Sample injection needle cleaning and drying device

Abstract

The application discloses a sample injection needle cleaning and drying device, characterized in that: comprising a heatable hot cleaning chamber and an airflow flow limiting valve; the hot cleaning chamber comprises a spacer, a cover, a cylindrical wall and a base; the top of the hot cleaning chamber is an inverted circular table structure, the spacer is fixed in the circular table at the top end of the cylindrical wall through the cover, and a through hole for inserting the sample injection needle is arranged at the center of the bottom surface of the circular table and the cover respectively; the upper part and the lower part of the cylindrical wall are respectively provided with an air inlet through hole and an air outlet through hole; the air inlet through hole and the air outlet through hole are connected with quick couplings through threads, the quick couplings are connected with an air path connecting pipe; the air outlet through hole at the lower part of the cylindrical wall is connected with the gas flow limiting valve capable of controlling the airflow of the air outlet; and the lower end of the cylindrical wall is movably and sealingly connected with the base. The cleaning sample injection needle residual sample device is used for cleaning the residual gas or liquid sample of the sample injection needle, can effectively improve the sample injection repeatability of the sample injection needle, is simple to use, and is good in reliability.

Description

Technical Field

[0001] This invention belongs to the field of pipeline cleaning and rinsing in chemical analysis, and specifically relates to a needle cleaning and drying device. Background Technology

[0002] The sample injector is an essential component in chemical analysis and detection instruments. In chemical experiments, the injection needle is used to aspirate samples. Since the needle comes into direct contact with the sample, inadequate cleaning can lead to cross-contamination. Therefore, the cleanliness of the injection needle is crucial. However, current technology lacks a cleaning design for needles used for aspirating samples. Sample residue adhering to the needle can affect the detection results, especially in the detection of trace substances, causing significant errors.

[0003] Ji Guoli invented a device for cleaning and drying the outer wall of a sample injection needle (patent number CN201721111437.8). The technical problem this invention solves is to provide a sample injection needle cleaner that effectively removes liquids and impurities adhering to the needle, avoiding cross-contamination caused by incomplete needle cleaning during testing. It facilitates needle cleaning, reduces cleaning time, saves resources, has a simple structure, and is easy to operate, thus overcoming the shortcomings of existing technologies. This invention is particularly effective at cleaning the outer wall of the sample injection needle, but its internal cleaning effect is less than ideal.

[0004] Hao Jun et al. invented a needle cleaner (patent number CN201621162103.9). This utility model discloses a needle cleaner, which includes a cleaner body with two parallel air outlet chambers and a water outlet chamber inside. The cleaner body has an air inlet ring, a water inlet ring, and a through hole penetrating the cleaner body, the air outlet chamber, and the water outlet chamber. The needle cleaner provided by this utility model can effectively remove liquid and impurities adhering to the needle, avoid cross-contamination caused by incomplete cleaning of the needle during testing, and facilitate needle cleaning. However, the removal effect of this invention on heavily adsorbed acids needs improvement.

[0005] In summary, the sample testing process requires the extensive use of injection needles, which need to be cleaned and dried after use. Traditional cleaning methods, such as manual cleaning and natural air drying, are time-consuming, inefficient, and yield unsatisfactory results, significantly impacting the analytical results. Summary of the Invention

[0006] To address the problems of long cleaning and air-drying times, low efficiency, and poor results associated with traditional needle cleaning methods, this invention provides a needle cleaning and drying device.

[0007] The specific content includes:

[0008] A sample needle cleaning and drying device includes a heatable hot cleaning chamber and a gas flow limiting valve. The sample needle is used after sample collection but has not been cleaned or has not been used for a long time. The hot cleaning chamber includes a septum and a cover, a cylindrical wall, and a base. The top of the hot cleaning chamber is an inverted frustum structure. The septum is fixed inside the frustum at the top of the cylindrical wall by the cover. The bottom surface of the frustum and the cover are respectively provided with through holes for sample needle insertion. The upper and lower parts of the cylindrical wall have air inlet and air outlet holes, respectively, for clean air flow. The air inlet and air outlet holes are respectively connected to quick-connect couplings via threads, and the quick-connect couplings are connected to a gas connection pipe. The air outlet hole at the lower part of the cylindrical wall is connected to a gas flow limiting valve that controls the airflow at the outlet. The lower end of the cylindrical wall is connected to the base via a threaded seal.

