Atomization heating device and flameless atomization analysis system and method

Abstract

According to the atomization heating device, the flameless atomization analysis system and the flameless atomization analysis method, a direct treatment mode is adopted for heating and temperature control of a sample, the sample is directly irradiated and heated by laser, meanwhile, the temperature of the sample is directly measured, detection conditions can be more intuitively and simply controlled, and higher control precision and test efficiency are provided; the laser heating mode only heats the sample on the premise that the whole graphite pipe is not heated, damage to the graphite pipe is avoided, the service life is prolonged, the contact area of the high-temperature sample and the graphite pipe is reduced, a large number of carbides cannot be generated, and the memory effect and background absorption cannot be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of atomic absorption spectroscopy, and further to an atomization heating device, a flameless atomization analysis system and a method. Background Art

[0002] Atomic absorption spectrometry is a sensitive technique used for elemental analysis. Its detection principle is based on the fact that the elements to be measured in the sample are atomized at high temperatures 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 elements to be measured.

[0003] As one of the atomic absorption spectroscopic analysis techniques, flameless atomic absorption method usually uses electricity to heat graphite tube or high temperature metal boat to make the graphite tube or metal boat generate very high temperature, so that the sample in the graphite tube (or metal boat) is atomized in a very short time. Its advantages include high dispersion efficiency, high sensitivity and strong anti-interference ability, as well as the use of small sample amount. However, the graphite tube is electrified by using a graphite furnace to make it heat up, and the sample placed on its inner surface is heated by the temperature of the graphite tube. At the same time, the temperature of the graphite tube is monitored by a temperature sensor to indirectly infer the temperature of the sample. Such heating and temperature control methods are indirect for sample processing and monitoring. The state of the sample is not completely controllable, and the consistency of the sample can only be guaranteed by sample pretreatment.

[0004] In addition, although the graphite tube itself has been purified, it still contains impurities. After being heated, the impurities will also be atomized. If they happen to be the element to be measured or an interfering substance with similar properties, it will cause deviations in the test results. This deviation is uneven and cannot be accurately quantified and deducted.

[0005] When using a graphite tube to heat the sample for atomic absorption analysis, in addition to the element to be measured, other components or coexisting elements in the sample matrix produce absorption signals (i.e., background absorption). These absorption signals may overlap with the characteristic absorption signals of the element to be measured, resulting in measurement errors, thereby affecting the accuracy of the analysis results.

[0006] On the other hand, although graphite tubes are resistant to high temperatures, they also have a service life, which varies from dozens to hundreds of times depending on the processing technology, the atomization temperature of the element to be measured, and the heating holding time. As the number of uses increases, the surface of the graphite tube will become bumpy, similar to the structure of activated carbon, which may cause the sample to be captured by its structure during atomization to form refractory carbides. After the graphite tube cools, it accumulates on its inner surface. When it accumulates to a certain extent, it will have a visible deviation effect on the test results (i.e., memory effect). The consequence of the memory effect is that the credibility and reproducibility of the measurement results are deteriorated. In addition, aging or damage to the graphite tube may also cause background absorption, because the unevenness or sediment on the surface of the graphite tube may absorb or scatter light, resulting in increased absorbance and background absorption. Summary of the invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide an atomization heating device, a flameless atomization analysis system and a method, which adopt laser direct irradiation to heat the sample, and directly measure the temperature of the sample through a thermometer, and change the heating method and temperature control method of the sample from indirect treatment to direct treatment, which can more intuitively and simply control the detection conditions. The laser irradiation heating method can heat only the sample without heating the entire graphite tube, thereby extending the life of the graphite tube. In addition, the contact area between the high-temperature sample and the low-temperature graphite tube is very small, and a large amount of carbide will not be generated, which is very helpful in reducing the memory effect and background absorption.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] An atomization heating device comprises: a laser irradiator, a temperature meter, a graphite tube and a controller; the graphite tube is provided with a through hole, and a sample enters the graphite tube through the through hole; the laser irradiator is used to emit a laser beam, and the laser beam passes through the through hole to irradiate the sample to heat the sample to an atomized state; the temperature meter is used to detect the temperature of the sample; the laser irradiator and the temperature meter are both connected to the controller for control, and the controller is used to receive the temperature value detected by the temperature meter, and control the opening, closing and parameter value of the laser irradiator according to the temperature value.

