably cleaned. When cleaning the outer surface, it is not necessary to store the cleaning liquid used for cleaning the inner channel in the cleaning port as in the conventional case, and it is not necessary to bring the stored cleaning liquid into contact with the outer surface of the needle. It is possible to prevent re-attachment of the cleaning liquid with a certain amount to the needle.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the method for cleaning the needle of the HPLC autosampler according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an example of an apparatus suitable for implementing the first embodiment of the present invention. As shown in the figure, the basic configuration of the measurement system is substantially the same as the conventional configuration described above. That is, by appropriately switching the hexagonal valve 20, the sample solution 22 in the sample bottle 21 is once stored in the sample loop 23, and then the eluent 26 in the storage tank 25 is supplied to the sample loop 23 side by the pump 24. As a result, the once stored sample liquid 22 is supplied to the column 27 and then to the detector 28.

Here, in the present invention, the lower end suction port 33 of the cleaning liquid suction pipe 33 is stored in the storage tank 32 filled with the cleaning liquid 30.
a is inserted and arranged, and the other end of the cleaning liquid suction pipe 33 is connected to the first port a of the four-way valve 34. On the other hand, the second port b of the four-way valve 34 is connected to the measuring syringe 35, and as shown in the figure, the measuring syringe 35 is connected with the first and second ports a and b of the four-way valve 34. The cleaning liquid 30 is sucked into the measuring syringe 35 by pulling the piston 35a.

Further, the third port c of the four-way valve 34 is connected to the port F of the six-way valve 20 via the sample liquid suction pipe 36, and the suction of the sample liquid 22 and the sample liquid suction pipe are performed as in the conventional case. 36 and the inside flow path of the needle 37 attached to the tip of the sample liquid suction tube 36 which is the object of the present invention.

Further, the fourth port d of the four-way valve 34 is
It is connected via a cleaning liquid discharge pipe 38 to an injection nozzle 39a mounted on the upper side wall surface of the cleaning port 39. As a result, the inside of the cleaning port 39 is electrically connected.

Further, in this embodiment, a drain port 39b is provided at the bottom of the cleaning port 39, one end of the drain pipe 40 is connected to the drain port 39b, and the other end of the drain pipe 40 is communicated with the cleaning liquid reservoir tank 41. .. The cleaning liquid storage tank 41 is connected to the vacuum pump 42.

A needle cleaning method according to the first embodiment of the present invention will be described with reference to the apparatus having the above structure. now,
It is assumed that the normal measurement of the sample liquid 22 is completed. Then, the needle 37 is moved in a predetermined direction, and the tip of the needle 37 is inserted into the cleaning port 39 as shown in the drawing. Then, the four-way valve 34 is
After the port a and the second port b are communicated with each other, a predetermined amount of the cleaning liquid 30 is sucked into the measuring syringe 35 by pulling a predetermined amount of the piston 35a of the measuring syringe 35.

Then, the flow path of the four-way valve 34 is switched so that the second port b and the third port c are in communication with each other. In this state, by pushing the piston 35a of the measuring syringe 35, the cleaning liquid 30 sucked into the measuring syringe 35 is transferred to the sample liquid suction pipe 36, the port A of the six-way valve 20,
It is discharged between the F and through the needle 37 from the lower end of the needle 37 into the cleaning port 39. As a result, each inner channel is washed. Further, in this example, while the cleaning liquid 30 is being discharged from the needle 37, the vacuum pump 42 is operated to suck the cleaning liquid 30 so that the discharged cleaning liquid is not accumulated in the cleaning port 39, but it is always operated. No need.

When the cleaning of the inner flow path is completed in this way, the process moves to the step of cleaning the outer side of the needle 37. That is, the four-way valve 34 is switched again to bring the first and second ports a and b into communication with each other as shown by the solid line. By pulling the piston 35a of the measuring syringe 35 in this state, a predetermined amount of the cleaning liquid 30 is supplied to the measuring syringe 35.
Inhale.

