Purging and trapping instrument and purging and trapping method

Abstract

The invention relates to the technical field of chromatographic detection instruments, in particular to a purge and trap instrument and a purge and trap method.The purge and trap instrument comprises a bottom plate, a shell, a feeding mechanical arm, a purge device, a lifting table and a sample feeding device; according to the invention, the following problems existing in the process of purging and trapping samples in the prior art can be solved: sample bottles with different diameters cannot be correspondingly limited, so that the sample bottles are lack of stability; the purging needle cannot be cleaned, so that the purging needle carries a residual sample, and the analysis purity of the subsequent sample after purging is influenced; according to the invention, sample bottles with different diameters can be clamped and limited in multiple directions, and the sample bottles can be further limited by applying acting forces in opposite directions to the sample bottles, so that the stability of the sample bottles is ensured; the purging needle is cleaned when purging and trapping of each sample are completed, samples left on the outer wall of the purging needle can be removed, and the analysis purity and data accuracy of subsequent samples are prevented from being affected.

Description

Technical Field

[0001] The present invention relates to the technical field of chromatographic detection instruments, and particularly relates to a purge and trap instrument and a purge and trap method. Background Art

[0002] The purge and trap method uses flowing nitrogen, helium or other inert gases to extract the analyte from the sample, allowing the gas to continuously pass through the sample and release the volatile components in the sample. Then, a trap instrument is used to adsorb the purged organic matter, and subsequently, it is thermally desorbed and the sample is sent into a gas chromatograph for analysis. Usually, the sample to be purged can be a solid or a liquid sample. High-purity helium is often used as the purge gas, and an appropriate adsorbent can be selected in the trap instrument according to the properties of the components to be analyzed to trap the sample.

[0003] In the prior art, a large number of purge and trap instruments and corresponding devices have also been disclosed. For more accurate comparison, for example, the Chinese patent with the publication number CN216870471U discloses a fully automatic purge and trap instrument, which includes a base. A 100-position matrix sample tray is arranged on the base. A three-axis robotic arm device is arranged on one side of the 100-position matrix sample tray. The three-axis robotic arm device is used to place the sample bottle in the 100-position matrix sample tray into the sample bottle chamber arranged on the base. The collection pipeline in the sample bottle chamber is connected to a gas path module, and the gas path module is respectively connected to a U-shaped purge bottle and an internal standard bottle arranged in the housing above the base.

[0004] When the above prior art is used, under the action of pressure, the liquid in the internal standard bottle is transferred to the spiking position through a six-way valve, and then the internal standard is added to the sample. Therefore, it has the function of automatically adding the internal standard substance, can use the internal standard substance to calibrate and eliminate interference, and improve the accuracy of the analysis result.

[0005] However, in the process of purging and trapping the sample using the above prior art, there are still the following deficiencies: 1. Since different samples need to use sample bottles with different diameters according to their different forms during the purge and trap process, and the sample bottle needs to be lifted upward during the purge and trap process of the sample, the above prior art cannot perform corresponding limiting on sample bottles with different diameters, resulting in a lack of stability of the sample bottle during the purge and trap process, and thus easily causing the sample bottle to fall and affecting the purge efficiency.

[0006] 2. Also, since during the purging process of the sample, the purge needle usually needs to be inserted into the sample bottle and an inert gas is introduced, and a small amount of sample will adhere to the surface of the purge needle after use, but the above prior art cannot clean the purge needle, resulting in the purge needle carrying the residual sample into the sample bottle, affecting the analysis purity of the subsequent purged sample, and thus affecting the data accuracy.

[0007] Therefore, based on the above-stated viewpoints, there is still room for improvement in the purge and capture methods of the prior art. Summary of the invention

[0008] In order to solve the above problems, the present invention provides a purge trapping instrument, including a base plate, a shell is arranged on the upper end of the base plate, a feeding robot arm for conveying samples is arranged on the side wall of the shell, and a purge device for purging inert gas into the sample is installed on the side wall of the shell, and a lifting platform for lifting the sample bottle upward to the purge device is slidably arranged on the side wall of the shell, the purge device includes a fixed box installed on the side wall of the shell, a purge needle is arranged inside the fixed box, and the lower end of the purge needle extends downward to the outside of the fixed box, and a gas tank filled with inert gas is also arranged on the side wall of the shell, and the air inlet of the purge needle is connected to the gas tank by a hose.

[0009] The upper end of the bottom plate is provided with a sample feeding device for conveying samples to the purging device. The feeding device includes a conveyor belt installed on the upper end of the bottom plate. The upper end of the conveyor belt is provided with a plurality of equally spaced placement holes, and sample bottles containing samples are placed in the placement holes.

[0010] As a preferred technical solution of the present invention, the side of the conveyor belt close to the feeding robot arm is a straight structure and is perpendicular to the horizontal movement direction of the feeding robot arm, and the side of the conveyor belt away from the feeding robot arm is composed of a plurality of interconnected U-shaped structures, and two adjacent U-shaped structures are symmetrically distributed; A plurality of rotating shafts for supporting and driving the conveyor belt are rotatably mounted on the upper end of the bottom plate, an intermittent motor is arranged on the side wall of the bottom plate through a motor seat, and an output shaft of the intermittent motor is connected to any rotating shaft through a belt drive.

[0011] As a preferred technical solution of the present invention, the lifting platform is provided with vertically arranged turnover barrels, and the inner wall of the turnover barrel is provided with a plurality of arc-shaped resistance plates for abutting against the outer wall of the sample bottle, a guide spring is installed between the upper end of the arc-shaped resistance plate and the inner wall of the turnover barrel, and a plurality of anti-slip strips equidistantly distributed from top to bottom are provided on one side of the arc-shaped resistance plate close to the axis of the turnover barrel.