[0010] In some embodiments, the through hole is located on the wall of the middle section of the graphite tube, and a size of the through hole is suitable for allowing the sample and the laser beam to pass through.

[0011] In some embodiments, the through hole includes an injection hole and a laser hole, the injection hole is used to allow the sample to enter the graphite tube, and the laser hole is used to allow the laser beam to enter the graphite tube.

[0012] In some embodiments, the through hole further includes a temperature measuring hole, the temperature detector has a detection element, and the detection element is arranged toward the temperature measuring hole to align with the sample and detect the temperature of the sample.

[0013] In some embodiments, the atomization heating device also includes: a light source emitter, which is used to emit a detection beam of a specific wavelength to irradiate the atomized sample, and the optical path of the detection beam is located on the central axis of the graphite tube; the optical path of the laser beam and the optical path of the detection beam are staggered.

[0014] In some embodiments, a platform and a support rail are provided in the graphite tube, the platform is provided with a sample placement groove, and the sample placement groove is arranged corresponding to the injection hole so as to place the sample delivered from the injection hole; a support rail is provided at the lower part of the inner wall of the graphite tube, and two support rails are provided and symmetrically arranged along the central axis of the graphite tube, and the relative heights are consistent; the bottom of the platform is slidably connected to the support rail, and the support rail is used to support and guide the platform.

[0015] The present invention also provides a flameless atomization analysis system, comprising: the above-mentioned atomization heating device, 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; the graphite tube is detachably connected to the inner wall of the graphite furnace through the fixing assembly; an opening corresponding to the through hole is provided on the outer wall of the graphite furnace, so that the sample enters the graphite furnace through the part exposed by the opening and enters the graphite tube from the through hole; the light source emitter is used to emit a detection light beam of a specific wavelength to irradiate the atomized sample; the light absorption detector is used to detect the degree of change in the light intensity value of the detection light beam before and after passing through the atomized sample.

[0016] In some embodiments, 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; the flameless atomization analysis system also includes: a gas supply unit, which is used to transport protective gas to the graphite furnace and the graphite tube to protect the sample and the graphite tube and reduce the interference of interfering components on the detection and analysis; the flameless atomization analysis system also includes: a cooling unit, which is used to supply cooling water to the graphite furnace to adjust the temperature of the graphite furnace; or,

[0017] The fixing component is a sleeve, which is sleeved on the outer wall of the graphite tube, and the outer wall of the sleeve is detachably connected to the inner wall of the graphite furnace; the flameless atomization analysis system also includes: a gas supply unit, which is used to transport protective gas to the graphite furnace and the graphite tube to protect the sample and the graphite tube and reduce the interference of interfering components on detection and analysis; the flameless atomization analysis system also includes: a cooling unit, which is used to supply cooling water to the graphite furnace to adjust the temperature of the graphite furnace.

[0018] The present invention also provides a flameless atomization analysis method, using the above-mentioned atomization heating device or the above-mentioned flameless atomization analysis system, the steps are as follows: S1, sampling and heating process: the graphite tube is fixed in the inner cavity of the graphite furnace, the sample is sent into the graphite tube through the through hole, and the laser irradiator and the thermometer are turned on; the laser irradiator emits a laser beam to irradiate and heat the sample, and the thermometer detects the temperature of the sample in real time; the optical path of the laser beam and the optical path of the detection beam of a specific wavelength are arranged in a staggered manner; the laser irradiator adjusts the parameter value of the laser beam according to the temperature value detected by the thermometer until the laser beam heats the sample to the atomization temperature and forms an atomized gas; S2, detection process: the detection beam irradiates the atomized sample, and by detecting the degree of change in the light intensity value of the detection beam before and after passing through the atomized gas, the content of the element to be measured in the sample is obtained by comparing and calculating with the detection result of the standard sample.

[0019] In some embodiments, before the sample is delivered into the graphite tube through the through hole, the method further includes: turning on a gas supply unit and a cooling unit, wherein the gas supply unit is used to deliver protective gas to the graphite furnace to protect the sample and the graphite tube and reduce interference of interfering components on detection and analysis; the cooling supply unit continuously supplies cooling water to the graphite furnace to adjust the temperature of the graphite furnace when the laser beam heats the sample.