Next, the four-way valve 34 is switched to bring the second port b and the fourth port d into communication with each other. Further, the vacuum motor 42 is operated to start suction in the cleaning port 39. If you push the piston 35a in this state,
The cleaning liquid 30 stored in the measuring syringe 35 flows through the cleaning liquid discharge pipe 38 and is ejected from the ejection nozzle 39 a toward the outer surface of the needle 37. Then, the sprayed cleaning liquid 30 adheres to the outer surface of the needle 37,
Runs down. This allows the needle 37
The outer surface of the is cleaned. Then, the cleaning liquid reaching the lowermost end of the needle 37 is naturally dropped downward and is discharged to the cleaning liquid reservoir tank 41 side via the drain pipe 40 at any time due to the negative pressure of the vacuum pump 42, so that the cleaning port 39 Used cleaning liquid 30
It doesn't collect. Used cleaning liquid is needle 3
Reattachment to the outer surface of 7 is prevented.

When the cleaning of the outer surface of the needle 37 is completed, the vacuum pump 42 is stopped and the needle 37 is lifted and separated from the cleaning port 39. As described above, in this example, since the used cleaning liquid is not stored in the cleaning port 39, the cleaning liquid does not adhere to the outer surface of the needle 37 when the needle 37 moves upward as in the conventional case.

In this embodiment, the inner surface of the needle 27 is cleaned and then the outer surface of the needle 37 is cleaned, but the order may be reversed. In addition, although the cleaning liquid was once sucked into the measuring syringe 35 each time during such two washings, a relatively large amount of cleaning liquid is sucked at one time depending on the capacity of the measuring syringe 35 and the like. The inside and outside of the needle 37 may be cleaned by dividing the discharging step into two. With this configuration, the step of inhaling the cleaning liquid into the measuring syringe is reduced to one.
The number of times can be omitted and the system can be simplified.

Further, the operation timing of the vacuum pump 42 does not have to be performed before jetting the cleaning liquid 30 to the needle as in the above-mentioned embodiment, all the cleaning steps for the needle 37 are completed, and the needle 37 is moved upward. It is sufficient that the cleaning liquid is drained from the cleaning port 39 by operating the cleaning liquid before the operation, but it is preferable that the used cleaning liquid is accumulated in the cleaning port 39 and the vacuum is generated before the used cleaning liquid on the lower end of the needle 27 comes into contact with the cleaning liquid. Pump 4
2 is to be activated.

FIG. 2 shows an example of an apparatus for carrying out the second embodiment of the present invention. This example is different from the above-described first example in that the system for cleaning the inner channel of the needle 37 and the system for cleaning the outer surface are composed of two independent systems. That is, the system 45 for cleaning the inner flow path of the needle 37 connects the storage tank 48 filled with the cleaning liquid 47 to the first port a of the first three-way valve 46 in the same manner as the conventional device, and connects the second tank It is configured by connecting the first measuring syringe 50 to the port b and connecting the sample liquid suction pipe 51 to the third port c. As a result, by appropriately switching the first three-way valve 46, the cleaning liquid 47 is once sucked into the first measuring syringe 50, pushed out toward the sample liquid suction pipe 51 side, and the needle is inserted through the six-way valve (not shown). It can be supplied to the inner channel of 37.

On the other hand, the system 52 for cleaning the outer surface of the needle 37 connects the first port a of the second three-way valve 53 to the storage tank 55 filled with the cleaning liquid 54 and the second port b to the second port a. The measuring syringe 56 is connected, and the cleaning liquid discharge pipe 57 is connected to the third port c. Thereby, the cleaning liquid 54 is temporarily sucked into the second measuring syringe 56 by appropriately switching the second three-way valve 53, and is pushed out to the cleaning liquid discharge pipe 57 side, and is attached to the tip of the cleaning liquid discharge pipe 57. The cleaning liquid 54 can be sprayed toward the outer surface of the needle 37 located in the cleaning port 59 via the spray nozzle 59a.

That is, according to this embodiment, since the system 45 for cleaning the inner flow path and the system 52 for cleaning the outer surface of the needle 37 are independent of each other, the inner flow path and the outer surface of the needle 37 are separated. Can be washed at the same time.
Specifically, when the measurement of the sample liquid is completed, the needle 3
7 is moved so that its lower end is inserted and arranged in the washing port 59. At this time, the first and second three-way valves 46 and 53 are brought into communication with each other between the first and second ports a and b as shown by the broken lines. In this state, the first and second measuring syringes 5
The cleaning liquids 47 and 54 are once sucked into the respective measuring syringes 50 and 56 by pulling the pistons 0 and 56 by a predetermined amount.