[0012] As a preferred technical solution of the present invention, a plurality of through slots corresponding to the positions of the arc-shaped contact plates are provided inside the turnover barrel, a positioning shaft is provided in the through slot, a swing rod is provided on the outer wall of the positioning shaft through a torsion spring rotation sleeve, one end of the swing rod close to the axis of the turnover barrel is an elastic telescopic rod, and the elastic telescopic rod is hinged to the arc-shaped contact plate; A plurality of annularly distributed elastic bands are evenly installed on the inner wall of the turnover barrel. The elastic bands are located below the arc-shaped resistance plate, and a supporting plate is commonly arranged on one side of the plurality of elastic bands close to the axis of the turnover barrel.

[0013] As a preferred technical solution of the present invention, a linkage plate is installed at one end of the swing rod far from the axis of the turnover barrel after extending out of the turnover barrel. A clamping block is arranged at the upper end of the linkage plate. A positioning ring is fixedly sleeved on the outer wall of the turnover barrel and located above the positioning shaft. A plurality of clamping grooves matched with the clamping block are arranged at the lower end of the positioning ring.

[0014] As a preferred technical solution of the present invention, two telescopic columns are symmetrically installed up and down on one side of the arc-shaped abutting plate far from the axis of the turnover barrel. A sliding groove corresponding to the position of the telescopic column is arranged on the inner wall of the turnover barrel. A connecting block which is slidably butted in the sliding groove is installed at one end of the telescopic column far from the arc-shaped abutting plate.

[0015] As a preferred technical solution of the present invention, a cleaning device for cleaning the purge needle is installed at the lower end of the fixed box. The cleaning device includes a circular storage chamber sleeved outside the purge needle. A positioning ring sleeved outside the purge needle is installed on the side wall of the circular storage chamber. The positioning ring is located below the circular storage chamber. A plurality of annularly distributed connecting rods are uniformly penetrated through the positioning ring. A linkage ring is jointly installed at the upper ends of the plurality of connecting rods. An execution unit for cleaning the purge needle is arranged on the linkage ring.

[0016] A positioning pad is sleeved on the upper side of the connecting rod. A return spring sleeved outside the connecting rod is installed between the positioning pad and the positioning ring; A plurality of supporting ears corresponding to the positions of the connecting rods are installed on the outer wall of the positioning ring. Through holes for passing through the connecting rods are arranged on the supporting ears. A plurality of installation grooves are arranged on the inner wall of the through holes. A top contact block is installed in the installation grooves through supporting spring rods. An annular groove matched with the top contact block is arranged on the lower side of the connecting rod.

[0017] As a preferred technical solution of the present invention, the execution unit includes a plurality of auxiliary blocks installed at the upper end of the linkage ring. A liquid storage cavity is arranged inside the auxiliary block. An opening is arranged on one side of the liquid storage cavity close to the purge needle, and a cleaning sponge is installed at the opening. A liquid extraction cylinder communicated with the liquid storage cavity is arranged at the upper end of the liquid storage cavity for quantitatively extracting the cleaning agent in the circular storage chamber.

[0018] In addition, the present invention also provides a purge and trap method, including the following steps: S1: Sample placement: Place the sample bottle containing the sample in the placement hole, and then sequentially convey the sample to the initial position below the feeding robotic arm through the conveyor belt; S2: Sample lifting: The feeding robotic arm takes the sample bottle and places it on the lifting table, and then the lifting table lifts the sample bottle upward to the purge device; S3: Sample purge and trap: An inert gas is introduced into the sample through a purging device, and volatile organic compounds are released from the sample by bubbling; during the purging process of the sample, the volatile organic compounds are captured by the adsorbent in the trap; after purging is completed, the trap is heated to desorb the captured target substances, and finally the desorbed concentrated components are poured into a gas chromatograph for analysis; S4: Sample bottle retrieval: The lifting platform drives the sample bottle to move downward, then the feeding robotic arm takes out the purged and trapped sample bottle and places it in the original placement hole, and then the conveyor belt operates to transport the sample bottle to be purged to the lower part of the feeding robotic arm.

[0019] In summary, the present application includes the following beneficial technical effects: First, the present invention can achieve automatic supply of samples through the conveyor belt, and the feeding robotic arm only needs to complete the two-axis movement in the horizontal and vertical directions, thereby reducing the movement of the feeding robotic arm in the direction perpendicular to the outer shell, reducing its occupied space, and the conveyor belt cooperating with the feeding robotic arm can effectively improve the supply speed of the samples, thereby improving the overall purge and trap efficiency of the samples.

[0020] Second, the present invention can perform multi-directional clamping and limiting on the sample bottle by multiple arc-shaped abutting plates against the outer wall of the sample bottle, and further limit the sample bottle by applying opposite forces to the sample bottle by the supporting plate and the arc-shaped abutting plate at the same time, thereby ensuring the stability of the sample bottle, and the arc-shaped abutting plate can limit sample bottles with different diameters, thereby improving the adaptation range of the present invention, and the sample bottle can be limited by inserting it into the turnover barrel, and the limit can be released by pulling the sample bottle upward, so as to effectively improve the convenience.