[0020] Compared with the prior art, the atomization heating device, flameless atomization analysis system and method provided by the present invention have the following beneficial effects:

[0021] 1. The atomization heating device provided by the present invention uses a laser irradiator to directly irradiate and heat the sample, and uses a temperature meter to directly measure the temperature of the sample. The heating method and temperature control method of the sample are changed from indirect processing to direct processing. Direct processing can control the detection conditions more intuitively and simply, provide higher control accuracy and test efficiency, and direct processing also reduces the interference of the intermediate links of the detection;

[0022] 2. Compared with the existing technology that uses the overall heating method of the graphite furnace, the present invention uses the laser direct heating method. The laser only heats the sample, not the graphite tube, which prolongs the life of the graphite tube. In addition, the contact area between the high-temperature sample and the graphite tube is small, and a large amount of carbide will not be generated, which reduces the generation of memory effect and improves the accuracy and repeatability of the analysis;

[0023] 3. The present invention uses a method of directly irradiating the sample with laser to reduce the heating range of the graphite tube and extend the life of the graphite tube;

[0024] 4. In the prior art, in order to make the graphite tube reach the corresponding temperature, the power supply of the graphite furnace is usually very large in size and consumes a lot of power. The present invention adopts the method of directly heating the sample by laser, which consumes less energy than heating the entire graphite tube;

[0025] 5. The present application sets a slidable platform in the graphite tube. When the top surface of the platform where the sample is located ages after multiple tests, the platform is moved a certain distance along the axial direction of the graphite tube so that the top surface of the platform that has not aged corresponds to the injection port. The sample can be added again for testing, which greatly reduces the loss of the graphite tube and extends the life of the graphite tube. In addition, the platform is easy to replace, with low processing difficulty and low cost.

[0026] 6. In the flameless atomization analysis system provided in the present application, the laser irradiator and the temperature detector can be integrated into the graphite furnace, which can save 10% to 30% of the instrument volume;

[0027] 7. The flameless atomization analysis method provided by the present invention adopts a specific atomization heating device, uses laser to directly heat the sample and directly measures the temperature. The laser irradiator can change the working state in time according to the actual measured temperature of the thermometer, quickly respond to changes in test conditions, adapt to different detection requirements, improve detection efficiency, and provide more consistent operating conditions, which is conducive to the repeatability of experimental results and ensures the scientificity and effectiveness of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The preferred implementation modes will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0029] Figure 1 A schematic diagram of the structure of the atomization heating device provided in Example 1 of the present invention;

[0030] Figure 2 An axial cross-sectional view of the atomization heating device provided in Example 1 of the present invention;

[0031] Figure 3 A radial cross-sectional view of the atomization heating device provided in Example 1 of the present invention;

[0032] Figure 4 A schematic diagram of the structure of the platform provided by the present invention;

[0033] Figure 5 A schematic diagram of the structure of the support rail provided by the present invention;

[0034] Figure 6 An axial cross-sectional view of an atomization heating device according to another embodiment of the present invention provided in Example 1;

[0035] Figure 7 A schematic diagram of the structure of an atomization heating device provided in Example 2 of the present invention;

[0036] Figure 8 An axial cross-sectional view of an atomization heating device provided in Example 2 of the present invention;

[0037] Fig. 9 An axial cross-sectional view of an atomization heating device according to another embodiment of the present invention provided in Example 2;

[0038] Fig.10 A top view of a graphite tube according to another embodiment of the present invention provided in Example 2;

[0039] Fig.11 A schematic structural diagram of an atomization heating device according to another embodiment of the present invention;

[0040] Fig.12 A schematic structural diagram of an atomization heating device according to another embodiment of the present invention;

[0041] Fig.13 This is a schematic structural diagram of the flameless atomization analysis system provided by the present invention.

[0042] Description of Figure Numbers:

[0043] 1—graphite tube; 11—injection hole; 12—laser hole; 13—temperature measurement hole; 14—platform; 15—sample groove; 16—support rail; 17—sleeve;

[0044] 2—laser irradiator; 20—laser beam;

[0045] 3—temperature detector; 30—indicator beam;

[0046] 4—light source transmitter; 40—detection beam;

[0047] 5—Sample. DETAILED DESCRIPTION

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0049] In order to simplify the drawings, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0050] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0051] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In addition, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0053] Example 1

[0054] The present invention provides an atomization heating device, such as Figure 1-6 As shown, it includes a laser irradiator 2, a temperature meter 3, a graphite tube 1 and a controller, wherein the graphite tube 1 is provided with a through hole, and the sample 5 enters the graphite tube through the through hole.