After that, the two three-way valves 46 and 53 are switched to establish communication between the second and third ports b and c as shown by the solid line, and the pistons of both metering syringes 50 and 56 are pushed to store them in the syringes. The cleaning liquids 47 and 54 are discharged to the inner flow path and the outer surface of the needle 37 through the respective paths. As a result, the inner and outer surfaces of the needle 37 are simultaneously cleaned. Further, at the time of this cleaning, the cleaning liquid 4 is applied to the needle 37.
A vacuum pump (not shown) is operated before 7 or 54 arrives or at a predetermined time after arrival to suck and remove the used cleaning liquid at any time to prevent the cleaning liquid from accumulating in the cleaning port 59. ..

Since the other constructions, functions and effects are the same as those of the first embodiment, detailed description thereof will be omitted. Further, in this embodiment, the inner flow path and the outer surface of the needle 37 are cleaned at the same time, but it goes without saying that any one of them may be cleaned first.

FIG. 3 shows an example of an apparatus for carrying out the third embodiment of the present invention. This example is a modification of the above-described first example, and only the characteristic points will be described.
In the embodiment, by operating the vacuum pump, the used cleaning liquid accumulated in the cleaning port 39 is forcibly discharged to the outside, but in this embodiment, the process is not performed and the system is simplified. There is.

In order to carry out the above cleaning method,
In this example, the cleaning port 60 is formed in a cylindrical shape that is opened vertically, and the inner diameter thereof is made larger than that used in the first embodiment. Specifically, for example, the needle 37
W between the outer surface of the and the inner surface of the cleaning port 60
Is about several millimeters (about 1 millimeter in the first embodiment).

As a result, the cleaning liquid flowing through the inner flow path of the needle 37 spontaneously drops downward from the lower end thereof, and the cleaning liquid attached to the outer surface also moves downward along the outer surface thereof. The used cleaning liquid does not drop down from the lowermost position and reattach to the needle 37. Further, since the inner diameter of the cleaning port 60 is made large, the cleaning liquid is washed with the cleaning port 6 by the action of surface tension or the like.
It bridges between the inner surface of 0 and the outer surface of the needle 27 and does not stay there. Note that the other configurations and operational effects are the same as those of the above-described first embodiment, and therefore description thereof will be omitted.

[0034]

As described above, in the needle cleaning method for the HPLC autosampler according to the present invention, the inner channel of the needle is cleaned by passing the cleaning solution through the channel, and The outer surface is performed by directly injecting the cleaning liquid onto the outer surface, so that the outer surface of the needle can be reliably washed,
Accurate measurement can be performed.

Since the cleaning liquid used for cleaning is discharged to the outside as it is without accumulating in the cleaning port as in the conventional case, reattachment of the used cleaning liquid to the needle can be suppressed, and the used cleaning liquid It is also possible to prevent the problem of needle contamination due to contamination of the cleaning liquid.

Further, since the used cleaning liquid is discharged in this manner, there is almost no cleaning liquid attached to the needle after the cleaning process, and the cleaning liquid is mixed in the sample liquid during the next measurement, There is no possibility of diluting the sample solution.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of an apparatus suitable for carrying out a first embodiment of a needle cleaning method for an HPLC autosampler according to the present invention.

FIG. 2 is a main part configuration diagram showing an example of an apparatus suitable for carrying out a second embodiment of a needle cleaning method for an HPLC autosampler according to the present invention.

FIG. 3 is a main part configuration diagram showing an example of an apparatus suitable for carrying out the third embodiment of the needle cleaning method for the HPLC autosampler according to the present invention.

FIG. 4 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 30, 47, 54 Cleaning solution 37 Needle

Claims (1)

[Claims] 1. An inner flow path washing step of discharging a cleaning liquid to the outside by passing through the inner flow path of a needle, and discharging the cleaning liquid toward the outer surface of the needle, and discharging the discharged cleaning liquid to the outer surface thereof. An auto-sampler for HPLC comprising an outer surface washing step of moving it downward along with dropping it, and a step of discharging the used washing solution separated from the needle by the both washing steps to the outside without reattaching to the needle. How to clean the needle.