Detection device and method for high absorbance liquids

Abstract

A detection device and method for high-absorbance liquids include: a detection light source (using an LED), a light source correction module (correcting divergent light into parallel light), a short-path optical container (containing a liquid sample of a substance with high molar absorptivity), and a photodetector. The detection light source is positioned at the focal point of the light source correction module. After the corrected parallel light passes through the sample in the short-path optical container, the photodetector receives the transmitted light and converts it into an electrical signal, which is then used by computer software to calculate the sample absorbance and substance concentration. This invention achieves high precision, high stability, and a high signal-to-noise ratio detection through light source correction and a short-path design, making it particularly suitable for the detection of high-absorbance liquids and substances with high molar absorptivity.

Description

[Technical Field]

[0001] This invention relates to a detection device and method for high absorbance liquids, used to detect liquids containing substances with high molar absorption. [Previous Technology]

[0002] In the field of food and environmental testing, liquid optical measurement technology is widely used to detect the concentration of various chemical substances. However, for the detection of substances with high molar absorption rates (such as caffeine, chlorogenic acid, trigonelline, etc.), there are some technical challenges in practical applications.

[0003] In practical applications, the detection light source is an LED, but LEDs produce divergent light, causing uneven light path through the sample. The instability of the light source directly affects the reliability of the measurement results. In addition, high molar absorptivity materials have very strong absorption in the UVC band, which may lead to excessively low detection signals or signals exceeding the detection range.

[0004] The traditional method to solve the above problem is to dilute the sample in order to reduce the absorbance, but this method increases the complexity of operation and may affect the accuracy of detection, especially when precise measurement of low concentration samples is required. [Summary of the Invention]

[0005] To solve the above problems, the present invention provides a detection device and method for high absorbance liquids, which uses an aspherical lens to correct the detection light source and uses a short optical path optical container to reduce the absorbance of high molar substances, thereby improving the accuracy of optical detection.

[0006] Technical features of the present invention:

[0007] A detection device for high absorbance liquid, comprising:

[0008] A detection light source, which is an LED;

[0009] A light source correction module corrects the divergent light of the detection light source into parallel light; the detection light source is located at the focal position on the incident light side of the light source correction module;

[0010] A short optical path optical container for containing a liquid sample with high absorbance; the short optical path optical container is disposed on the light-emitting side of the light source correction module and located on the path of the parallel light; the parallel light is incident from the first side of the short optical path optical container, passes through the liquid sample, and is transmitted from the second side of the short optical path optical container.

[0011] A photodetector is disposed on the second side of the short optical path optical container. The photodetector receives the transmitted light and converts it into an electrical signal for computer software to calculate the absorbance of the liquid sample and the concentration of the high molar absorptivity substance.

[0012] A method for detecting a high absorbance liquid, comprising the following steps:

[0013] A detection light source is provided: an ultraviolet LED;

[0014] Correct the divergent light of the detection light source: Correct the divergent light of the detection light source into parallel light through a light source correction module;

[0015] Setting up a short optical path optical container: A high-absorbency liquid sample is placed in the short optical path optical container, and the short optical path optical container is positioned in the optical path of the parallel light, allowing the parallel light to pass through the liquid sample; the optical path of the short optical path optical container is 0.1 cm to 0.5 cm; and

[0016] Detection of transmitted light signal: A photodetector is used to receive the transmitted light passing through the liquid sample and convert it into an electrical signal, which is then used by computer software to calculate the concentration of the high molar absorptivity substance.

[0017] Effects of the invention:

[0018] High precision and stability: The light source correction module uses a Fresnel lens to correct the divergent light emitted by the LED into parallel light, ensuring the consistency of the optical path when the light passes through the sample under test, reducing the impact of optical path variation on the measurement, and significantly improving the stability and accuracy of the measurement. In addition, the short optical path optical container shortens the optical path (0.1cm to 0.5cm), reduces the absorption of light by the highly absorbent liquid, and ensures that the light can effectively penetrate the sample, further improving the accuracy and stability of the measurement.

[0019] Improved signal-to-noise ratio (SNR): When the corrected parallel light passes through the sample, it can reduce the scattering and reflection of light within the sample, thereby improving the signal-to-noise ratio (SNR).

[0020] Suitable for substances with high molar absorption: Using short-wave ultraviolet light as the detection light source, it is particularly suitable for detecting substances with high molar absorption (such as caffeine, chlorogenic acid, trigonelline, etc.) and can effectively detect the concentration of these substances.

[0021] Flexibility and adjustability: By adjusting the thickness of the metal plate or selecting cuvettes with different optical paths, the length of the optical path can be precisely controlled to meet the detection needs of samples with different absorbance.