[0021] Third, after the sample purge and trap is completed, the turnover barrel drives the sample bottle, positioning ring, support ear, connecting rod, linkage ring, auxiliary block and cleaning sponge to move downward as a whole. The outer wall of the purge needle can be cleaned by the cleaning sponge impregnated with the cleaning agent. When the turnover barrel moves downward, the connecting rod drives the auxiliary block and the cleaning sponge to move upward and reset, so that the purge needle can be cleaned every time a sample purge and trap is completed; thereby, the residual sample on the outer wall of the purge needle can be removed, preventing the residual sample from affecting the analysis purity and data accuracy of subsequent samples, thereby ensuring the analysis accuracy, and avoiding blockage of the purge needle. Description of the Drawings

[0022] The present invention will be further described below with reference to the drawings and embodiments.

[0023] Figure 1 is the structural schematic diagram of the present invention.

[0024] Figure 2 is the structural schematic diagram between the bottom plate, outer shell, feeding robotic arm and sample feeding device of the present invention.

[0025] Figure 3 It is a schematic structural diagram between the purging device and the lifting platform of the present invention.

[0026] Figure 4 It is a schematic structural diagram among the fixed box, the purging needle and the turnover barrel of the present invention.

[0027] Figure 5 It is a schematic internal structural diagram of the turnover barrel of the present invention.

[0028] Figure 6 It is the present invention Figure 5 Partial enlarged view of part A.

[0029] Figure 7 It is a schematic structural diagram between the fixed box and the cleaning device of the present invention.

[0030] Figure 8 It is a schematic structural diagram of the cleaning device of the present invention.

[0031] Figure 9 It is the present invention Figure 8 Partial enlarged view of part B.

[0032] Figure 10 It is a schematic structural diagram among the fixed box, the annular storage chamber, the linkage ring and the execution unit of the present invention.

[0033] Figure 11 It is the present invention Figure 11 Partial enlarged view of part C.

[0034] Figure 12 It is a schematic structural diagram among the sealing plate, the semi-cylindrical barrel, the elastic retaining piece and the sealing strip of the present invention.

[0035] In the figure, 1 is the bottom plate; 2 is the outer shell; 3 is the feeding robotic arm; 4 is the purging device; 41 is the fixed box; 42 is the purging needle; 43 is the gas tank; 5 is the lifting platform; 51 is the turnover barrel; 511 is the positioning shaft; 512 is the swing rod; 513 is the elastic telescopic rod; 514 is the elastic band; 515 is the supporting plate; 516 is the linkage plate; 517 is the clamping block; 518 is the positioning ring; 519 is the clamping groove; 52 is the arc-shaped contact plate; 521 is the telescopic column; 522 is the sliding groove; 523 is the connecting block; 53 is the guiding elastic sheet; 54 is the anti-slip strip; 6 is the sample feeding device; 61 is the conveyor belt; 611 is the rotating shaft; 612 is the intermittent motor; 62 is the placement hole; 63 is the sample bottle; 7 is the cleaning device; 71 is the annular storage chamber; 711 is the sealing plate; 712 is the top extension spring; 713 is the semi-cylindrical barrel; 714 is the elastic retaining piece; 715 is the sealing strip; 72 is the positioning ring; 73 is the connecting rod; 731 is the positioning pad; 732 is the return spring; 733 is the ear; 734 is the supporting spring rod; 735 is the top contact block; 736 is the annular groove; 74 is the linkage ring; 75 is the execution unit; 751 is the auxiliary block; 752 is the liquid storage chamber; 753 is the cleaning sponge; 754 is the liquid extraction cylinder. Detailed implementation manners

[0036] The following Figure 1-12 will describe the embodiments of the present invention in detail with reference to the accompanying drawings.

[0037] The embodiments of the present application disclose a purge and trap analyzer. It should be noted that the purge and trap analyzer of the present application is mainly used in the process of purging and trapping samples. In terms of technical effects, it can automatically supply samples, and can limit the sample bottle 63 during the purge and trap process to ensure the stability of the sample bottle 63. Especially during the process of limiting the sample bottle 63, it can limit the sample bottle 63 in multiple directions, and can further limit the sample bottle 63 by applying opposite forces in the up and down directions to the sample bottle 63, and can limit sample bottles 63 with different diameters, thereby improving the adaptation range of the present application. Further, the purge and trap analyzer of the present application can also clean the purge needle 42 after each sample purge and trap is completed, so as to remove the sample residues on the outer wall of the purge needle 42, prevent the residual samples from affecting the analysis purity and data accuracy of subsequent samples, and thus ensure the analysis accuracy, and can avoid causing blockage of the purge needle 42.

[0038] Refer to Figure 1 、 Figure 2 and Figure 3As shown in the figure, a purge and trap instrument includes a bottom plate 1. An L-shaped housing 2 is provided at the upper end of the bottom plate 1. A feeding robotic arm 3 for transporting samples is provided on the side wall of the housing 2. And a purging device 4 for purging inert gas into the samples is installed on the side wall of the housing 2. The feeding robotic arm 3 and the purging device 4 are located in the same plane. A lifting table 5 for lifting the sample bottle 63 upward to the purging device 4 is slidably provided on the side wall of the housing 2. It is characterized in that: the purging device 4 includes a fixed box 41 installed on the side wall of the housing 2. A purging needle 42 is provided inside the fixed box 41. The lower end of the purging needle 42 extends downward outside the fixed box 41. An inert gas cylinder 43 is also provided on the side wall of the housing 2. The air inlet of the purging needle 42 is connected to the inert gas cylinder 43 through a hose. The inert gas cylinder 43 is used to transport inert gas to the purging needle 42 through the hose.

