Atomic absorption double-optical-path device based on optical fiber light splitting

Abstract

The atomic absorption double-light-path device comprises a light source, a monochromator and a light splitting device, the light splitting device achieves light path separation and modulation through an efficient light pick-up head, a light splitting optical fiber, a condensing lens, a light chopper and a converging optical fiber, light of the light source is divided into a sample light path and a reference light path, and the sample light path and the reference light path are transmitted into the monochromator; meanwhile, the sample light path sensitivity is improved through the atomizer. The optical path stability and the detection precision are improved, background light interference is effectively eliminated, multi-optical-path time sequence adjustment is realized, and the accuracy and the reliability of atomic absorption analysis are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of atomic absorption spectroscopy detection technology, and in particular to an atomic absorption dual-path device based on fiber optic spectroscopy. Background Technology

[0002] Atomic absorption spectroscopy (AAS), as an important analytical technique, has wide applications in environmental monitoring, food testing, and pharmaceutical research and development. By accurately measuring the absorption of light at specific wavelengths by a sample, highly sensitive detection of trace metal elements in the sample can be achieved. The development of this technology has greatly promoted the progress of modern analytical chemistry, providing a powerful tool for scientific research and industrial production. With the increasing demands for detection, further improving the accuracy and stability of detection, and reducing background interference and noise, has become an important research direction. In existing technologies, the following methods are commonly used to improve the accuracy of atomic absorption spectroscopy detection: first, optimizing the design of optical elements to reduce interference caused by light source fluctuations and surface reflections of optical elements; second, using filters or interference filters to initially subtract background signals; and third, improving the atomizer structure to optimize the interaction conditions between the sample and the light beam. In addition, a common method is to use a dual-path design, dividing the light source into a reference path and a sample path, and subtracting background interference by comparing the differences between the two signals. These methods improve detection performance to some extent, but still have certain limitations. However, existing dual-optical-path designs often suffer from problems such as complex optical path layout, significant energy loss, and physical separation between the reference optical path and the sample optical path, resulting in incomplete substrate interference subtraction and difficulty in further improving detection stability. Utility Model Content

[0003] To overcome the above problems, this application provides an atomic absorption dual-path device based on optical fiber spectral splitting.

[0004] The atomic absorption dual-path device based on fiber optic beam splitting provided in this application adopts the following technical solution:

[0005] An atomic absorption dual-path device based on fiber optic beam splitting, comprising:

[0006] light source;

[0007] Monochromator;

[0008] A beam splitter, which splits the light from the light source into a sample light path and a reference light path and transmits it to the monochromator, includes a high-efficiency pickup head, a beam splitting fiber, a condensing lens, a first chopper, a second chopper, an atomizer, and a converging fiber. The high-efficiency pickup head includes a pickup and focusing end and a light output end, which is located at the light output port of the light source. One end of the beam splitter is connected to the light output end, and the other end is connected to the first chopper. The first chopper eliminates background light and splits the beam into reference light and sample light. The rear side of the chopper is connected to the condensing lens, which modulates the beam into parallel light. The second chopper is located behind the condensing lens and periodically loads the light source. The atomizer is located inside the condensing lens where the sample light path is located to improve the sensitivity of the sample light path. The converging fiber is connected to the second chopper where the sample light path and the reference light path are located, respectively, and transmits the light source to the monochromator.

[0009] By adopting the above technical solutions, the high-efficiency light-collecting head reduces light energy loss and ensures stable transmission of optical signals through the design of the light-collecting and focusing ends and the light-emitting ends; the beam-splitting fiber achieves optical path separation and avoids cross-interference; the first chopper eliminates background light and significantly improves detection accuracy; the focusing lens modulates the beam into parallel light and optimizes the optical path transmission quality; the second chopper periodically loads the light source to achieve optical path timing control; the atomizer is set in the focusing lens where the sample optical path is located, further improving the sensitivity of the sample optical path; and the converging fiber accurately transmits the optical signals of the sample optical path and the reference optical path to the monochromator, ensuring the reliability of the detection results.

[0010] Preferably, the light source includes an element light box and a deuterium lamp.

[0011] By adopting the above technical solution, the element light box and deuterium lamp serve as light sources, providing stable excitation and background light sources. The light emitted from the element light box is used for sample detection, while the light emitted from the deuterium lamp is used for background subtraction, thereby effectively improving the accuracy and reliability of the detection.

[0012] Preferably, the optical splitter includes a first optical splitter connected to the element light box and a second optical splitter connected to the deuterium lamp. The first optical splitter is used to transmit light emitted from the element light box, and the second optical splitter is used to transmit light emitted from the deuterium lamp.