[0022] High-efficiency automated detection process: The photodetector converts transmitted light into electrical signals, which are then used by computer software to calculate the absorbance and concentration of the sample, thus achieving a high-efficiency and automated detection process.

[0023] Wide applicability: This invention is not only applicable to liquids with high absorbance, but also to various fields that require precise optical measurement, such as chemical analysis, biological detection, food detection, etc.

[0024] Multi-band scalability: Although the present invention mainly uses the UVC band, its design principle can be extended to other optical bands, and has a wide range of application potential. [Simplified Explanation of the Diagram]

[0049] [Figure 1] Schematic diagram of an embodiment of the short optical path optical container of the detection device of the present invention.

[0050] [Figure 2] Schematic diagram of a second embodiment of the short optical path optical container of the detection device of the present invention.

Implementation Method

[0025] The embodiments of the present invention will be described below with reference to the accompanying drawings and examples. The illustrations provided in the following examples are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the type, quantity, proportion and layout of each component can be changed.

[0026] As shown in Figures 1 and 2, the present invention provides a detection device for a high absorbency liquid, comprising: a detection light source 10, a light source correction module 20, a short optical path optical container 30, and a photodetector 40.

[0027] Regarding the detection light source 10, an LED is used. To detect substances with high molar absorptivity, a short-wave ultraviolet (UVC) LED with a wavelength of 273nm is used.

[0028] Regarding the light source correction module 20, the divergent light emitted by the LED is corrected into parallel light to improve measurement stability and accuracy. This embodiment of the invention uses an aspherical lens, preferably a Fresnel lens. Because LEDs typically have a large divergence angle (e.g., 120°), the light path becomes uneven when passing through the sample under test, thus affecting the measurement results. By placing the detection light source 10 at the focal point on the incident light side of the Fresnel lens, the divergent light emitted by the detection light source 10 is corrected into parallel light after refraction by the annular structures of the lens, thereby ensuring optical path consistency and effectively reducing the impact of optical path variation on the measurement. When this parallel light passes through the sample under test, it can significantly reduce the scattering and reflection of light within the sample, further improving the signal-to-noise ratio (SNR), which is particularly crucial for the detection of weak light signals, such as in optical measurement applications in the UVC band (273nm).

[0029] The short-path optical container 30 is an optical container for holding a high-absorbance liquid sample (a liquid sample containing a substance with high molar absorptivity). It is located on the light-emitting side of the light source correction module 20 and on the path of the parallel light. The core of the short-path optical container 30 is to reduce absorbance by shortening the path length (optical path) of light through the sample, ensuring that light can effectively penetrate the sample, thereby improving the accuracy and stability of the measurement.

[0030] As shown in Figure 1, regarding the short optical path optical container 30, in one embodiment of the present invention, it is preferably a short optical path cuvette 31. The optical path of the short optical path cuvette 31 is 0.1cm to 0.5cm.

[0031] As shown in Figure 2, in another embodiment of the short-path optical container 30 of the present invention, it includes a metal plate 32 and two light-transmitting sheets 322 covering both sides of the metal plate 32. The metal plate 32 includes at least one through-hole 321, which penetrates the metal plate 32 in a direction parallel to the thickness T of the metal plate 32. The through-hole 321, together with the two light-transmitting sheets 322, forms a closed sample cell 321 for containing a high-absorbency liquid sample. Channels (not shown) can be opened from other directions of the metal plate 32 to connect to the through-hole 321 (sample cell 321) to facilitate the injection or pouring of liquid samples into the through-hole 321 (sample cell 321).

[0032] The thickness T of the metal plate 32 determines the optical path length; the thinner the thickness T, the shorter the optical path, and vice versa. In the preferred embodiment of the present invention, the thickness T of the metal plate 32 is 0.1cm to 0.5cm. This length meets the purpose of a short optical path, and the optical path length can be precisely controlled by adjusting the thickness T of the metal plate 32. The specific thickness T depends on the application requirements. The material of the metal plate 32 should have good optical reflectivity and corrosion resistance. Common materials include, but are not limited to, stainless steel and aluminum alloy. The cross-sectional shape and size of the through hole 321 determine the path of light. The cross-sectional shape of the through hole 321 can be circular, square, or rectangular. Furthermore, the cross-sectional size of the through hole 321 should be larger than the thickness T of the metal plate 32 so that the formed sample cell 321 can accommodate a sufficient amount of liquid sample. The through hole 321 can be manufactured by laser cutting, CNC machining, etc., and the edges of the through hole 321 should be smooth to reduce light scattering. In practical applications, metal plates 32 of various thicknesses T can be prepared, and the selection can be made according to the absorbance of the sample.

