Graphite pipe and flameless atomization analysis device

Abstract

The utility model provides a graphite tube and flameless atomization analysis device, including graphite tube body, support guide subassembly and platform, the platform is provided in the graphite tube body and is used for placing the sample, the platform bottom surface is provided with the support guide subassembly that is provided on the graphite tube body inner wall and is in sliding connection, utilizes the laser to directly irradiate and heat the sample, and the graphite tube body is fixed on the platform. When the number of times of detection is increased, the top surface of the platform where the sample is placed is aged, the platform can slide along the axial direction of the graphite pipe body, the sample is placed by using the top surface of the unaged platform, the atomization process is continued, the service life of the graphite pipe is prolonged, and the influence of sample residue on an analysis result can be avoided by replacing the top surface of the aged platform; the analysis precision is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of atomic absorption spectrum analysis, and particularly relates to a graphite tube and a flameless atomization analysis device. Background Art

[0002] Flameless atomic absorption spectrometry is a sensitive technique used for elemental analysis. Its detection principle is based on the fact that the element to be measured in the sample is atomized at high temperature to form gaseous ground-state atoms. These atoms selectively absorb characteristic radiation from a specific light source, and the degree of absorption is proportional to the concentration of the element to be measured.

[0003] Graphite tubes are generally used as graphite tubes. By energizing the graphite tube, the tube wall heats up due to its own resistance and the current flowing through it. The high-temperature graphite tube radiates heat to the sample, which absorbs the heat and undergoes atomization. Although graphite tubes are resistant to high temperatures, they also have a service life, ranging from dozens to hundreds of times depending on the processing technology, the atomization temperature of the element to be tested, and the heating hold time. With increasing frequency of use, the surface of the graphite tube becomes pitted, similar to the structure of activated carbon. This makes it possible for the sample to be trapped in its structure during atomization, forming refractory carbides. After the graphite tube cools, these carbides accumulate on its inner surface. When they accumulate to a certain level, they will produce a visible deviation in the test results, which is called the memory effect. The memory effect also accelerates the degradation of the graphite tube. Utility Model Content

[0004] In response to the problems existing in the prior art, the utility model provides a graphite tube and a flameless atomization analysis device. A sliding platform is set in the atomizer body, and a laser directly heats the sample placed on the top surface of the platform. When the top surface of the platform where the sample is located ages, the platform is moved a certain distance along the axial direction of the graphite tube body, and the sample is placed on the top surface of the platform that has not aged, and the atomization process is continued, thereby extending the service life of the graphite tube, reducing the generation of carbides, and helping to reduce the memory effect.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A graphite tube comprises: a graphite tube body with a hollow interior, a support and guide assembly, and a platform; the graphite tube body is provided with an injection hole, and the platform is located on the graphite tube body and is used to carry a sample introduced through the injection hole; the support and guide assembly is arranged on the inner wall of the graphite tube body, and the bottom surface of the platform is slidably connected to the support and guide assembly, and the support and guide assembly is used to support the platform and can guide the platform to slide along the axial direction of the graphite tube body.

[0007] In some embodiments, the support guide assembly includes: two support rails, and the two support rails are symmetrically arranged on the inner wall of the graphite tube body along the axis of the graphite tube body, and have the same relative height.

[0008] In some embodiments, the support guide assembly includes: a plurality of support feet arranged on the inner wall of the graphite tube body, the plurality of support feet are divided into two rows, the two rows of support feet are symmetrically arranged along the axis of the graphite tube body, and the relative heights are consistent; each row of support feet is evenly distributed along the axis of the graphite tube body.

[0009] In some embodiments, a groove is provided on the top surface of the platform, and the groove is used to place the sample introduced through the injection hole.

[0010] In some embodiments, the platform is made of graphite, tungsten, tantalum, or special ceramics.

[0011] In some embodiments, the graphite tube body is made of graphite, tungsten, tantalum, or special ceramics.

[0012] In some embodiments, the platform is provided with a plurality of cutting grooves along its length, and adjacent cutting grooves are equidistantly arranged and parallel to each other.

[0013] The utility model also provides a flameless atomization analysis device, comprising: the above-mentioned graphite tube, a laser irradiator, a temperature detector and a controller; the laser irradiator is used to emit a laser beam to irradiate and heat the sample until it is atomized; the temperature detector is used to detect the temperature of the sample; the size of the injection hole is suitable for allowing the sample and the laser beam to pass through; the laser irradiator and the temperature detector are both controlled and connected to the controller, and the controller controls the opening and closing of the laser irradiator and the laser parameter value according to the temperature value detected by the temperature detector.