[0055] The laser irradiator 2 emits a laser beam 20 , which passes through the through hole into the graphite tube to irradiate the sample, thereby heating the sample 5 to an atomic state.

[0056] The temperature measuring device 3 has a detection element, which is arranged toward the through hole and is aligned with the sample 5 through the exposed portion of the through hole to detect the temperature of the sample 5 in real time.

[0057] The thermometer 3 can be a common non-contact thermometer. The present invention preferably uses an infrared temperature sensor. The detection element of the infrared temperature sensor collects the infrared radiation energy emitted by the sample 5 and then converts the collected energy into a temperature value. The thermometer 3 can emit an indication light beam 30, such as Figure 1 As shown, the indicator light beam 30 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 beam 30 shown in the figure is only marked to facilitate understanding of the temperature measurement process of the thermometer 3, and does not limit the type of the thermometer 3.

[0058] The laser irradiator 2 and the thermometer 3 are both connected to the controller, which is used to control the opening and closing of the laser irradiator and the parameter value (such as laser power, pulse width, wavelength, etc.). The controller can also control the opening and closing and parameter value of the laser beam 20 according to the temperature information detected by the thermometer 3.

[0059] Specific:

[0060] Combination Figure 1 - Figure 3 As shown, the through hole is located on the tube wall of the middle section of the graphite tube 1. The size of the through hole 11 is configured to allow the sample 5 and the laser beam 20 to pass through and enter the graphite tube 1. The shape of the through hole is not limited. In actual use, the shape of the through hole can be set to a long strip.

[0061] After the sample 5 is sucked by the injector and inserted into the graphite tube 1 through the through hole, the sample 5 is released on the inner wall at the bottom of the graphite tube 1 , and the injector is then removed from the graphite tube 1 through the through hole.

[0062] The laser 2 and the thermometer 3 are turned on, and the laser beam 20 passes through the through hole into the graphite tube 1 to irradiate and heat the sample 5. The thermometer 3 is aimed at the sample through the exposed part of the through hole to detect the temperature of the sample 5. After several heating stages of drying, ashing, and atomization, impurities are driven away and the sample 5 is atomized.

[0063] After the sample 5 is heated to atomization by the laser beam 20, a detection beam 40 of a specific wavelength is emitted by a light source emitter (usually a hollow cathode lamp of the element to be measured) to irradiate the atomized sample 5. The detection beam 40 corresponds to the resonant absorption line of the element to be measured in the sample 5. The optical path of the detection beam 40 passes through the atomization area in the graphite tube 1. The optical path of the detection beam 40 is usually located on the central axis of the graphite tube 1. At this time, the laser 2 and the thermometer 3 are still in working state. Therefore, in the initial stage of heating of the sample 5, the optical path of the laser beam 20 and the optical path of the detection beam 40 should be staggered.

[0064] The ground state atoms of the element to be measured in the sample 5 will absorb the detection light beam 40 of a specific wavelength that resonates with them. The detection light beam 40 passes through the atomization area of ​​the sample in the graphite tube 1 and enters the light absorption detector. The light absorption detector measures the degree of change in the light intensity value of the detection light beam 40 before and after passing through the atomization area, and compares and calculates it with the detection result of the standard sample to finally obtain the content of the element to be measured in the sample 5.

[0065] The present invention adopts a heating method of direct irradiation by a laser irradiator 2, and uses a thermometer 3 to directly measure the sample temperature. Compared with the existing indirect processing, this direct heating and temperature control method can control the detection conditions more intuitively and simply. Direct heating can also make the sample reach the required temperature more quickly, thereby shortening the heating time and improving the efficiency of the entire detection process.

[0066] During the use of traditional graphite furnaces, since the graphite tube is at high temperature as a whole, the memory effect is particularly serious for some elements that can form refractory carbides, which affects the determination of subsequent samples. The present invention adopts a laser irradiation heating method, and the laser only heats the sample 5. The contact area between the high-temperature sample and the low-temperature graphite is small, and a large amount of carbides will not be generated, which is very helpful in reducing the memory effect.

