CN103447268A - Automatic sample feeder and needle bath thereof - Google Patents

Abstract

The present invention provides an automatic sample injector and its needle washing tank. The needle washing tank includes an inner needle cleaning tank with a needle insertion hole and a liquid discharge end, and an outer needle cleaning tank with a needle insertion hole. , and a communication groove connected between the inner needle cleaning groove and the outer needle cleaning groove, the outer needle cleaning groove also has a through hole, and the upper end of the through hole communicates with the outer needle cleaning groove, The lower end of the through hole communicates with the outside of the needle washing tank. The needle washing tank of the present invention not only shortens the cleaning time of the sampling needle, but also prolongs the life of the syringe by modifying the structure of the outer needle washing tank.

Description

A kind of autosampler and its needle washing tank

technical field

The invention relates to a device for cleaning samples of analytical instruments, in particular to an automatic sample injector and a needle washing tank thereof. the

Background technique

The needle washing groove is usually used in chemical analysis instruments such as autosamplers. Its function is to clean the residual sample on the sampling needle used to draw chemical samples after each injection, thereby reducing the residual sample caused by multiple sample residues. cross-contamination. the

As shown in Figure 1, the basic structure of the current common needle washing tank is shown in the figure, wherein the needle washing tank 1 includes an outer needle cleaning tank 101, an inner needle cleaning tank 102 and a connecting tank 103, wherein the outer needle cleaning tank 101 is used to clean the outer wall of the sampling needle, the inner needle cleaning tank 102 is used to clean the inner wall of the sampling needle, and the communication groove 103 is connected between the outer needle cleaning tank 101 and the inner needle cleaning tank 102, so that the two tanks are connected. the

As shown in Figure 2, the needle washing process of the needle washing tank 1 is: S1, firstly the sampling needle 104 is inserted into the inner needle cleaning tank 102 of the needle washing tank 1, the syringe makes the sampling needle 104 start to drain, and the liquid washes the sampling needle 104 The residual sample on the inner wall is discharged from the inner needle cleaning tank 102, thereby completing the cleaning of the inner wall of the sampling needle 104; S2, the sampling needle 104 is inserted into the outer needle cleaning tank 101 of the needle washing tank 1, and the syringe causes the sampling needle 104 to start draining, After the liquid is filled with the outer needle cleaning tank 101, it flows from the connecting tank 103 to the inner needle cleaning tank 102 and is discharged. When the liquid is filled with the outer needle cleaning tank 101, it soaks and rinses the outer wall of the sampling needle 104 to achieve the purpose of cleaning the outer wall of the sampling needle 104. the

When the chemical analysis instrument performs each analysis, the liquid sample is drawn into the flow path of the analysis instrument by the sampling needle 104, so the inner and outer walls of the sampling needle 104 will be stained with the sample. If the samples on the inner and outer walls of the sampling needle 104 are not cleaned in time, these residual samples will cause cross-contamination with the next sample, thereby affecting the next analysis result. Therefore, after each analysis is completed, generally a larger volume of liquid is used to flush the inner and outer walls of the sampling needle 104 . the

In the prior art, when cleaning the sampling needle, a special high-precision quantitative syringe is usually used to push the cleaning liquid into the sampling needle for cleaning, and this will cause two problems. One is that the inner diameter of the sampling needle is very thin, If the injection speed is fast, it will generate a lot of pressure and cause leakage, so the injection speed needs to be set very low, and the corresponding volume flowing out from the sampling needle is small, and the volume of the syringe It is limited, and the cleaning volume of the cleaning sampling needle also needs to be guaranteed, so the cleaning time of the needle will be very long. Assume that the flushing volume required for needle washing is 2ml of lotion, the volume of the syringe is 250ul, and the time for pumping the syringe back and forth is 20 seconds, then the time for washing the needle is 4*20 seconds=80 seconds, if the lotion needed for needle washing more, it will take longer time; secondly, due to the low push speed of the syringe, less liquid is pushed out each time, so it is necessary to push the syringe multiple times to complete the entire needle washing process, and the number of times a syringe is used is Effective, so this will greatly shorten the life of the syringe. the