[0013] By adopting the above technical solution, the first and second optical fibers are used to transmit the light emitted by the element light box and the deuterium lamp, respectively, achieving independent transmission of the two light sources and avoiding interference between optical paths. This design can effectively reduce the influence of background signals, improve detection stability, and reduce noise and drift, thereby improving the background subtraction effect.

[0014] Preferably, the first chopper divides the optical path into an element lamp sample optical path, an element lamp reference optical path, a deuterium lamp sample optical path, and a deuterium lamp reference optical path.

[0015] By adopting the above technical solution, the first chopper divides the optical path into an element lamp sample optical path, an element lamp reference optical path, a deuterium lamp sample optical path, and a deuterium lamp reference optical path, thereby achieving the separation and distribution of beams from different light sources. The setting of the first chopper allows the sample optical path and the reference optical path to process the beams of the element lamp and the deuterium lamp respectively, further improving the flexibility of the optical path design and the accuracy of substrate interference subtraction.

[0016] Preferably, the second chopper sequentially adjusts the light timing entering the monochromator to: element lamp sample light path, deuterium lamp reference light path, element lamp reference light path, and deuterium lamp sample light path.

[0017] By employing the above technical solution, the second chopper periodically loads the optical path and sequentially adjusts the timing of the light entering the monochromator to the element lamp sample optical path, the deuterium lamp reference optical path, the element lamp reference optical path, and the deuterium lamp sample optical path, thereby achieving precise control and switching of different optical paths. This maximizes the reduction of substrate interference, improving the sensitivity and accuracy of atomic absorption detection.

[0018] Preferably, the diameter of the light-collecting and focusing end is larger than the diameter of the light-emitting end.

[0019] By adopting the above technical solution, the design of having a larger diameter at the light-collecting end than at the light-emitting end can effectively expand the range of light sources, improve light collection efficiency, and reduce light energy loss, thereby enhancing the stability and sensitivity of the entire optical path system.

[0020] Preferably, a mirror coating is provided on the inner side of the conduit between the light-collecting and light-emitting end and the light-emitting end.

[0021] By adopting the above technical solution, the mirror coating on the inner side of the tube between the light-collecting and light-emitting ends can effectively reduce energy loss during light transmission and improve light utilization. The mirror coating can enhance the light signal intensity, reduce background noise, and improve detection sensitivity and stability, thereby achieving more accurate background subtraction and sample analysis.

[0022] Preferably, the atomizer is a flame head.

[0023] By employing the above technical solution, the flame head, acting as an atomizer, can effectively realize the interaction between sample light and the sample to be tested. The high-temperature environment provided by the flame head allows the sample to be fully atomized, thereby enhancing the absorption effect between sample light and sample elements, and improving detection sensitivity and accuracy.

[0024] Preferably, the monochromator includes a slit and optical elements.

[0025] By adopting the above technical solution, the monochromator in the fiber-optic splitting atomic absorption dual-path device, comprising a slit and optical elements, can precisely split the incoming light, thereby improving the detection resolution and sensitivity. Specifically, the slit design helps to filter light signals within a specific wavelength range, reducing the influence of stray light; the optical elements further achieve effective spectral separation, ensuring the accuracy of the detection results.

[0026] Preferably, it also includes a driver that adjusts the position of the high-efficiency light-collecting head to align the light-collecting and focusing end with the light-emitting port of the light source.

[0027] By adopting the above technical solution, the driver can precisely adjust the position of the high-efficiency light-collecting head, ensuring accurate alignment between the light-collecting and focusing end and the light-emitting port of the light source. This effectively improves light collection efficiency, reduces light energy loss, and thus enhances the detection sensitivity and stability of the entire device.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. By combining optical fibers and optical lenses, dual-optical-path transmission is achieved. The energy loss at the front end of the optical path is small and stable, which significantly improves the detection stability while reducing noise and drift.

[0030] 2. The reference optical path can be flexibly arranged close to the sample optical path to minimize substrate interference, optimize the instrument's spatial layout, and improve the effect of background signal subtraction;

[0031] 3. The synergistic effect of the first and second choppers enables precise control of the optical path, effectively separating and sequentially loading the reference light and sample light, further enhancing detection accuracy and sensitivity. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of an atomic absorption dual-path device based on optical fiber spectroscopy, as described in this application.

[0033] Figure 2 This is a schematic diagram of a high-efficiency optical pickup head structure.

[0034] Explanation of reference numerals in the attached diagram: 1. Light source; 11. Element light box; 12. Deuterium lamp; 2. Monochromator; 3. Beam splitter; 31. High-efficiency light pickup head; 311. Light pickup and focusing end; 312. Light output end; 313. Driver; 32. Beam splitting fiber; 321. First beam splitting fiber; 322. Second beam splitting fiber; 33. Condensing lens; 34. First chopper; 35. Second chopper; 36. Atomizer; 37. Converging fiber. Detailed Implementation

[0035] The following is in conjunction with the appendix Figure 1-2 This application will be described in further detail.