[0039] Further, in this embodiment, a sample feeding device 6 for transporting the sample to the purging device 4 is provided at the upper end of the bottom plate 1. The feeding device includes a conveyor belt 61 installed at the upper end of the bottom plate 1. A plurality of equally spaced placement holes 62 are opened at the upper end of the conveyor belt 61. A sample bottle 63 containing the sample is placed in the placement hole 62.

[0040] In the specific implementation process, the sample bottle 63 containing the sample is placed in the placement hole 62. Subsequently, the sample is sequentially transported to the initial position below the feeding robotic arm 3 through the conveyor belt 61. Then the feeding robotic arm 3 picks up the sample bottle 63 and places it on the lifting table 5. Then the lifting table 5 lifts the sample bottle 63 upward to the purging device 4, so that the purging needle 42 is inserted into the sample bottle 63. The purging needle 42 introduces inert gas into the sample, and volatile organic compounds are released from the sample through bubbling; during the purging of the sample, the valve core is rotated to direct the volatile organic compounds to the trap (prior art, not shown in the figure). The volatile organic compounds are captured by the adsorbent in the trap. After the purging is completed, the trap is heated to desorb the captured target substances. Finally, the desorbed concentrated components are poured into a gas chromatograph for analysis; then the lifting table 5 drives the sample bottle 63 to move downward. Subsequently, the feeding robotic arm 3 takes out the purged and trapped sample bottle 63 and places it in the original placement hole 62. Then the conveyor belt 61 operates to transport the sample bottle 63 to be purged below the feeding robotic arm 3.

[0041] It should be noted that in this embodiment, the gas flow path is switched through a six-way valve instead of moving the sample bottle 63 to achieve stage conversion, that is, the purging, trapping, and desorbing operations can be sequentially completed by changing the gas flow path. This design ensures the analysis speed and sensitivity.

[0042] Refer to Figure 2As shown, in order to improve the purging efficiency, the conveyor belt 61 is used to replace the traditional sample tray in this embodiment, so as to realize the automatic transmission of the sample bottle 63 and the purging and capturing efficiency. Specifically, the side of the conveyor belt 61 close to the feeding robot arm 3 is a straight structure and is perpendicular to the horizontal movement direction of the feeding robot arm 3, and the side of the conveyor belt 61 away from the feeding robot arm 3 is composed of a plurality of interconnected U-shaped structures, and the two adjacent U-shaped structures are symmetrically distributed.

[0043] Furthermore, in this embodiment, a plurality of rotating shafts 611 for supporting and transmitting the transmission belt 61 are rotatably installed on the upper end of the base plate 1, and an intermittent motor 612 is provided on the side wall of the base plate 1 through a motor seat, and the output shaft of the intermittent motor 612 is connected to any rotating shaft 611 through a belt drive.

[0044] During the specific implementation process, the intermittent motor 612 is started, and the intermittent motor 612 drives the conveyor belt 61 to operate through the rotating shaft 611, so that the conveyor belt 61 transports the sample bottle 63 containing the sample to the initial position of the feeding robot arm 3, so that the feeding robot arm 3 can take the sample bottle 63; at this time, the intermittent motor 612 is suspended, and after the sample purging and capturing is completed, the feeding robot arm 3 takes out and puts the sample bottle 63 back, and the intermittent motor 612 drives the conveyor belt 61 to resume operation, so as to transport the next sample bottle 63 to be purged to the bottom of the feeding robot arm 3, thereby realizing the automatic supply of samples.

[0045] In addition, it should be noted that the feeding robot arm 3 used in this embodiment only needs to complete biaxial movement in the horizontal and vertical directions, and does not need to move in a direction perpendicular to the outer shell 2, thereby reducing the movement range of the feeding robot arm 3 and reducing its occupied space. The conveyor belt 61 cooperates with the feeding robot arm 3 to effectively increase the sample supply speed, thereby improving the overall purging and capture efficiency of the sample.

[0046] Reference Figure 4 , Figure 5 and Figure 6 As shown, since different samples use sample bottles 63 of different volumes, for example, the volume of the sample bottle 63 required for a liquid sample is smaller than that required for a solid sample, and the diameters of the sample bottles 63 of different volumes are different, the lifting platform 5 in this embodiment can lift the sample bottles 63 of different diameters. Based on this, in this embodiment, the lifting platform 5 is provided with vertically arranged turnover barrels 51 inside, and a plurality of arc-shaped abutting plates 52 for abutting against the outer wall of the sample bottle 63 are installed on the inner wall of the turnover barrel 51, and a guide spring plate 53 is installed between the upper end of the arc-shaped abutting plate 52 and the inner wall of the turnover barrel 51. The guide spring plate 53 is elastic and can undergo elastic deformation under force, and a plurality of anti-slip strips 54 equidistantly distributed from top to bottom are provided on one side of the arc-shaped abutting plate 52 close to the axis of the turnover barrel 51.

[0047] Further, in this embodiment, a plurality of through grooves corresponding to the positions of the arc-shaped abutting plates 52 are formed inside the turnover barrel 51. A positioning shaft 511 is arranged in the through grooves. A swing rod 512 is rotatably sleeved on the outer wall of the positioning shaft 511 through a torsion spring. One end of the swing rod 512 close to the axis of the turnover barrel 51 is an elastic telescopic rod 513, and the elastic telescopic rod 513 is hinged to the arc-shaped abutting plate 52. The torsion spring always applies a torsional force to the elastic telescopic rod 513, so that the side of the elastic telescopic rod 513 close to the axis of the turnover barrel 51 always drives the arc-shaped abutting plate 52 to lift upward in the initial state, and the elastic telescopic rod 513 itself has elasticity, so that the elastic telescopic rod 513 pushes the arc-shaped abutting plate 52 outwards towards the side close to the axis of the turnover barrel 51 in the initial state. A plurality of annularly distributed elastic bands 514 are uniformly installed on the inner wall of the turnover barrel 51. The elastic bands 514 are located below the arc-shaped abutting plates 52. A supporting plate 515 is jointly arranged on the sides of the plurality of elastic bands 514 close to the axis of the turnover barrel 51. The elastic bands 514 have elasticity and can undergo elastic deformation under a force state.