Finally, it can be seen that the needle washing tank in the prior art can produce two problems: 1. The flushing time is too long, which affects the use efficiency; 2. The service life of the syringe is shortened. the

Contents of the invention

In order to solve the problems existing in the prior art, the present invention proposes a needle washing tank which can shorten the needle washing time and prolong the service life of the syringe. the

The invention proposes a needle washing tank for an automatic sampler, which includes an inner needle cleaning tank with a needle insertion hole and a liquid discharge end, an outer needle cleaning tank with a needle insertion hole, and an inner needle cleaning tank connected to the inner needle The communication groove between the cleaning tank and the outer needle cleaning tank, the outer needle cleaning tank also has a through hole, the upper end of the through hole communicates with the outer needle cleaning tank, and the lower end of the through hole It communicates with the outside of the needle washing tank. the

In the needle washing tank of the present invention, the through hole may also be located at the bottom of the outer needle washing tank and communicate with the outer needle washing tank in a straight line. the

In the needle washing tank of the present invention, the lower end of the through hole can also be provided with a pipeline and a joint connected to each other in sequence, the outer diameter of the pipeline is 1/16 inch, and the inner diameter is 1/16 inch. /32 inches, the joints described are 10-32 threaded seal joints. the

In the needle washing tank of the present invention, the drain hole of the inner needle washing tank can also communicate with the outside through the side wall of the needle washing tank, and the included angle with the needle insertion hole of the inner needle cleaning tank is 85° Spend. the

In the needle washing groove of the present invention, the needle insertion hole of the inner needle cleaning groove and the needle insertion hole of the outer needle cleaning groove can also be arranged in parallel, and the diameter of the inner needle cleaning groove is the same as that of the outer needle cleaning groove. 1.5 times the diameter of the groove. the

In the needle washing groove of the present invention, the communication groove can also be connected between the needle insertion hole of the outer needle cleaning groove and the needle insertion hole of the inner needle cleaning groove, And communicate with two pin holes. the

In the needle washing tank of the present invention, the needle washing tank can also be made of materials corroded by organic solutions. the

The present invention also provides an automatic sample injector, which includes a cleaning pump and the above-mentioned needle washing tank, and the cleaning pump is connected to the lower end of the through hole of the needle washing tank. the

The needle washing tank of the present invention not only shortens the cleaning time of the sampling needle, but also prolongs the life of the syringe by modifying the structure of the outer needle washing tank. the

Description of drawings

Fig. 1 is a schematic structural view of a needle washing tank 1 in the prior art. the

Fig. 2 is a schematic diagram of the needle washing process in the needle washing tank 1 in the prior art. the

Fig. 3 is a schematic structural view of the needle washing tank 2 in the present invention. the

Fig. 4 is a schematic diagram of the needle washing process of the needle washing tank 2 in the present invention. the

Detailed ways

A preferred embodiment of the present invention will be introduced below in conjunction with the accompanying drawings. the

Referring to Fig. 3, the needle washing tank 2 is composed of a needle washing tank body 201 and a needle washing tank cover 202, wherein the needle washing tank body 201 is composed of an inner needle cleaning tank 203, an outer needle cleaning tank 204 and a communication tank 205, wherein the inner needle cleaning tank The groove 203 is composed of a needle insertion hole 208 and a liquid discharge hole 207 , and the outer needle cleaning groove 204 is composed of a needle insertion hole 209 and a through hole 206 . The inner needle cleaning tank 203 is used to clean the residual samples on the inner wall of the sampling needle, and discharges the residual liquid after cleaning the inner and outer walls of the sampling needle, and the outer needle cleaning tank 204 is used to clean the residual samples on the outer wall of the sampling needle, wherein the needle insertion hole 208 and 209 are used to insert the sampling needle into the inner needle cleaning tank 203 and the outer needle cleaning tank 204 respectively, the liquid discharge hole 207 is used to discharge the waste liquid after cleaning, and the through hole 206 is used to send the external cleaning liquid into the outer needle Cleaning tank 204. The communication groove 205 is arranged between the needle insertion holes 208 and 209 for communicating the inner needle cleaning groove 203 and the outer needle cleaning groove 204 . the