[0033] Regarding the two light-transmitting sheets 322 covering both sides of the metal plate 32, their material is selected from quartz, glass, or transparent plastic, and their thickness T is 1mm~2mm to reduce light loss. Quartz is preferred because it has extremely high transmittance to ultraviolet light (especially the UVC band, 273nm), effectively transmitting UVC light and reducing light loss. Furthermore, quartz has excellent chemical resistance, resisting corrosion from most acids, alkalis, and organic solvents, making it very suitable for liquid sample detection. Quartz also has low spontaneous fluorescence in the ultraviolet band, which helps reduce background noise and improve the signal-to-noise ratio (SNR). In addition, the light-transmitting sheet 322 must have a flat surface to ensure a consistent light path, reducing light scattering and reflection, and further improving measurement accuracy.

[0034] The aforementioned parallel light is incident from the first side 323 of the short optical path optical container 30, passes through the liquid sample in the sample cell 321, and is transmitted from the second side 324 of the short optical path optical container 30.

[0035] Regarding the photodetector 40, it is located on the second side 324 of the short optical path optical container 30. The photodetector 40 receives the transmitted light passing through the liquid sample and converts it into an electrical signal so that the computer software 50 can further calculate the absorbance of the sample and the concentration of substances with high molar absorptivity (such as caffeine, chlorogenic acid, trigonelline, etc.).

[0036] Based on the above-described apparatus, the present invention provides a method for detecting high absorbance liquids, comprising the following steps:

[0037] Provide detection light source 10: Use short-wave ultraviolet (UVC) LED as light source, with a wavelength of 273nm;

[0038] Correcting the divergent light of the detection light source 10: Correcting the divergent light of the LED into parallel light through the light source correction module 20;

[0039] A short-path optical container 30 is provided: a liquid sample containing a substance with high molar absorptivity is placed in the short-path optical container 30, and the short-path optical container 30 is positioned in the optical path of the parallel light, so that the parallel light passes through the liquid sample; the optical path of the short-path optical container 30 is 0.1 cm to 0.5 cm; and

[0040] Detecting transmitted light signal: The photodetector 40 receives the transmitted light after passing through the liquid sample, converts it into an electrical signal, and provides the computer software 50 with the ability to calculate the sample absorbance and the concentration of the high molar absorptivity substance.

[0041] Hereinafter, the feasibility of the present invention will be verified by experimental results.

[0042] Test sample: coffee liquid.

[0043] Test conditions: A UVC light source was used for testing. Coffee liquid was contained in both a conventional cuvette (1 cm optical path) and a short-path cuvette 31 (0.1 cm optical path). Conventional UVC light is diffused LED light; this invention uses a Fresnel lens to correct the UVC light into parallel light. Finally, the measurement data from the conventional method and this invention were compared to observe signal stability.

[0044] Experimental results: Caffeine and chlorogenic acid in coffee liquid are substances with high molar absorptivity, which was verified in the experiment of this invention. It is proved that the detection light source 10, after being modified to parallel light, can improve signal stability when combined with short optical path cuvette 31. The technology of this invention is applicable to the detection of liquids containing substances with high molar absorptivity.

[0045] Table 1 shows the signal detected by using different concentrations of coffee liquid at different wavelengths, with water as a blank control. The data shows that the signal change is significantly increased after using a Fresnel lens.

[0046] Table 1

[0047] Experimental results of this technology demonstrate that by using UVC band optical measurement and short optical path control technology, the measurement accuracy of substances with high absorption coefficients can be effectively improved, and it can be applied to the fields of food and environmental testing.

Claims

1. A detection device for a high absorbance liquid, comprising: The detection light source is a short-wave ultraviolet (UVC) LED; A light source correction module corrects the divergent light from the detection light source into parallel light; The detection light source is located at the focal point of the light incident side of the light source correction module; a short-path optical container is used to hold a high-absorbency liquid sample; the short-path optical container is located on the light emitting side of the light source correction module and is situated in the path of the parallel light; the parallel light is incident from the first side of the short-path optical container, passes through the liquid sample, and is transmitted from the second side of the short-path optical container; a photodetector is located on the second side of the short-path optical container, the photodetector receives the transmitted light and converts it into an electrical signal for computer software to calculate the... The absorbance of a liquid sample and the concentration of a substance with high molar absorptivity; characterized in that: the short optical path optical container includes a metal plate and two light-transmitting sheets covering both sides of the metal plate; the metal plate includes at least one through hole, the through hole penetrating the metal plate in a direction parallel to the thickness of the metal plate, the through hole and the two light-transmitting sheets forming a sample cell for containing the liquid sample; the thickness of the metal plate is 0.1cm to 0.5cm; the material of the two light-transmitting sheets is selected from quartz, glass, or transparent plastic, and the thickness is 1mm to 2mm.

Images