[0067] On the other hand, the existing overall heating method of the graphite tube causes serious degradation of the graphite tube and shortens its service life. The present invention changes the heating position of the graphite tube 1 from the entire graphite tube to heating only within the irradiation range of the laser beam 20, thereby extending the service life of the graphite tube 1.

[0068] In some embodiments, in order to further reduce the loss of the graphite tube 1 , the present invention provides a slidable platform 14 inside the graphite tube 1 .

[0069] like Figure 4-6 As shown, a support rail 16 is provided at the lower part of the inner wall of the graphite tube 1 , and two support rails 16 are provided and are arranged along the central axis of the graphite tube 1 , and the relative heights are consistent.

[0070] The bottom of the platform 14 is slidably connected to the support rail 16, and the support rail 16 supports and guides the platform 14, that is, the platform 14 can move along the axial direction of the graphite tube 1, and the top surface of the platform 14 can be placed on the sample 5 fed from the through hole. The part of the top surface of the platform 14 where the sample 5 is placed (which is also the top surface of the platform 14 corresponding to the through hole) ages after multiple laser irradiations. The platform 14 can be moved a certain distance along the axial direction of the graphite tube 1, and the unaged top surface of the platform 14 can be moved to a position relative to the through hole for continued use. When the entire top surface of the platform 14 is aged, a new platform 14 can be directly replaced without replacing a new graphite tube 1. In addition, compared with the graphite tube 1, the platform 14 is less difficult to process and has a lower cost. Compared with the overall heating method of the graphite tube 1, the slidable platform 14 reduces the loss of the graphite tube 1 and extends its service life.

[0071] Furthermore, a sample placement groove 15 is provided on the top surface of the platform 14 , and the sample placement groove 15 is arranged corresponding to the through hole 11 so as to place the sample 5 sent from the through hole.

[0072] Furthermore, the material of the platform 14 can be graphite, or metal tungsten, or tantalum, or special ceramics (zirconium diboride), etc.

[0073] Example 2

[0074] On the basis of Example 1, Figure 7 - Fig. 9 As shown, the through hole includes an injection hole 11 and a laser hole 12. The sample enters the graphite tube 1 through the injection hole 11. The laser beam 20 passes through the laser hole 12 and extends into the graphite tube 1 to irradiate and heat the sample 5. The optical path of the laser beam 20 and the optical path of the detection beam 40 are staggered. The thermometer 13 can measure the temperature of the sample 5 through the injection hole 11.

[0075] In some embodiments, a separate temperature measuring hole 13 may be further provided on the wall of the graphite tube 1, and the detection element of the thermometer 3 is arranged toward the temperature measuring hole 13, and is aimed at the sample 5 to directly detect the temperature of the sample 5. The laser beam 20 may irradiate the sample through a separate laser hole 12, or may irradiate the sample through the injection hole 11.

[0076] Furthermore, the locations of the laser hole 12 and the temperature measuring hole 13 are not limited and can be as follows: Figure 7-9 As shown, it is on the same axis as the injection hole 11.

[0077] In some embodiments, the laser hole 12 and the temperature measuring hole 13 may not be on the same axis as the injection hole 11. Fig.10 As shown, the injection hole 11, the laser hole 12 and the temperature measuring hole 13 are all arranged on the top of the graphite tube 1, but the three holes are staggered.

[0078] In addition, when a laser hole 12 or a temperature measuring hole 13 is provided separately, the laser hole 12 or the temperature measuring hole 13 may be on the same axis as the injection hole 11 , or may not be on the same axis as the injection hole 11 .

[0079] In some embodiments, the laser hole 12 and the temperature measuring hole 13 can also be arranged at different positions on the wall of the graphite tube 1 from the injection hole 11, such as Fig.11 As shown, the laser hole 12 and the temperature measuring hole 13 are arranged at the top of the graphite tube 1 and are located on the same axis. For ease of understanding, the wall of the graphite tube 1 is divided into a symmetrical left wall and a right wall along the radial direction of the graphite tube 1, and the temperature measuring hole 13 is arranged on the left wall (it can also be arranged on the right wall). Fig.12As shown, the laser hole 12 and the temperature measuring hole 13 are both arranged on the left side wall, and the laser hole 12 and the temperature measuring hole 13 can also be staggered.