[0048] Furthermore, in this embodiment, a linkage plate 516 is installed at one end of the swing rod 512 far from the axis of the turnover barrel 51 after extending out of the turnover barrel 51. A clamping block 517 is arranged at the upper end of the linkage plate 516. A positioning ring 518 is fixedly sleeved on the outer wall of the turnover barrel 51 above the positioning shaft 511. A plurality of clamping grooves 519 matched with the clamping blocks 517 are formed at the lower end of the positioning ring 518.

[0049] In the specific implementation process, when the feeding robotic arm 3 places the sample bottle 63 into the turnover barrel 51, the sample bottle 63 first inserts into the turnover barrel 51 and extrudes the plurality of arc-shaped abutting plates 52 outwards. The arc-shaped abutting plates 52 drive the elastic telescopic rods 513 to adaptively contract. As the sample bottle 63 continues to press down, the sample bottle 63 comes into contact with the anti-slip strips 54 on the side walls of the arc-shaped abutting plates 52. The cooperation between the anti-slip strips 54 and the sample bottle 63 can drive the arc-shaped abutting plates 52 to move downwards. When the sample bottle 63 is inserted to the bottom of the turnover barrel 51, it abuts against the upper end of the supporting plate 515 and presses down the supporting plate 515. The elastic bands 514 are stretched under force and apply an upward reaction force to the supporting plate 515 and the sample bottle 63. At this time, the arc-shaped abutting plates 52 drive the elastic telescopic rods 513 to incline downwards. The arc-shaped abutting plates 52 apply a downward reaction force to the sample bottle 63 under the action of the elastic telescopic rods 513, so that the plurality of arc-shaped abutting plates 52 all abut against the outer wall of the sample bottle 63, thereby clamping and limiting the sample bottle 63 in multiple directions. Moreover, the sample bottle 63 can be further limited by the supporting plate 515 and the arc-shaped abutting plates 52, so as to ensure the stability of the sample bottle 63. And the arc-shaped abutting plates 52 can limit the sample bottles 63 with different diameters, thereby improving the adaptation range of the present invention.

[0050] In addition, when the arc-shaped abutting plate 52 drives the elastic telescopic rod 513 to tilt downward, the elastic telescopic rod 513 drives the linkage plate 516 and the clamping block 517 to move upward as a whole through the swing rod 512, so that the clamping block 517 is clamped in the clamping groove 519, thereby being able to limit the swing rod 512 and the elastic telescopic rod 513 in the tilted state, enabling the swing rod 512 to overcome the torsional force of the torsion spring, and preventing the swing rod 512 from driving the elastic telescopic rod 513 and the arc-shaped abutting plate 52 to reset upward, which may affect the limiting effect on the sample bottle 63.

[0051] After the purge and trap is completed, the feeding robotic arm 3 can simply pull the sample bottle 63 upward. When the sample bottle 63 moves upward, it drives the arc-shaped abutting plate 52 to move upward. The arc-shaped abutting plate 52 drives the clamping block 517 to disengage from the clamping groove 519 through the elastic telescopic rod 513 and the swing rod 512, thereby releasing the limiting effect on the swing rod 512 and enabling the arc-shaped abutting plate 52 to reset, facilitating the limiting process for the next sample bottle 63. In addition, inserting the sample bottle 63 into the turnover barrel 51 can obtain the limit of the arc-shaped abutting plate 52, and pulling the sample bottle 63 upward can release the limit, thereby effectively improving the convenience.

[0052] Continue to refer to Figure 6 As shown, it should be supplemented that, in order to ensure the stability and vertical state of the arc-shaped abutting plate 52 during the lifting process, in this embodiment, two telescopic columns 521 are symmetrically installed up and down on the side of the arc-shaped abutting plate 52 away from the axis of the turnover barrel 51. A sliding groove 522 corresponding to the position of the telescopic column 521 is provided on the inner wall of the turnover barrel 51. A connecting block 523 that is slidably docked in the sliding groove 522 is installed at one end of the telescopic column 521 away from the arc-shaped abutting plate 52. The telescopic column 521 is a multi-section telescopic structure, and a damping is provided between adjacent two-section telescopic structures to slow down the extension and contraction speed of the telescopic column 521. When the elastic telescopic rod 513 pushes the arc-shaped abutting plate 52 toward the side close to the axis of the turnover barrel 51, the arc-shaped abutting plate 52 can be restricted through the telescopic column 521 and the connecting block 523, so that equal restricting forces are applied to the upper and lower sides of the arc-shaped abutting plate 52, and thus the arc-shaped abutting plate 52 can always maintain a vertical state, further increasing the contact area between the arc-shaped abutting plate 52 and the sample bottle 63, and further improving the stability of the sample bottle 63 during the ascending, descending, and purging processes.