[0009] Furthermore, in the above technical solution, the hot cleaning chamber is a sealed chamber with an inner liner tube for guiding the incoming airflow. The cylindrical wall has a double-layer structure, with an inner layer being a heat-conducting metal layer and an outer layer being an insulation material. The sandwich layer of the double-layer cylindrical wall is heatable. The hot cleaning chamber contains a total of 3 through holes, with the upper through hole connected to a septum. The two through holes on the side of the chamber are the inlet and outlet for the cleaning gas flow direction.

[0010] Furthermore, in the above technical solution, the top of the hot cleaning chamber is an inverted frustum structure. The center of the bottom surface of the frustum has a circular through-hole with an inner diameter of 0.5-1 mm. A septum covers the circular through-hole on the bottom surface of the frustum, and the septum is fixed to the top of the cylindrical wall by a sleeve cap. The inner diameter of the through-hole on the upper surface of the sleeve cap is 0.5-1 mm. The circular through-hole at the center of the bottom surface of the frustum and the through-hole on the sleeve cap are on the same coaxial line, allowing the injection needle to directly penetrate into the hot cleaning chamber.

[0011] Furthermore, in the above technical solution, the hot cleaning chamber comprises a three-layer structure: an outer insulation layer, a middle sealing and heating layer, and an inner liner layer. The inner liner layer guides the incoming airflow while reducing contamination of the middle layer structure. An air inlet hole at the upper end of the circular tube wall connects to a clean air source.

[0012] Furthermore, in the above technical solution, the heating temperature range of the hot cleaning chamber is 25-200℃, and heating helps to thermally desorb residual samples from the injection needle and dry them.

[0013] Furthermore, in the above technical solution, the lower end of the cylindrical wall is connected to the base by threads. The upper surface of the base has a groove structure, in which adsorption material for the large amount of residual sample that has not been blown out in the adsorption chamber is embedded; the adsorption material is glass fiber filter paper, glass microfiber filter paper, or adsorption membrane material.

[0014] Furthermore, in the above technical solution, the gas outlet hole on the upper part of the cylindrical wall is connected to a flow limiting valve to control the gas flow from the outlet. The gas flow rate in the thermal desorption chamber can be adjusted according to the actual sample to avoid a rapid drop in the chamber temperature.

[0015] Furthermore, in the above technical solution, the inflow airflow in the hot cleaning chamber is set and controlled at 200-1000 sccm, and the outflow airflow in the hot cleaning chamber is set and controlled at 200-1000 sccm. Under normal circumstances, it is more beneficial to improve the cleaning effect if the inflow airflow in the hot cleaning chamber is greater than the outflow airflow.

[0016] This invention provides a method for cleaning and drying injection needles. Using the above-mentioned device, if the injection needle has not been cleaned after taking a sample or has not been used for a long time, firstly, the injection needle is repeatedly cleaned with cleaning solvent 3-5 times; then, the injection needle with a full-scale dose of cleaning solvent is inserted into the constant temperature heating device of this invention; and then the injection needle is blown by airflow for 30 seconds to 3 minutes.

[0017] The cleaning solvent is consistent with the target sample solvent; including: water, ethanol, isopropanol, methanol or n-hexane.

[0018] When placing the syringe cleaning and drying device, the base should be on a horizontal plane and the cylindrical wall should be placed vertically, which helps to improve the cleaning effect based on gravity.

[0019] This invention patent provides a needle cleaning and drying device. Through the structural design of various functional modules in the cleaning chamber, it can clean the needle by applying three physical principles: liquid gravity, gas flow field, and thermal desorption efficiency. It is a device that can quickly clean the needle, thoroughly clean both the inner and outer walls at the same time, and also dry the needle, thus significantly improving the cleaning effect and efficiency.

[0020] Advantages of the invention

[0021] 1. The present invention provides a needle cleaning and drying device that improves cleaning efficiency through the combined effects of gravity, airflow purging, and thermal desorption.

[0022] 2. The sample needle cleaning and drying device of the present invention is designed for cleaning samples that are prone to remain on both the inner and outer walls of the sample needle. The purge gas resides in the hot cleaning chamber, resulting in higher thermal desorption efficiency of the residual sample. Attached Figure Description

[0023] Figure 1 Schematic diagram of a needle cleaning and drying device Figure 1 ;

[0024] 1. Injection needle, 2. Septum, 3. Inner liner, 4. Cylinder wall, 5. Gas outlet, 6. Gas flow control valve, 7. Gas inlet, 8. Gas outlet, 9. Base, 10. Adsorbent material, 11. Cap.

[0025] Figure 2 An ion mobility spectrometry (IMP) tracing spectrum of acetone residue was obtained after cleaning the injection needle using a needle cleaning and drying device.