[0080] Further, such as Fig. 9 As shown, the slidable platform 14 in Example 1 can be arranged in the graphite tube 1, and the sample placement groove 15 is arranged corresponding to the injection hole 11. The specific structure and function of the platform 14 are not repeated here.

[0081] Example 3

[0082] On the basis of Example 1 and Example 2, the present invention further provides a flameless atomization analysis system, which uses the above-mentioned atomization heating device and also includes: a graphite furnace, a fixing component, a light source emitter and a light absorption detector.

[0083] The graphite furnace has an inner cavity for accommodating the above-mentioned graphite tube 1. The graphite tube 1 is detachably connected to the inner wall of the graphite furnace through a fixing component. The fixing component fixes the graphite tube 1 in the graphite furnace to prevent the graphite tube 1 from being displaced or damaged during high-temperature heating, thereby ensuring the quality and efficiency of atomic absorption spectrometry analysis.

[0084] An opening corresponding to the injection hole 11 is provided on the outer wall of the graphite furnace, so that the sample 5 can enter the graphite furnace through the exposed portion of the opening and enter the graphite tube 1 from the injection hole 11 .

[0085] When the graphite tube 1 is further provided with a laser hole 12 and a temperature measuring hole 13 , two openings corresponding to the laser hole 12 and the temperature measuring hole 13 are respectively provided on the graphite furnace so that the laser beam 20 and the indicator beam 30 irradiate the sample 5 .

[0086] Preferably, the finished laser irradiator with power supply currently available on the market is only the size of a power bank, and the laser irradiator 2 can be integrated into the graphite furnace to reduce the size of the instrument. Similarly, the temperature sensor 3 can also be integrated into the graphite furnace.

[0087] The light source emitter is used to emit a detection light beam 40 of a specific wavelength to irradiate the atomized sample. The light source emitter is arranged at one end of the graphite tube 1, and a light absorption detector is arranged at the other end of the graphite tube 1. The light path of the emitted detection light beam 40 enters the graphite tube 1 from one end of the graphite tube 1, and passes through the atomization area of ​​the graphite tube 1 (i.e., the area where the sample 5 is atomized) along the central axis of the graphite tube 1 to enter the light absorption detector at the other end of the graphite tube 1. The light absorption detector detects the degree of change in the light intensity value of the detection light beam 40 before and after passing through the atomization area.

[0088] In some embodiments, the fixing assembly includes a first fixing member and a second fixing member, one end of the graphite tube 1 is detachably connected to the inner wall of the graphite furnace through the first fixing member, and the other end of the graphite tube 1 is detachably connected to the inner wall of the graphite furnace through the second fixing member.

[0089] The first fixing member and the second fixing member mentioned above can be threaded connectors, snap connectors, etc.

[0090] In some embodiments, Fig.13 As shown, the fixing component is a sleeve 17, which is sleeved on the outer wall of the graphite tube 1, and the outer wall of the sleeve 17 is detachably connected to the inner wall of the graphite furnace.

[0091] Furthermore, the sleeve 17 is a two-section structure, the two sections of the sleeve 17 are respectively sleeved on the two ends of the graphite tube 1 , and the through hole 11 is located on the tube wall of the graphite tube 1 between the two sections of the sleeve 17 .

[0092] In some embodiments, the flameless atomization analysis system further includes: a gas supply unit for delivering protective gas to the graphite furnace and the graphite tube 1 .

[0093] Furthermore, the protective gases are external gas and internal gas (also called carrier gas). The external gas flows outside the wall of the graphite tube 1 to form a protective layer, which protects the surface of the graphite tube 1 from being oxidized by contact with oxygen during heating and high-temperature atomization, avoids damage to the graphite tube 1, and protects the sample in the graphite tube from chemical reaction with the atmosphere during drying, ashing, and atomization, thereby ensuring the accuracy of detection and analysis.

[0094] The internal gas enters from the optical path direction of the graphite tube 1 (the two ends of the graphite tube 1) and flows out from the injection hole 11 at the center of the tube. The internal gas will carry out the matrix interfering components such as the sample solvent and the vapor of the coexisting substances heated and evaporated in the drying and ashing stage from the injection hole 11 to avoid interference with the analysis results. However, the internal gas is closed in the atomization stage of the heating program to prevent the internal gas from carrying away the sample to be tested.