[0053] Refer to Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 and Figure 11As shown, after the purge operation is completed, the surface of the purge needle 42 is prone to adhere to the sample, which is easy to affect the purity of the subsequent samples, resulting in a false positive result, and the long-term residual sample may clog the pinhole of the purge needle 42, especially the sample containing particulate matter or a high-boiling point matrix, thereby reducing the purge efficiency and effect. Based on this, in this embodiment, the outer wall of the purge needle 42 can be cleaned accordingly after the purge operation is completed. Specifically, a cleaning device 7 for cleaning the purge needle 42 is installed at the lower end of the fixed box 41. The cleaning device 7 includes a An annular storage chamber 71 is installed at the lower end of the fixed box 41. A liquid filling pipe for replenishing the cleaning agent is installed on the side wall of the annular storage chamber 71. A positioning ring 72 is installed on the side wall of the outer shell 2 and is sleeved on the outside of the purge needle 42. The positioning ring 72 is located below the annular storage chamber 71, and the inner diameter of the positioning ring 72 is larger than the outer diameter of the turnover barrel 51. A plurality of annularly distributed connecting rods 73 are evenly penetrated on the positioning ring 72. A linkage ring 74 is commonly installed on the upper ends of the plurality of connecting rods 73. An execution unit 75 for cleaning the purge needle 42 is provided on the linkage ring 74.

[0054] Furthermore, in the present embodiment, a positioning pad 731 is sleeved on the upper side of the connecting rod 73, and a return spring 732 is installed between the positioning pad 731 and the positioning ring 72 and sleeved on the outside of the connecting rod 73; since the positioning ring 72 does not move, the return spring 732 always applies an upward lifting force to the positioning pad 731 and the connecting rod 73, so that the connecting rod 73 drives the actuator 75 to the highest position through the linkage ring 74 in the initial state; a plurality of corresponding connecting rod 73 positions are installed on the outer wall of the positioning ring 518 The ear 733 is provided with a through hole for passing the connecting rod 73, and the inner wall of the through hole is provided with a plurality of mounting grooves, in which a top contact block 735 is installed via a supporting spring rod 734, and an annular groove 736 matching the top contact block 735 is provided on the lower side of the connecting rod 73, and the cross-sections of the top contact block 735 and the annular groove 736 are both triangular structures, and the supporting spring rod 734 always applies a pushing force to the top contact block 735, so that the top contact block 735 is pushed out to the side close to the axis of the connecting rod 73 in the initial state.

[0055] Furthermore, in this embodiment, the execution unit 75 includes a plurality of auxiliary blocks 751 installed at the upper end of the linkage ring 74, and a liquid storage chamber 752 is provided inside the auxiliary block 751. The liquid storage chamber 752 is provided with an opening on the side close to the purge needle 42, and a cleaning sponge 753 is installed at the opening. A liquid collection cylinder 754 connected to the liquid storage chamber 752 is provided at the upper end thereof for quantitatively removing the cleaning agent in the annular storage chamber 71.

[0056] It should be supplemented that a plurality of through holes corresponding to the position of the liquid extraction cylinder 754 are opened at the lower end of the annular storage chamber 71. A horizontal receiving groove is opened in the through hole. Two sealing plates 711 that are engaged with each other are symmetrically slidably arranged along the axis of the through hole inside the horizontal receiving groove. A top spring 712 is installed between the sealing plate 711 and the inner wall of the horizontal receiving groove. The top spring 712 always applies a pushing force to the sealing plate 711, so that the sealing plate 711 moves toward the side close to the axis of the through hole in the initial state, so that the two sealing plates 711 are docked with each other to close the through hole and prevent the cleaning agent in the annular storage chamber 71 from leaking out. A semi-cylindrical barrel 713 is installed at the lower end of the sealing plate 711. The lower end of the semi-cylindrical barrel 713 gradually inclines toward the side away from the axis of the through hole. An elastic baffle 714 is installed between the two semi-cylindrical barrels 713 at the same through hole. The elastic baffle 714 can elastically deform under the action of an external force to guide the cleaning agent in the area in cooperation with the two semi-cylindrical barrels 713 when the sealing plate 711 is opened, and prevent the cleaning agent from flowing out through the gap between the two semi-cylindrical barrels 713.

[0057] In the initial state, the linkage ring 74 drives the auxiliary block 751 to be in the highest position. The auxiliary block 751 drives the liquid extraction cylinder 754 to be inserted between the two semi-cylindrical barrels 713, so as to push the two semi-cylindrical barrels 713 out to both sides, thereby releasing the sealing effect of the sealing plate 711 on the through hole, so that the cleaning agent in the annular storage chamber 71 flows into the liquid storage cavity 752 through the through hole, the semi-cylindrical barrel 713 and the liquid extraction cylinder 754 in sequence. The cleaning agent in the liquid storage cavity 752 is impregnated inside the cleaning sponge 753 through the opening.

[0058] In the specific implementation process, when the turnover bucket 51 drives the sample bottle 63 to move up for purging, the turnover bucket 51 drives the positioning ring 518 and the lugs 733 on its outer wall to move synchronously. Since the positioning ring 72 and the connecting rod 73 do not move during this process, relative movement occurs between the lug 733 and the connecting rod 73; when the through hole on the lug 733 is sleeved on the lower end of the connecting rod 73, the lug 733 drives the top contact block 735 to abut against the annular groove 736. The elasticity of the support spring rod 734 is greater than that of the return spring 732. Therefore, through the cooperation between the top contact block 735 and the annular groove 736, the lug 733 can drive the connecting rod 73 to move; after the sample purge and capture are completed, the turnover bucket 51 drives the sample bottle 63 to move down, so that the turnover bucket 51 drives the connecting rod 73 to move down synchronously through the positioning ring 518 and the lug 733. The connecting rod 73 drives the linkage ring 74, the auxiliary block 751 and the cleaning sponge 753 to move down as a whole. During this period, the outer wall of the purge needle 42 can be cleaned by the cleaning sponge 753 impregnated with the cleaning agent, so that the residual sample on the outer wall of the purge needle 42 can be removed, preventing the residual sample from affecting the analysis purity and data accuracy of the subsequent sample, thereby ensuring the analysis accuracy, and avoiding blockage of the purge needle 42.