[0014] In some embodiments, the flameless atomization analysis device further includes: a graphite furnace, a fixing assembly, a light source emitter and a light absorption detector, wherein the graphite furnace has an inner cavity for accommodating the graphite tube, and the graphite tube is detachably connected to the inner wall of the graphite furnace through the fixing assembly; the light source emitter is used to emit a detection light beam of a specific wavelength to irradiate the atomized sample in the graphite tube, and the light path of the detection light beam is located at the central axis of the graphite tube; the light path of the detection light beam is staggered with the light path of the laser beam; the light absorption detector is used to detect the degree of change in the light intensity value of the detection light beam after being absorbed by the element to be measured in the sample.

[0015] In some embodiments, the fixing assembly includes: a first fixing member and a second fixing member, one end of the graphite tube body is detachably connected to the inner wall of the graphite furnace through the first fixing member, and the other end of the graphite tube body is detachably connected to the inner wall of the graphite furnace through the second fixing member; or, the fixing assembly is a sleeve, the sleeve is sleeved on the outer wall of the graphite tube body, and the outer wall of the sleeve is detachably connected to the inner wall of the graphite furnace.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The graphite tube provided by the present invention is provided with a slidable platform inside. The sample is placed on the top surface of the platform and a laser beam is used to directly irradiate and heat the sample. As the number of tests increases, the top surface of the platform where the sample is placed ages. The platform can be slid along the axial direction of the graphite tube body, and the sample is placed on the unaged top surface of the platform to continue the atomization process, thereby extending the service life of the platform and the graphite tube. Using the unaged top surface of the platform can also avoid the influence of sample residue on the analysis results, thereby improving the analysis accuracy.

[0018] 2. When the entire platform ages, it can be directly replaced with a new one without replacing a new graphite tube. The original graphite tube can be used, which saves the testing investment cost. In addition, the processing difficulty of the platform is small, saving processing costs.

[0019] 3. The utility model provides a plurality of cutting grooves on the platform. When part of the surface of the platform is aged, the aged platform can be removed by breaking or cutting the cutting grooves near the surface of the aged platform, and the unaged platform can be retained for continued use, thereby avoiding interference of the aged platform with the detection and analysis process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 A schematic diagram of the structure of the graphite tube provided by the utility model;

[0022] Figure 2 This is an axial cross-sectional view of the graphite tube provided by the utility model;

[0023] Figure 3 A schematic diagram of the structure of the support rail provided by the utility model;

[0024] Figure 4 A radial cross-sectional view of the support rail provided by the present utility model;

[0025] Figure 5 A schematic diagram of the structure of the support foot provided by the utility model;

[0026] Figure 6A radial cross-sectional view of the support foot provided by the present utility model;

[0027] Figure 7 This is a schematic structural diagram of the flameless atomization analysis device provided by the present invention.

[0028] The meanings of the symbols in the accompanying drawings are as follows:

[0029] 1—graphite tube body; 2—injection hole; 3—platform; 4—groove; 5—support rail; 6—support foot; 7—sample; 8—casing; 9—laser beam; 10—indicator beam; 11—detection beam. DETAILED DESCRIPTION

[0030] The present invention will be further explained in detail below in conjunction with the drawings and descriptions of specific embodiments. However, the following descriptions including the embodiments are only intended to enable ordinary technicians in the technical field to which the present invention belongs to more clearly understand the principles and essence of the present invention, and do not mean to limit the present invention in any form.

[0031] Example 1

[0032] The utility model addresses the problems in the prior art of overall heating of the graphite tube resulting in a shortened service life of the graphite tube, and the increased atomization process causing a memory effect that affects the analysis results. A new heating method is adopted in which a laser beam 9 is used to directly irradiate and heat the sample 7 to achieve localized heating. Only the sample 7 is heated, and the overall graphite tube does not heat up, thereby extending the service life of the graphite tube.

[0033] Furthermore, Figure 1 and Figure 2 As shown, the graphite tube provided by the present invention includes: a graphite tube body 1 with a hollow interior, a support guide assembly and a platform 3. The graphite tube body 1 is provided with an injection hole 2. The platform 3 is located inside the graphite tube body 1 for carrying a sample 7. After the injector absorbs the sample, it passes through the injection hole 2 and extends into the graphite tube body 1 to release the sample 7 on the platform 3.

[0034] The support and guide assembly is arranged on the inner wall of the graphite tube body 1 , and the bottom surface of the platform 3 is slidably connected to the support and guide assembly. The support and guide assembly is used to support the platform 3 and can guide the platform 3 to slide along the axial direction of the graphite tube body 1 .