[0036] This application discloses an atomic absorption dual-path device based on fiber optic beam splitting. (Refer to...) Figure 1 The atomic absorption dual-path device based on fiber optic spectroscopy includes a light source 1, a monochromator 2, and a spectral splitter 3. The spectral splitter 3 splits the light from the light source 1 into a sample light path and a reference light path, and transmits them to the monochromator 2.

[0037] Specifically, the light source 1 includes an element light box 11 and a deuterium lamp 12. The optical fiber 32 includes a first optical fiber 321 connected to the element light box 11 and a second optical fiber 322 connected to the deuterium lamp 12. The first optical fiber 321 is used to transmit the light emitted by the element light box 11, and the second optical fiber 322 is used to transmit the light emitted by the deuterium lamp 12. By introducing the deuterium lamp 12 as the background correction light source 1, the effect of background signal subtraction is further improved, and the problem of chemical background interference is solved.

[0038] The beam splitting device 3 specifically includes a high-efficiency pickup head 31, a beam splitting fiber 32, a focusing lens 33, a first chopper 34, a second chopper 35, an atomizer 36, and a converging fiber 37.

[0039] The high-efficiency light-collecting head 31 includes a light-collecting and focusing end 311 and a light-emitting end 312. The light-collecting and focusing end 311 is located at the light-emitting port of the light source 1 and is aligned with the light-emitting port of the light source 1 by a driver 313, thereby improving the light collection efficiency. The driver 313 can be a stepper motor or a servo motor, which optimizes the optical path by precisely controlling the position of the high-efficiency light-collecting head 31.

[0040] Reference Figure 2 Specifically, the high-efficiency light-collecting head 31 adopts a conical structure. The light-collecting and focusing end 311 is used to collect the light emitted by the light source 1, and its diameter is larger than that of the light-emitting end 312 to improve the light collection efficiency. The light-emitting end 312 transmits the collected light to the beam-splitting fiber 32, which has a smaller diameter to facilitate beam focusing. The inner side of the tube of the high-efficiency light-collecting head 31 is provided with a mirror coating, such as a silver-plated or aluminum-plated coating, to further reduce light scattering and absorption.

[0041] Reference Figure 1 One end of the beam splitter 32 is connected to the light output end 312, and the other end is connected to the first chopper 34. The first chopper 34 eliminates the background light and splits the beam into reference light and sample light.

[0042] The optical fiber 32 includes a first optical fiber 321 connected to the element light box 11 and a second optical fiber 322 connected to the deuterium lamp 12. The first optical fiber 321 is used to transmit the light emitted by the element light box 11, and the second optical fiber 322 is used to transmit the light emitted by the deuterium lamp 12. The optical fiber 32 can be made of multimode fiber or single-mode fiber, and is covered with a protective layer to prevent damage to the fiber from the external environment.

[0043] The first chopper 34 is connected to the condenser lens 33 at its rear end, and modulates the light beam into parallel light through the condenser lens 33. A second chopper 35 is disposed at the rear end of the condenser lens 33, and the second chopper 35 periodically loads the light source 1. The atomizer 36 is disposed inside the condenser lens 33 where the sample light path is located, to improve the sensitivity of the sample light path. The converging fiber 37 is connected to the second chopper 35 where the sample light path and the reference light path are located, respectively, and transmits the light source 1 to the monochromator 2.

[0044] Specifically, the first chopper 34 divides the optical path into an element lamp sample optical path, an element lamp reference optical path, a deuterium lamp 12 sample optical path, and a deuterium lamp 12 reference optical path. The first chopper 34 can be a rotary chopper or an electromagnetic chopper, and the optical path is switched by periodically blocking the beam. The switching frequency of the first chopper 34 can be adjusted according to actual needs to ensure the accuracy and stability of the optical path switching.

[0045] The second chopper 35 sequentially adjusts the timing of the light entering the monochromator 2 as follows: the sample light path of the element lamp, the reference light path of the deuterium lamp 12, the reference light path of the element lamp, and the sample light path of the deuterium lamp 12. The second chopper 35 can adopt the same or different structural form as the first chopper 34. Its main function is to periodically load the light source 1 to achieve timing control of the light path.