[0059] When the connecting rod 73 moves down to the lowest position, the positioning pad 731 on the outer wall of the connecting rod 73 abuts against the upper end of the positioning ring 72, causing the connecting rod 73 to be unable to move down further. At this time, the turnover barrel 51 drives the linkage ring 74 and the ear 733 to continue moving down, so that the ear 733 can drive the top contact block 735 to disengage from the annular groove 736, and the connecting rod 73 drives the auxiliary block 751 and the cleaning sponge 753 to move up and reset integrally under the action of the return spring 732. Repeating the above steps can clean the purge needle 42 every time a sample is purged and trapped.

[0060] Refer to Figure 12 As shown, it should be noted that two sealing strips 715 are symmetrically installed on one side of one sealing plate 711 close to the axis of the through hole along the semi-cylindrical barrel 713, and a groove for engaging with the sealing strip 715 is provided on one side of the other sealing plate 711 close to the axis of the through hole. That is to say, no sealing strip 715 is installed at the center of the semi-cylindrical barrel 713 where the two sealing plates 711 are located. Therefore, when the two sealing plates 711 move away from each other, the gap is first opened at the center of the semi-cylindrical barrel 713 where the two sealing plates 711 are located, and both sides of the sealing plate 711 away from the semi-cylindrical barrel 713 are still sealed against the through hole under the action of the sealing strip 715, thus avoiding the waste caused by the leakage of the cleaning agent.

[0061] In addition, the present invention also provides a purge and trap method, including the following steps: S1: Sample placement: Place the sample bottle 63 containing the sample in the placement hole 62, and then sequentially transport the sample to the initial position below the feeding robotic arm 3 through the conveyor belt 61.

[0062] S2: Sample lifting: Start the intermittent motor 612. The intermittent motor 612 drives the conveyor belt 61 to operate through the rotating shaft 611, so that the conveyor belt 61 transports the sample bottle 63 containing the sample to the initial position of the feeding robotic arm 3 for the feeding robotic arm 3 to pick up the sample bottle 63. At this time, the intermittent motor 612 pauses, and the feeding robotic arm 3 picks up the sample bottle 63 and places it in the turnover barrel 51 on the lifting table 5. The sample bottle 63 is multi-directionally clamped and limited under the action of a plurality of arc-shaped abutting plates 52, and the sample bottle 63 can be further limited by applying opposite forces to the sample bottle 63 through the supporting plate 515 and the arc-shaped abutting plates 52, thereby ensuring the stability of the sample bottle 63.

[0063] S3: Sample purge and trap: The turnover barrel 51 drives the sample bottle 63 to move upward, so that the purge needle 42 is inserted into the sample bottle 63. The purge needle 42 passes inert gas into the sample, and volatile organic compounds are released from the sample by bubbling. During the purge of the sample, the valve core is rotated to direct the volatile organic compounds into the trap, and the volatile organic compounds are captured by the adsorbent in the trap. After the purge is completed, the trap is heated to desorb the captured target substances, and finally the desorbed concentrated components are poured into the gas chromatograph for analysis.

[0064] S4: Recovery of the sample bottle 63: After the purge and trap is completed, the turnover barrel 51 and the sample bottle 63 are driven by the lifting platform 5 to move downward. The feeding robotic arm 3 pulls out the sample bottle 63 upward and places it in the original placement hole 62. Then the conveyor belt 61 operates to convey the sample bottle 63 to be purged to the lower part of the feeding robotic arm 3.

[0065] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

[0066] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A purge trap instrument, comprising a base plate (1), a housing (2) disposed at the upper end of the base plate (1), a feeding mechanical arm (3) for conveying a sample disposed on the side wall of the housing (2), a purge device (4) for purging an inert gas into the sample installed on the side wall of the housing (2), a lifting platform (5) for lifting a sample bottle (63) upward to the purge device (4) slidably disposed on the side wall of the housing (2), characterized in that: The purge device (4) comprises a fixed box (41) mounted on the side wall of the housing (2), a purge needle (42) is arranged inside the fixed box (41), the lower end of the purge needle (42) extends downward to the outside of the fixed box (41), and a gas tank (43) filled with inert gas is also arranged on the side wall of the housing (2), and the gas inlet of the purge needle (42) is connected to the gas tank (43) via a hose; A sample delivery device (6) for delivering the sample to the purge device (4) is provided at the upper end of the base plate (1), the delivery device comprising a conveyor belt (61) mounted at the upper end of the base plate (1), a plurality of equally spaced placement holes (62) being provided at the upper end of the conveyor belt (61), and sample bottles (63) containing the sample being placed in the placement holes (62).

2. A purge-and-trap instrument according to claim 1, characterized in that: The side of the conveyor belt (61) close to the feeding robot arm (3) is a straight structure and is perpendicular to the horizontal movement direction of the feeding robot arm (3), and the side of the conveyor belt (61) away from the feeding robot arm (3) is composed of a plurality of interconnected U-shaped structures, and two adjacent U-shaped structures are symmetrically distributed; A plurality of rotating shafts (611) for supporting and transmitting the transmission belt (61) are rotatably mounted on the upper end of the bottom plate (1); an intermittent motor (612) is arranged on the side wall of the bottom plate (1) via a motor seat; an output shaft of the intermittent motor (612) is connected to any rotating shaft (611) via a belt transmission.