[0035] As the number of atomization heating processes increases, the top surface of the platform 3 in contact with the sample 7 will still be heated by the laser beam 9 and aged. At this time, the platform 3 can be pushed to slide along the axial direction of the graphite tube body 1, and the top surface of the platform 3 that has not aged can be moved to the position of the injection hole 2 for continued use. When the top surface of the entire platform 3 is aged, only a new platform 3 needs to be replaced without replacing the graphite tube body 1. Compared with the existing graphite tube, the service life of the graphite tube is greatly extended, and the platform 3 is less difficult to process, saving costs.

[0036] The material of the platform 3 is graphite, tungsten, tantalum, or special ceramics.

[0037] The graphite tube body 1 can be a conventional graphite tube. However, due to the change in the heating method, the platform 3 is actually heated. Therefore, the material of the graphite tube is not limited to graphite, and can also be tungsten, tantalum, special ceramics, etc. The shape of the graphite tube is also not limited, and is preferably cylindrical.

[0038] In some embodiments, as Figure 3 and Figure 4 As shown, the support guide assembly includes two support rails 5, which are located on the bottom inner wall of the graphite tube body 1 and are symmetrically arranged along the axis of the graphite tube body 1. The relative heights of the two support rails 5 are consistent, so that the platform 3 mounted on the support rails 2 and the injection port 2 are parallel to each other.

[0039] In some embodiments, as Figure 5 and Figure 6 As shown, the support guide assembly can also be a plurality of support feet 6 arranged on the inner wall of the graphite tube body 1, and the plurality of support feet 6 are divided into two rows. The two rows of support feet 6 are symmetrically arranged along the axis of the graphite tube body 1, and the relative heights are consistent. Each row of support feet 6 is evenly distributed along the axis of the graphite tube body 1.

[0040] In some embodiments, as Figure 4 and Figure 6 As shown, a groove 4 is also provided on the top surface of the platform 3, and the groove 4 is arranged corresponding to the injection hole 2 to place the sample 7 fed through the injection hole 2. This design helps to maintain the stability of the sample 7 and reduce the movement or dislocation of the sample 7 due to vibration or other external factors.

[0041] Furthermore, a number of cutting grooves are provided on the platform 3 along its length, and adjacent cutting grooves are equidistantly arranged and parallel to each other. The cutting grooves can be selected according to the length of the platform 3. When part of the surface of the platform 3 is aged, the aged part of the platform 3 is broken off and removed by bending (or cutting) the cutting grooves near the aged platform, and the platform 3 that has not aged is retained and moved to the position where the injection hole 2 is located for continued use, thereby further reducing the interference of the aging platform on the detection process.

[0042] Example 2

[0043] In combination with Example 1, the present invention further provides a flameless atomization analysis device, which uses the above-mentioned graphite tube and also includes: a laser irradiator, a temperature meter and a controller.

[0044] The laser irradiator emits a laser beam 9, which passes through the injection hole 2 and enters the graphite tube body 1, irradiating and heating the sample 7 until it is atomized.

[0045] The thermometer is used to directly measure the temperature of the sample 7. The thermometer has a detection element, which is arranged toward the injection hole 2. The exposed portion of the injection hole 2 is aligned with the sample 5 to detect the temperature of the sample 5 in real time. The thermometer can be a common non-contact thermometer. The utility model preferably uses an infrared temperature sensor. The thermometer can emit an indicator light beam 10, such as Figure 7 As shown, the indicator light 10 is mainly used to indicate the measurement direction, and can also be used to indicate the size of the temperature measurement range. The indicator light 10 shown in the figure is only marked to facilitate understanding of the temperature measurement process of the thermometer and does not limit the type of thermometer.

[0046] The size of the injection hole 2 is configured to allow the sample 7 and the laser beam 9 to pass through. The shape of the injection hole 2 is not limited and can be a long strip, etc.

[0047] The laser irradiator and the thermometer are both connected to the controller. The controller can directly control the parameter values ​​of the laser irradiator (such as laser power, pulse width, wavelength, etc.), and can also control the opening and closing and parameter values ​​of the laser beam 9 according to the temperature value detected by the thermometer.

[0048] Furthermore, the flameless atomization analysis device also includes a graphite furnace, a fixing assembly, a light source emitter, and a light absorption detector. The graphite furnace has an inner cavity for accommodating a graphite tube. The graphite tube is detachably connected to the inner wall of the graphite furnace through the fixing assembly. If the graphite tube is damaged or requires regular maintenance, the detachable design allows the operator to easily remove the graphite tube for cleaning or replacement.

[0049] The light source emitter is used to emit a detection light beam 11 of a specific wavelength to illuminate the atomized sample within the graphite tube. The optical path of the detection light beam 11 is located at the central axis of the graphite tube, and the light absorption detector is used to detect the degree of reduction in light intensity after the detection light beam 11 is absorbed by the element to be measured in the sample. Generally speaking, the light source emitter and the light absorption detector are respectively arranged at both ends of the graphite tube body 1. Specifically: the light source emitter is arranged at one end of the graphite tube body 1. The optical path of the emitted detection light beam 11 enters the graphite tube body 1 from one end, passes through the atomization region of the graphite tube 1 (i.e., the region where the sample 5 is atomized) along the central axis of the graphite tube 1, and enters the light absorption detector at the other end of the graphite tube 1. The light absorption detector detects the degree of change in light intensity after the detection light beam 11 is absorbed by the element to be measured in the sample 7.