[0095] Both the outer gas and the inner gas can be argon (Ar), helium (He) or nitrogen (N2), preferably argon.

[0096] In some embodiments, the flameless atomization analysis system further includes: a cooling unit for supplying cooling water to the graphite furnace, wherein the cooling water flows along the outer wall of the graphite furnace to adjust the internal temperature of the graphite furnace and protect the graphite furnace from overheating.

[0097] Example 4

[0098] The present invention also provides a flameless atomization analysis method, using the flameless atomization analysis system in Example 3, the steps include:

[0099] S1, injection and heating process:

[0100] The graphite tube 1 is fixed in the inner cavity of the graphite furnace, the sample 5 is fed into the graphite tube through the injection hole 11, and the laser irradiator 2 and the temperature meter 3 are turned on.

[0101] When the graphite tube 1 provided in Example 1 is used, the laser irradiator 2 emits a laser beam 2 through the injection hole 11 to irradiate the sample 5, the laser beam 2 heats the sample 5, and the indicator beam 3 is aimed at the sample 5 to detect the temperature of the sample 5; when the graphite tube 1 provided in Example 2 is used, the laser irradiator 2 emits a laser beam 2 through the laser hole 12 to irradiate the sample 5, and the temperature meter 3 emits an indicator beam 30 through the temperature measuring hole 3 to irradiate the sample 5.

[0102] The optical path of the laser beam 20 is interlaced with the optical path of the detection beam 40 emitted by the light source emitter, and the optical path of the indicator beam 30 is interlaced with the optical path of the detection beam 40 .

[0103] The parameter value of the laser beam 20 is adjusted according to the temperature value detected by the thermometer 3. After several heating stages including drying, ashing, atomization and cleaning, the laser beam 20 continuously heats the sample 5, drives away impurities and heats the sample 5 to form an atomized gas. After the detection is completed, the sample is heated to a temperature higher than the atomization temperature of the sample to clean the sample residue.

[0104] S2. Detection process:

[0105] After the sample 5 is atomized, the light source emitter is turned on to emit a detection light beam 40 of a specific wavelength to irradiate the atomized sample 5 . The ground state atoms of the element to be detected in the sample 5 will absorb the characteristic radiation of the element to be detected in the detection light beam 40 .

[0106] After the detection light beam 40 passes through the area where the atomized sample (atomized gas) is located, it enters the light absorption detector to detect the degree of change in the light intensity value of the detection light beam 40 before and after passing through the atomized gas. After comparing and calculating with the detection results of the standard sample, the content of the element to be measured in the sample 5 is obtained.

[0107] In some embodiments, in step S1, before the sample 5 is fed into the graphite tube 1 through the injection hole 11, the step also includes: turning on the gas supply unit and the cooling unit, wherein the gas supply unit is used to deliver protective gas to the inner cavity of the graphite furnace to protect the sample 5 and the graphite tube 1, and to reduce the interference of interfering components on the detection and analysis.

[0108] At the same time, the cooling supply unit supplies cooling water to continuously flow on the outer wall of the graphite furnace to adjust the internal temperature of the graphite furnace when the laser beam 20 heats the sample 5 to prevent the graphite furnace from being damaged due to high temperature.

[0109] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An atomization heating device, It is characterized in that include: Laser irradiator, temperature detector, graphite tube and controller; The graphite tube is provided with a through hole, and the sample enters the graphite tube through the through hole; The laser irradiator is used to emit a laser beam, and the laser beam passes through the through hole to irradiate the sample to heat the sample to an atomic state; The temperature detector is used to detect the temperature of the sample; The laser irradiator and the temperature detector are both connected to the controller for control. The controller is used to receive the temperature value detected by the temperature detector and control the opening, closing and parameter value of the laser irradiator according to the temperature value.

2. The atomization heating device according to claim 1, It is characterized in that The through hole is located on the tube wall of the middle section of the graphite tube, and the size of the through hole is suitable for allowing the sample and the laser beam to pass through.

3. The atomization heating device according to claim 1, It is characterized in that The through hole comprises a sample injection hole and a laser hole. The sample injection hole is used for allowing the sample to enter the graphite tube, and the laser hole is used for allowing the laser beam to enter the graphite tube.