[0026] Figure 3 Ion mobility spectra were obtained after cleaning the injection needle with lactic acid residue using isopropanol solvent. Detailed Implementation

[0027] Example 1

[0028] A needle cleaning and drying device includes a heatable hot cleaning chamber and a gas flow limiting valve. The hot cleaning chamber includes a septum 2 and a cover 11, a cylindrical wall 4, and a base 9. The top of the hot cleaning chamber is an inverted frustum structure, i.e., a downward recessed groove. The septum 2 is fixed inside the frustum at the top of the cylindrical wall 4 by the cover 11, i.e., inside the groove, with the cover covering the upper part of the groove. The center of the bottom surface of the frustum and the cover 11 are respectively provided with through holes for inserting a needle 1. The upper and lower parts of the cylindrical wall 4 are respectively provided with an air inlet 7 and an air outlet 5. The air inlet and air outlet are respectively connected to quick connectors by threads, and the quick connectors are connected to a gas connection pipe. The air outlet 5 at the lower part of the cylindrical wall 4 is connected to a gas flow limiting valve 6 that can control the airflow at the outlet. The lower end of the cylindrical wall 4 is movably and sealingly connected to the base 9.

[0029] The hot cleaning chamber is equipped with an inner liner 3 that guides the incoming airflow. The cylindrical wall 4 has a double-layer structure, with an inner layer being a thermally conductive metal layer and an outer layer being an insulation material. The sandwich layer of the double-layer structure of the cylindrical wall 4 can be heated. A heating rod and a PT sensor are connected to the outer side of the inner layer of the cylindrical wall 4 to achieve heating and temperature control.

[0030] The top of the hot cleaning chamber is an inverted frustum structure. At the center of the bottom surface of the frustum is a circular through-hole with an inner diameter of 0.5-1 mm. A spacer 2 covers the circular through-hole on the bottom surface of the frustum. The spacer 2 is fixed to the top of the cylindrical wall 4 by a cover 11. The inner diameter of the through-hole on the upper surface of the cover 11 is 0.5-1 mm. The circular through-hole at the center of the bottom surface of the frustum and the through-hole on the cover 11 are on the same coaxial line.

[0031] The air inlet 7 at the upper end of the round tube wall is connected to a clean air source.

[0032] The heating temperature range of the hot cleaning chamber is 25-200℃.

[0033] The lower end of the cylindrical wall 4 is connected to the base 9 by threads. A residue collection area is formed between the interior of the lower end of the cylindrical wall 4 and the upper part of the base 9.

[0034] The upper surface of the base 9 has a groove structure, in which an adsorption material 10 is embedded to hold a large amount of residual sample that has not been swept away in the adsorption chamber; the adsorption material 10 is glass fiber filter paper, glass microfiber filter paper or adsorption membrane material.

[0035] The inflow airflow in the hot cleaning chamber is set and controlled at 200-1000 sccm, and the outflow airflow in the hot cleaning chamber is also set and controlled at 200-1000 sccm. The inflow airflow in the hot cleaning chamber is not less than the outflow airflow.

[0036] When placing the injection needle cleaning and drying device, the base 9 should be placed on a horizontal plane, and the cylindrical wall 4 should be placed longitudinally.

[0037] A method for cleaning and drying a syringe injection needle involves using the aforementioned syringe injection needle cleaning and drying device. A 1μL micro-syringe injection needle 1 is taken, and 1μL of acetone headspace vapor (1ml of acetone saturated vapor at 25℃) is accurately measured and discharged. The injection needle 1 is then repeatedly cleaned three times with methanol. Next, the injection needle 1 containing 1μL of methanol is inserted through the through-hole on the upper surface of the cleaning device, and the needle rod is repeatedly pushed five times. The temperature of the hot cleaning chamber is set to 150℃. The inflow airflow to the hot cleaning chamber is set to 300 sccm, and the outflow airflow is set to 200 sccm. Cleaning lasts for 2 minutes. The hot airflow within the chamber helps clean the inner and outer walls of the injection needle 1. Finally, air is drawn from the injection needle 1 and injected into an ion mobility spectrometer for detection (under normal conditions, the migration tube temperature is 100℃, the injector temperature is 150℃; the drift gas flow rate is 500 sccm, and the carrier gas flow rate is 300 sccm). No residual acetone signal was detected. Figure 2 As shown.