3. A purge-and-trap instrument according to claim 2, characterized in that: The lifting platform (5) is provided with vertically arranged turnover barrels (51) inside, and a plurality of arc-shaped abutment plates (52) for abutting against the outer wall of the sample bottle (63) are installed on the inner wall of the turnover barrel (51), and a guide spring sheet (53) is installed between the upper end of the arc-shaped abutment plate (52) and the inner wall of the turnover barrel (51), and a plurality of anti-slip strips (54) equidistantly distributed from top to bottom are provided on one side of the arc-shaped abutment plate (52) close to the axis of the turnover barrel (51).

4. A purge-and-trap instrument according to claim 3, characterized in that: The turnover barrel (51) is provided with a plurality of through slots corresponding to the positions of the arc-shaped abutment plates (52), and a positioning shaft (511) is provided in the through slots. A swing rod (512) is rotatably sleeved on the outer wall of the positioning shaft (511) via a torsion spring, and one end of the swing rod (512) close to the axis of the turnover barrel (51) is an elastic telescopic rod (513), and the elastic telescopic rod (513) is hinged to the arc-shaped abutment plates (52); A plurality of annularly distributed elastic bands (514) are evenly installed on the inner wall of the turnover barrel (51), the elastic bands (514) are located below the arc-shaped abutment plate (52), and a support plate (515) is commonly provided on one side of the plurality of elastic bands (514) close to the axis of the turnover barrel (51).

5. A purge-and-trap instrument according to claim 4, characterized in that: One end of the swing rod (512) away from the axis of the turnover barrel (51) extends out of the turnover barrel (51) and is then mounted with a linkage plate (516). A clamping block (517) is disposed at the upper end of the linkage plate (516). A positioning ring (518) located above the positioning shaft (511) is provided on the outer wall fixed sleeve of the turnover barrel (51). A plurality of clamping grooves (519) cooperating with the clamping block (517) are provided at the lower end of the positioning ring (518).

6. A purge-and-trap instrument according to claim 5, characterized in that: Two telescopic columns (521) are symmetrically mounted on one side of the arc-shaped abutment plate (52) away from the axis of the turnover barrel (51), a sliding groove (522) corresponding to the position of the telescopic columns (521) is opened on the inner wall of the turnover barrel (51), and a connecting block (523) slidably docked in the sliding groove (522) is mounted on one end of the telescopic column (521) away from the arc-shaped abutment plate (52).

7. A purge-and-trap instrument according to claim 6, characterized in that: A cleaning device (7) for cleaning the purge needle (42) is installed at the lower end of the fixed box (41), the cleaning device (7) comprising an annular storage chamber (71) sleeved on the outside of the purge needle (42), a positioning ring (72) sleeved on the outside of the purge needle (42) is installed on the side wall of the housing (2), the positioning ring (72) is located below the annular storage chamber (71), a plurality of annularly distributed connecting rods (73) are evenly penetrated on the positioning ring (72), a linkage ring (74) is commonly installed on the upper ends of the plurality of connecting rods (73), and an execution unit (75) for cleaning the purge needle (42) is arranged on the linkage ring (74).

8. A purge-and-trap instrument according to claim 7, characterized in that: A positioning pad (731) is sleeved on the upper side of the connecting rod (73), and a return spring (732) sleeved on the outside of the connecting rod (73) is installed between the positioning pad (731) and the positioning ring (72); The outer wall of the positioning ring (518) is provided with a plurality of ears (733) corresponding to the positions of the connecting rod (73); a through hole for passing the connecting rod (73) is provided on the ear (733); a plurality of mounting grooves are provided on the inner wall of the through hole; a top contact block (735) is installed in the mounting groove via a supporting spring rod (734); and an annular groove (736) matching the top contact block (735) is provided on the lower side of the connecting rod (73).

9. A purge-and-trap instrument according to claim 7, characterized in that: The execution unit (75) comprises a plurality of auxiliary blocks (751) mounted on the upper end of the linkage ring (74); a liquid storage chamber (752) is provided inside the auxiliary block (751); an opening is provided on a side of the liquid storage chamber (752) close to the purge needle (42); a cleaning sponge (753) is mounted at the opening; a liquid extraction cylinder (754) is provided at the upper end of the liquid storage chamber (752) and is in communication with the liquid storage chamber (752) for quantitatively extracting the cleaning agent in the annular storage chamber (71).

10. A purge and trap method, using a purge and trap apparatus as claimed in any one of claims 1 to 9, characterized in that: The purge and trap method includes the following steps: S1: Sample placement: placing a sample bottle (63) containing a sample in the placement hole (62), and then transporting the sample to the initial position below the feeding robot arm (3) in sequence via the conveyor belt (61); S2: Sample lifting: The feeding robot arm (3) takes the sample bottle (63) and places it on the lifting platform (5), and then lifts the sample bottle (63) upward to the purge device (4) through the lifting platform (5); S3: Sample purging and trapping: Inert gas is introduced into the sample through the purging device (4), and volatile organic compounds are released from the sample by bubbling; during the purging process, the volatile organic compounds are captured by the adsorbent in the trap; after the purging is completed, the desorbed concentrated components are poured into the gas chromatograph for analysis; S4: Retracting the sample bottle (63): The sample bottle (63) is moved downward by the lifting platform (5), and then the feeding robot arm (3) takes out the sample bottle (63) after the purge and capture and places it in the original storage hole (62). Then the conveyor belt (61) is operated to transport the sample bottle (63) to be purged to the bottom of the feeding robot arm (3).

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