The inner needle cleaning tank 203 and the outer needle cleaning tank 204 are two cylindrical tanks arranged in parallel inside the needle washing tank body 201, because the inner needle cleaning tank 203 is not only used to clean the inner wall of the sampling needle, but also to remove the two Therefore, it is necessary to ensure the unobstructed flow path, so the diameter of the inner needle cleaning tank 203 is larger than the diameter of the outer needle cleaning tank 204, and the diameter of the inner needle cleaning tank 203 is usually selected to be the diameter of the outer needle cleaning tank 204. More than 1.5 times the diameter of the pipe, so as to ensure a smooth flow path. The lengths of the inner needle cleaning groove 203 and the outer needle cleaning groove 204 are greater than the depth of the sampling needle inserted into the sample bottle, that is, greater than the height of the liquid hanging on the outer surface of the sampling needle. the

The size of the connecting groove 205 also has a certain range, because if the connecting groove is too large, the waste liquid overflowing from the outer needle cleaning groove 204 will not flow into the inner needle cleaning groove 203 immediately. If it is too small, due to the influence of the surface tension of the liquid, the liquid will gather in the communication groove 205 to form a water drop and will not flow down from the inner needle cleaning groove 203. For some liquids with high viscosity, the water drop will be very large, resulting in a drop from the needle washing groove cover 202. overflow. the

The drain hole 207 is used to discharge the waste liquid generated after cleaning the sampling needle, so the drain hole 207 forms a certain angle with the needle insertion hole 208, which facilitates the waste liquid to flow out. In this embodiment, the drain hole 207 passes through The side wall of the needle washing tank body 201 communicates with the outside, and the included angle between the liquid discharge hole 207 and the needle insertion hole 208 is 85 degrees, at this time, the waste liquid can be better discharged. the

As another example, the drain hole 207 can also communicate with the outside through the bottom of the needle washing tank 201, and the angle between the drain hole 207 and the needle insertion hole 208 can also be other angles, as long as the waste liquid can be discharged . the

The through hole 206 is used to connect to an external cleaning pump, so as to send in liquid for cleaning the outer wall of the sampling needle. The upper end of the through hole 206 is connected with the bottom input end 210 of the outer needle cleaning tank 204, and the lower end of the through hole 206 is connected with the needle washing tank. 2, and the through hole 206 is in direct communication with the outer needle cleaning groove 204. In this embodiment, the lower end of the through hole is sequentially provided with a pipeline and a joint connected to each other. The outer diameter of the pipeline is 1/16 inch, the inner diameter is 1/32 inch, and the joint is a 10-32 threaded sealing joint. The pipeline is connected to the lower end of the through hole 206, and the infusion end of the cleaning pump connected to the needle washing is connected to the threaded sealing joint to form a straight flow path, so that the liquid from the external cleaning pump can enter the outer needle cleaning tank more quickly 204 inside. the

As another example, according to actual application requirements, sometimes for more convenient design, the through hole 206 may not be arranged at the bottom of the needle washing tank body 201, so the through hole 206 may also be arranged on the side wall of the needle washing tank body 201, At this time, the input end 210 at the bottom of the outer needle cleaning tank 204 needs to be connected to the infusion end of the external cleaning pump through a non-linear flow path, which can also achieve the purpose of the present invention. the

In this embodiment, the needle washing tank 2 is made of PPS (polyphenylene sulfide) plastic, which has very good corrosion resistance and can be molded by injection molding, which is more suitable for mass production. the

As another example, the needle washing tank 2 can also be made of stainless steel, PEEK plastic (polyether ether ketone), PTFE plastic (polytetrafluoroethylene) and other materials resistant to corrosion by organic solvents. the

Referring to FIG. 4 , the process of cleaning the sampling needle in the needle washing tank 2 will be described step by step. the