4. The atomization heating device according to any one of claims 1 to 3, It is characterized in that The through hole also includes a temperature measuring hole, The temperature detector has a detection element, and the detection element is arranged toward the temperature measuring hole to align with the sample and detect the temperature of the sample.

5. The atomization heating device according to claim 1, It is characterized in that It also includes: a light source emitter, the light source emitter is used to emit a detection light beam of a specific wavelength to irradiate the atomized sample, and the light path of the detection light beam is located at the central axis of the graphite tube; The optical path of the laser beam and the optical path of the detection beam are arranged in a staggered manner.

6. The atomization heating device according to claim 3, It is characterized in that A platform and a support rail are provided in the graphite tube, a sample placement groove is provided on the platform, and the sample placement groove is arranged corresponding to the injection hole so as to place the sample sent from the injection hole; A support rail is provided at the lower part of the inner wall of the graphite tube, and two support rails are provided and are symmetrically arranged along the central axis of the graphite tube, and have the same relative height; The bottom of the platform is slidably connected to the support rail, and the support rail is used to support and guide the platform.

7. A flameless atomization analysis system, It is characterized in that include: The atomization heating device, graphite furnace, fixing assembly, light source emitter and light absorption detector according to any one of claims 1 to 6, The graphite furnace has an inner cavity for accommodating the graphite tube; The graphite tube is detachably connected to the inner wall of the graphite furnace through the fixing assembly; An opening corresponding to the through hole is provided on the outer wall of the graphite furnace, so that the sample enters the graphite furnace through the exposed portion of the opening and enters the graphite tube from the through hole; The light source emitter is used to emit a detection light beam of a specific wavelength to irradiate the atomized sample; The light absorption detector is used to detect the degree of change in the light intensity value of the detection light beam before and after passing through the atomized sample.

8. The flameless atomization analysis system according to claim 7, It is characterized in that The fixing assembly comprises: 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; The flameless atomization analysis system further includes: a gas supply unit, which is used to deliver protective gas to the graphite furnace and the graphite tube to protect the sample and the graphite tube and reduce the interference of interfering components on the detection and analysis; The flameless atomization analysis system further includes: a cooling unit for supplying cooling water to the graphite furnace to adjust the temperature of the graphite furnace; or, The fixing component is a sleeve, which is sleeved on the outer wall of the graphite tube, and the outer wall of the sleeve is detachably connected to the inner wall of the graphite furnace; The flameless atomization analysis system further includes: a gas supply unit, which is used to deliver protective gas to the graphite furnace and the graphite tube to protect the sample and the graphite tube and reduce the interference of interfering components on the detection and analysis; The flameless atomization analysis system further includes a cooling unit for supplying cooling water to the graphite furnace to adjust the temperature of the graphite furnace.

9. A flameless atomization analysis method, It is characterized in that Using the flameless atomization analysis system according to any one of claims 7 to 8, the steps are as follows: S1, injection and heating process: The graphite tube is fixed in the inner cavity of the graphite furnace, the sample is sent into the graphite tube through the through hole, and the laser irradiator and the temperature meter are turned on; The laser irradiator emits a laser beam to irradiate and heat the sample, and the temperature detector detects the temperature of the sample in real time; The optical path of the laser beam and the optical path of the detection beam of a specific wavelength are arranged in a staggered manner; The laser irradiator adjusts the parameter value of the laser beam according to the temperature value detected by the temperature detector until the laser beam heats the sample to the atomization temperature and forms an atomized gas; S2. Detection process: The detection light beam irradiates the atomized sample, and by detecting the degree of change in the light intensity of the detection light beam before and after passing through the atomized gas, the content of the element to be measured in the sample is obtained by comparing and calculating with the detection result of the standard sample.

10. The flameless atomization analysis method according to claim 9, It is characterized in that Before the sample is fed into the graphite tube through the through hole, the method further comprises: Turning on a gas supply unit and a cooling unit, wherein the gas supply unit is used to deliver protective gas to the graphite furnace to protect the sample and the graphite tube and reduce interference of interfering components on detection and analysis; The cooling supply unit continuously supplies cooling water to the graphite furnace to adjust a temperature of the graphite furnace when the laser beam heats the sample.

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