[0038] Example 2

[0039] Using the syringe cleaning and drying device described in Example 1, two 5μL microsyringes were used to collect 10ppm and 5μL of lactic acid samples in isopropanol, respectively, followed by sample discharge. Then, each syringe was cleaned three times with 5μL of isopropanol. Next, one syringe was filled with 5μL of isopropanol and inserted through the through-hole on the upper surface of the cleaning device to expel the isopropanol. The temperature of the hot cleaning chamber was set to 150℃. Circular glass fiber filter paper was placed on the base of the hot cleaning chamber to absorb any dripping liquid from the syringes. The inflow airflow to the hot cleaning chamber was set to 500 sccm, and the outflow airflow was set to 400 sccm. Cleaning lasted for 2 minutes. The last two injection needles were respectively introduced into an ion mobility spectrometer for detection (migration tube temperature 100℃, injector temperature 180℃; drift gas flow rate 500 sccm, carrier gas flow rate 300 sccm). Injection needles cleaned with isopropanol solvent according to the apparatus and method of this invention, and injection needles cleaned only with isopropanol repeatedly three times, were each injected with 2 μL of isopropanol solvent into the ion mobility spectrometer (ion migration tube 100℃, thermal desorption injector 150℃) for detection. Figure 3 As shown in Figures (b) and (a), it is evident that the device and method of this invention effectively remove lactic acid residue from the injection needle after cleaning with isopropanol solvent. Further analysis using 2 μL of isopropanol solvent from a blank injection needle yields the following results: Figure 3(Figure c) (The detection conditions and methods are consistent), and the signal detected by the blank injection needle after cleaning is basically consistent with that of the needle.

Claims

1. A method for cleaning and drying a sample injection needle, characterized in that: If the injection needle has not been cleaned after sample collection or has not been used for a long time, first clean the injection needle repeatedly with cleaning solvent 3-5 times; then insert the injection needle with a full-scale filler of cleaning solvent into the injection needle cleaning and drying device; then blow the injection needle with airflow for 30s-3min; the cleaning solvent is consistent with the target sample solvent. The needle cleaning and drying device includes: a heatable hot cleaning chamber and a gas flow limiting valve; the hot cleaning chamber includes a septum and a cover, a cylindrical wall and a base; the top of the hot cleaning chamber is an inverted frustum structure, the septum is fixed inside the frustum at the top of the cylindrical wall by the cover, and the center of the bottom surface of the frustum and the cover are respectively provided with through holes for needle insertion; the upper and lower parts of the cylindrical wall are respectively provided with an air inlet and an air outlet; the air inlet and air outlet are respectively connected to quick connectors by threads, and the quick connectors are connected to a gas connection pipe; the air outlet at the lower part of the cylindrical wall is connected to a gas flow limiting valve that can control the airflow at the outlet; the lower end of the cylindrical wall is movably and sealingly connected to the base; The hot cleaning chamber is equipped with an inner liner tube that guides the incoming airflow. The cylindrical wall has a double-layer structure, with an inner metal layer that conducts heat and an outer insulation material. The sandwich layer of the double-layer cylindrical wall can be heated. The upper surface of the base has a groove structure, which is embedded with adsorbent material that adsorbs a large amount of residual sample that was not blown out in the hot cleaning chamber; the adsorbent material is an adsorption membrane material.

2. The method for cleaning and drying a sample injection needle according to claim 1, characterized in that: The bottom surface of the frustum has a circular through hole with an inner diameter of 0.5-1mm at its center. A spacer covers the circular through hole on the bottom surface of the frustum. The spacer is fixed to the top of the cylindrical wall by a sleeve cover. The inner diameter of the through hole on the upper surface of the sleeve cover is 0.5-1mm. The circular through hole at the center of the bottom surface of the frustum and the through hole on the sleeve cover are on the same coaxial straight line.

3. The method for cleaning and drying a sample injection needle according to claim 1, characterized in that: The air inlet hole on the upper part of the cylindrical wall is connected to a clean air source.

4. The method for cleaning and drying a sample injection needle according to claim 1, characterized in that: The heating temperature range of the hot cleaning chamber is 25-200℃.

5. The method for cleaning and drying a sample injection needle according to claim 1, characterized in that: The lower end of the cylindrical wall is connected to the base by threads.

6. The method for cleaning and drying a sample injection needle according to claim 1, characterized in that: The inflow airflow in the hot cleaning chamber is set and controlled at 200-1000 sccm, and the outflow airflow in the hot cleaning chamber is also set and controlled at 200-1000 sccm. The inflow airflow in the hot cleaning chamber is not lower than the outflow airflow.

7. The method for cleaning and drying a sample injection needle according to claim 1, characterized in that: When placing the injection needle cleaning and drying device, the base should be placed on a horizontal plane and the cylindrical wall should be placed vertically.

Images