S1, cleaning the inner wall of the sampling needle 211

The sampling needle 211 is inserted into the inner needle cleaning tank 203, and then the liquid injector pushes out the liquid to make the sampling needle start to drain, and the inner wall of the sampling needle 211 is cleaned. Wash needle well 2 outside. the

S2: cleaning the outer wall of the sampling needle 211

The sampling needle 211 is inserted into the outer needle cleaning tank 204, and a cleaning pump is externally connected to the through hole 206. The cleaning pump starts to transport liquid upward through the bottom input end of the outer needle cleaning tank 204, and flushes the outer wall of the sampling needle 211. As the liquid increases, The liquid rises to the communication groove 205 , and then the liquid enters the inner needle washing tank 203 through the communication groove 205 , and finally the waste liquid carrying residual samples is also discharged to the outside of the needle washing tank 2 through the drain hole 207 . the

It can be seen that when the needle washing tank of the present invention cleans the outer wall of the sampling needle 211, the syringe no longer needs to transport the liquid, but an external cleaning pump is used to transport the liquid, and the liquid output by the cleaning pump directly enters the outer needle cleaning tank through the through hole 206 204 cleans the outer wall of the sampling needle, because the cleaning pump directly transports the liquid through the through hole without being constrained by the inner diameter of the sampling needle, so the infusion speed is faster than that of the syringe, so the time for cleaning the outer wall will be greatly shortened, and the entire cleaning The time of the needle will be shortened, and the use of the syringe is reduced, and the service life of the syringe is prolonged. the

The present invention also proposes an autosampler with a needle washing tank, including the needle washing tank 2 described above, and a cleaning pump. As mentioned above, the cleaning pump is connected with the threaded sealing joint at the lower end of the through hole 6 for When cleaning the outer wall of the sampling needle, the cleaning solution is sent to the outer needle cleaning tank 204. In this embodiment, the cleaning pump is a micropump. the

The above are only specific embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the within the protection scope of the present invention. the

Claims (8)

1. A needle washing tank for an automatic sampler, comprising an inner needle washing tank with a needle insertion hole and a liquid discharge hole, an outer needle washing tank with a needle insertion hole, and an inner needle washing tank connected to the inner needle washing tank The communication groove between the groove and the outer needle cleaning groove, It is characterized in that, The outer needle washing tank also has a through hole, the upper end of the through hole communicates with the outer needle washing tank, and the lower end of the through hole communicates with the outside of the needle washing tank. 2. The needle washing tank according to claim 1, wherein the through hole is located at the bottom of the outer needle washing tank and communicates with the outer needle washing tank in a straight line. 3. The needle washing tank according to claim 1 or 2, characterized in that, the lower end of the through hole is sequentially provided with a pipeline and a joint connected to each other, and the outer diameter of the pipeline is 1/ 16 inches, 1/32 inch inside diameter, the fittings described are 10-32 threaded seal fittings. 4. The needle washing tank according to claim 3, characterized in that, the drain hole of the inner needle washing tank communicates with the outside through the side wall of the needle washing tank, and is connected to the socket of the inner needle washing tank. The included angle of the pinhole is 85 degrees. 5. The needle washing tank according to claim 4, characterized in that, the needle insertion hole of the inner needle cleaning tank is arranged parallel to the needle insertion hole of the outer needle cleaning tank, and the diameter of the inner needle cleaning tank It is 1.5 times the diameter of the outer needle cleaning tank. 6. The needle washing tank according to claim 5, characterized in that, the connecting groove is connected between the needle insertion hole of the outer needle cleaning tank and the needle insertion hole of the inner needle cleaning tank , and communicate with the two pin holes. 7. The needle washing tank according to claim 1 or 6, characterized in that, the needle washing tank is made of materials resistant to corrosion by organic solutions. 8. An automatic sample injector, characterized in that it comprises a cleaning pump, and the needle washing tank as claimed in claims 1 to 7, the cleaning pump is connected to the lower end of the through hole of the needle washing tank .

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