[0046] The atomizer 36 is located within the condenser lens 33 in the sample optical path and is used to convert the analyte in the sample into an atomic state. The atomizer 36 can be a flame head or other types of atomizers, such as a graphite furnace atomizer or a hydride generator. The flame head structure includes a combustion chamber and a nozzle. Fuel gas and combustion-supporting gas are introduced into the combustion chamber, and the nozzle is used to spray the sample solution. The working principle of the flame head is to convert the analyte in the sample into an atomic state through a high-temperature flame, thereby improving the sensitivity of the sample optical path.

[0047] The focusing fiber 37 is connected to the second chopper 35, which contains both the sample optical path and the reference optical path, and transmits the light source 1 to the monochromator 2. The focusing fiber 37 can have a tapered structure with a larger diameter at the front end and a smaller diameter at the rear end to improve the light focusing efficiency. The outer layer of the focusing fiber 37 is covered with a protective layer to prevent damage to the fiber from the external environment.

[0048] The implementation principle of the dual-optical-path atomic absorption device based on fiber optic spectroscopy in this application is as follows: Light emitted from a light source 1 is collected by a high-efficiency pickup head 31 and transmitted to a first chopper 34 via a splitting fiber 32. The first chopper 34 splits the optical path into a reference beam and a sample beam, and modulates the beam into parallel light through a focusing lens 33. Subsequently, a second chopper 35 periodically loads the light source 1, sequentially adjusting the optical path sequence to the element lamp sample path, the deuterium lamp 12 reference path, the element lamp reference path, and the deuterium lamp 12 sample path. The sample path uses an atomizer 36 to convert the analyte in the sample into an atomic state, thereby improving the sensitivity of the sample path. Finally, a converging fiber 37 converges the beam and transmits it to a monochromator 2, enabling quantitative analysis of the sample composition. This scheme, through optimized optical path design, improves detection stability and effectively subtracts background signals, solving the problems of large spectral energy loss and limited instrument space layout in traditional optical path designs.

[0049] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An atomic absorption dual-path device based on fiber optic beam splitting, characterized in that: include: Light source (1); Monochromator (2); The beam splitter (3) splits the light from the light source (1) into a sample light path and a reference light path, and transmits them to the monochromator (2). It includes a high-efficiency light pickup head (31), a beam splitter fiber (32), a focusing lens (33), a first chopper (34), a second chopper (35), an atomizer (36), and a converging fiber (37). The high-efficiency light pickup head (31) includes a light-collecting and focusing end (311) and a light-emitting end (312). The light-collecting and focusing end (311) is located at the light outlet of the light source (1). One end of the beam splitter fiber (32) is connected to the light-emitting end (312), and the other end is connected to the first chopper (34). The beam splitter is then connected to the first chopper (34) and passes through the first... The chopper (34) eliminates the background light and splits the beam into a reference light and a sample light. The back of the chopper is connected to the condenser lens (33), and the beam is modulated into parallel light through the condenser lens (33). The second chopper (35) is set behind the condenser lens (33). The second chopper (35) periodically loads the light source (1). The atomizer (36) is set inside the condenser lens (33) where the sample light path is located to improve the sensitivity of the sample light path. The converging fiber (37) is connected to the second chopper (35) where the sample light path and the reference light path are located, respectively, and transmits the light source (1) to the monochromator (2).

2. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 1, characterized in that: The light source (1) includes an element light box (11) and a deuterium lamp (12).

3. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 2, characterized in that: The optical fiber (32) includes a first optical fiber (321) connected to the element light box (11) and a second optical fiber (322) connected to the deuterium lamp (12). The first optical fiber (321) is used to transmit the light emitted by the element light box (11), and the second optical fiber (322) is used to transmit the light emitted by the deuterium lamp (12).

4. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 3, characterized in that: The first chopper (34) divides the optical path into the element lamp sample optical path, the element lamp reference optical path, the deuterium lamp (12) sample optical path and the deuterium lamp (12) reference optical path.

5. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 4, characterized in that: The second chopper (35) sequentially adjusts the light timing entering the monochromator (2) to: the sample light path of the element lamp, the reference light path of the deuterium lamp (12), the reference light path of the element lamp, and the sample light path of the deuterium lamp (12).

6. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 1, characterized in that: The diameter of the light-collecting and focusing end (311) is larger than the diameter of the light-emitting end (312).

7. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 6, characterized in that: A mirror coating is provided on the inner side of the pipe between the light-collecting and focusing end (311) and the light-emitting end (312).

8. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 1, characterized in that: The atomizer (36) is a flame head.

9. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 1, characterized in that: The monochromator (2) includes a slit and optical elements.

10. The atomic absorption dual-path device based on fiber optic beam splitting according to claim 1, characterized in that: It also includes a driver (313) that adjusts the position of the high-efficiency light-collecting head (31) and aligns the light-collecting and focusing end (311) with the light-emitting port of the light source (1).

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