[0050] It should be noted that the optical path of the laser beam 9 and the optical path of the detection beam 11 need to be staggered.

[0051] Preferably, the fixing assembly includes: a first fixing member and a second fixing member, one end of the graphite tube is detachably connected to the inner wall of the graphite furnace through the first fixing member, and the other end of the graphite tube is detachably connected to the inner wall of the graphite furnace through the second fixing member.

[0052] The first fixing member and the second fixing member mentioned above can be threaded connectors, snap connectors, etc.

[0053] Preferably, the fixing component is a sleeve 8, which is sleeved on the outer wall of the graphite tube, and the outer wall of the sleeve 8 is detachably connected to the inner wall of the graphite furnace.

[0054] The ideal embodiment of the present invention is for inspiration. Through the above description, relevant personnel can make various changes and modifications without departing from the scope of the technical idea of ​​the present invention.

[0055] The technical scope of this utility model is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A graphite tube, characterized in that: include: The hollow graphite tube body, support guide assembly, and platform; The graphite tube body is provided with a sampling hole, and the platform is located in the graphite tube body and is used to carry the sample fed through the sampling hole; The support and guide assembly is arranged on the inner wall of the graphite tube body, the bottom surface of the platform is slidably connected to the support and guide assembly, and the support and guide assembly is used to support the platform and guide the platform to slide along the axial direction of the graphite tube body.

2. The graphite tube according to claim 1, characterized in that The support and guide assembly includes: 2 support rails, The two support rails are symmetrically arranged on the inner wall of the graphite tube body along the axis of the graphite tube body, and have the same relative height.

3. The graphite tube according to claim 1, characterized in that The support and guide assembly includes: a plurality of support feet arranged on the inner wall of the graphite tube body; The plurality of support legs are divided into two rows, and the two rows of support legs are symmetrically arranged along the axis of the graphite tube body and have the same relative height; Each row of the supporting legs is evenly distributed along the axis of the graphite tube body.

4. The graphite tube according to claim 1, characterized in that The top surface of the platform is provided with a groove, the groove is arranged corresponding to the injection hole, and the groove is used to place the sample sent through the injection hole.

5. The graphite tube according to claim 1, characterized in that The platform is made of graphite, tungsten, tantalum, or special ceramics.

6. The graphite tube according to claim 1, characterized in that The graphite tube body is made of graphite, tungsten, tantalum, or special ceramics.

7. The graphite tube according to claim 1, characterized in that The platform is provided with a plurality of cutting grooves along its length direction, and adjacent cutting grooves are arranged at equal distances and parallel to each other.

8. A flameless atomization analysis device, characterized in that: include: The graphite tube, laser irradiator, temperature detector and controller according to any one of claims 1 to 7; The laser irradiator is used to emit a laser beam to irradiate and heat the sample to the atomization temperature; The temperature detector is used to detect the temperature of the sample; The size of the injection hole is suitable for allowing the sample and the laser beam to pass through; The laser irradiator and the temperature detector are both connected to the controller for control. The controller controls the on / off state of the laser irradiator and the laser parameter value according to the temperature value detected by the temperature detector.

9. The flameless atomization analysis device according to claim 8, characterized in that: Also includes: graphite furnace, fixing assembly, light source emitter and light absorption detector, The graphite furnace has an inner cavity for accommodating the graphite tube, and the graphite tube is detachably connected to the inner wall of the graphite furnace through the fixing assembly; The light source emitter is used to emit a detection light beam of a specific wavelength to illuminate the atomized sample in the graphite tube, and the light path of the detection light beam is located at the central axis of the graphite tube; The optical path of the detection beam and the optical path of the laser beam are arranged in an interlaced manner; The light absorption detector is used to detect the degree of change in the light intensity value of the detection light beam after it is absorbed by the element to be detected in the sample.

10. The flameless atomization analysis device according to claim 9, characterized in that: The fixing assembly includes: a first fixing member and a second fixing member, one end of the graphite tube body is detachably connected to the inner wall of the graphite furnace through the first fixing member, and the other end of the graphite tube body is detachably connected to the inner wall of the graphite furnace through the second fixing member; or, The fixing component is a sleeve, which is sleeved on the outer wall of the graphite tube body. The outer wall of the sleeve is detachably connected to the inner wall of the graphite furnace.

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