Cold digestion iodine detection method and extremely violet colorimetric system

Abstract

The invention discloses a cold digestion iodine detection method and an extremely violet light colorimetric system.According to the cold digestion iodine detection method, 382 + / -8 nm extremely violet light is adopted to replace blue light to conduct colorimetric analysis on a sample obtained after cold digestion, and the extremely violet light colorimetric system replaces a light source of an existing blue light colorimetric mechanism with an extremely violet light source. An LED lamp wick can be directly used as a light source of the extreme purple light source, and the extreme purple light source is smaller in size and more reasonable in layout. According to the method, extremely purple light is adopted to replace blue light to detect the iodine sample after cold digestion, and the detection precision is closer to that of an arsenic-cerium redox spectrophotometer method.

Description

Technical Field

[0001] The invention belongs to the technical field of medical detection, and in particular relates to a cold digestion iodine detection method and an extreme ultraviolet light colorimetric system. Background Art

[0002] At present, the chemical methods for iodine detection are respectively the thermal digestion iodine detection method and the cold digestion iodine detection method. The high-temperature thermal digestion method is adopted (the high-temperature thermal digestion adopted by the arsenic cerium redox spectrophotometer method recommended by the health industry standard), and the process is cumbersome and the experimental cycle is long, which may limit the application in large-scale screening or rapid detection. In addition, the detection personnel need to contact toxic reagents, which poses a safety risk. In actual experimental operation, the time requirement is very strict, and the detection personnel need to carefully perform each step of the operation. It is easy to cause the detection failure due to human factors, and it is necessary to manually record the data to calculate the results. The cold digestion iodine detection method can realize the cold digestion and automatic detection under the fully automatic room temperature environment. At present, the cold digestion iodine element detector equipment on the market generally uses a blue light detection device, and the frequency band used by the blue light is 450-495nm, but there is a certain gap between the detection results of the existing blue light detection device and the thermal decomposition method. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a cold digestion iodine detection method that can use extreme violet light instead of blue light colorimetry to test iodine samples based on the cold digestion method, and its detection results are closer to the detection results of the arsenic cerium redox spectrophotometer method than the blue light detection.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a cold digestion iodine detection method, after adding a reducing agent, an indicator and an oxidizing agent to the iodine sample after cold digestion in sequence, extreme violet light colorimetric detection is used to determine the iodine content in the iodine sample, and the extreme violet light wavelength is 382±8nm.

[0005] The wavelength of the extreme ultraviolet light described in the above technical solution is 382nm.

[0006] The reducing agent described in the above technical solution is a sodium arsenite aqueous solution.

[0007] The indicator in the above technical solution is an aqueous solution of sulfuric acid of Ferroin's reagent.

[0008] The oxidant in the above technical solution is a sulfuric acid aqueous solution of tetravalent cerium.

[0009] A second object of the present invention is to provide an extreme ultraviolet light colorimetric system which has a simple structure and uses extreme ultraviolet light to perform colorimetric detection on iodine samples.

[0010] In order to achieve the above-mentioned purpose, the technical solution of the present invention is as follows: an extreme ultraviolet light colorimetric system, used for application in the cold digestion iodine detection method as described above, comprising a bracket, an extreme ultraviolet light emitting device and an optical signal receiving device, wherein the extreme ultraviolet light emitting device and the optical signal receiving device are spaced and arranged oppositely on the bracket, and a cuvette is placed between the extreme ultraviolet light emitting device and the optical signal receiving device.

[0011] In the above technical solution, there are multiple extreme violet light emitting devices and multiple optical signal receiving devices, and the multiple extreme violet light emitting devices and the multiple optical signal receiving devices correspond one to one. The multiple extreme violet light emitting devices and the multiple optical signal receiving devices are distributed in rows respectively, and the corresponding extreme violet light emitting devices and optical signal receiving devices are used to place cuvettes.

[0012] The extreme purple light emitting device described in the above technical solution includes an LED wick, a focal column and a plano-convex lens arranged in sequence.

[0013] The optical signal receiving device in the above technical solution includes a filter, a dark box and a photoresistor. The photoresistor is arranged in the dark box. The dark box has a light inlet window aligned with the extreme ultraviolet light emitting device. The filter is installed at the light inlet window.

[0014] The filter element described in the above technical solution is a filter plate.

[0015] The beneficial effects of the present invention are as follows: (1) In the use of the original cold digestion iodine element detection equipment, a blue light colorimetric system is used. When the detection point is set, it is found that in the case of complex samples, the error variability of the detection is large, and the peak value of the detection value cannot be used for verification detection. At the same time, the detection value under the detection of the same equipment has a large drift. The present invention finds that the cold digestion color change state is the most accurate detection value when the purple changes instantly to dark red as the interception time point. In actual detection, it is found that the detection is carried out using an extreme purple (frequency band between 374-390nm) light source. In the colorimetric detection, the detection voltage has a peak value, which can accurately reflect the instantaneous change of the purple end point of the detection. The peak point is highly consistent with the actual detection value. The peak change time of the extreme purple color is the best time to calculate the iodine concentration. However, when using a blue colorimetric system, the colorimetric acceptance state change value changes gradually from a high value to a low value, and its peak value is relatively gentle, and the peak interception time cannot be determined. For example, when the positioning point is about 2 / 3 of the blue drop, that is, 3.2V, it actually causes the positioning point to drift easily, and the time of the point cannot be accurate, resulting in inaccurate detection of the fixed point value, and the detection value often deviates; (2) Since the extreme purple light source can be directly replaced by an LED wick, which is compact in size, its corresponding multi-link extreme purple light colorimetric system can be made even smaller in size. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a detection diagram of the iodine sample after cold digestion by extreme ultraviolet light in Example 1 of the present invention;

[0017] Figure 2 This is a detection diagram of the iodine sample after cold digestion by blue light in Example 1 of the present invention;

[0018] Figure 3 This is a schematic diagram of the structure of the extreme ultraviolet colorimetric system described in Example 2 of the present invention;

[0019] Figure 4 It is a vertical view of the extreme ultraviolet colorimetric system described in Example 2 of the present invention;

[0020] Figure 5 It is a cross-sectional view of the extreme ultraviolet colorimetric system described in Example 2 of the present invention.

[0021] In the figure: 1. bracket; 11. placement slot; 2. extreme ultraviolet light emitting device; 21. LED wick; 22. focal column; 23. plano-convex lens; 3. optical signal receiving device; 31. filter element; 32. dark box; 321. light inlet window; 33. photoresistor; 4. cuvette. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0023] Example 1

[0024] The present embodiment provides a cold digestion iodine detection method, after adding a reducing agent, an indicator and an oxidant to the iodine sample after cold digestion in sequence, an extreme purple light with a wavelength of 382±8nm (specifically, it can be any value of 374nm, 375nm, 376nm, 377nm, 378nm, 379nm, 380nm, 381nm, 382nm, 383nm, 384nm, 385nm, 386nm, 387nm, 388nm, 389nm and 390nm or a range corresponding to any two values, preferably 382nm) is used for colorimetric detection to determine the iodine content in the iodine sample, wherein the reducing agent is an aqueous solution of sodium arsenite, the indicator is an aqueous solution of sulfuric acid of Ferroin's reagent, and the oxidant is an aqueous solution of sulfuric acid of tetravalent cerium. The iodine sample described in this embodiment can be urine iodine, blood iodine, water iodine or salt iodine. When the iodine sample is blood iodine, its cold digestion method and the concentration and addition amount of the reducing agent, indicator and oxidant can all refer to the contents disclosed in the document number CN113340888B "Reagents, kits and detection methods for quantitative detection of blood iodine". When the sample to be detected is blood iodine or water iodine, its cold digestion method and the concentration and addition amount of the reducing agent, indicator and oxidant can all refer to the contents disclosed in the document number CN110320207A "A reagent and detection method for detecting iodine element". When detecting salt iodine, the salt iodine needs to be dissolved in water and fixed to volume, and then the detection can be carried out in the same way as water iodine.

[0025] The blue light method and the extreme violet light method in this embodiment were used to detect the standard sample with an iodine concentration of 120ug / L, respectively. Three parallel experiments were performed for each method. The specific wavelength of the extreme violet light was 382nm and the wavelength of the blue light was 465nm.

[0026] Three extreme ultraviolet light experimental groups (such as Figure 1 The output voltage value of the extreme purple light 1, extreme purple light 2 and extreme purple light 3) changes with time as shown in the curve Figure 1 As shown by Figure 1 It can be seen that the peak time consistency of the extreme ultraviolet 382nm light source is good. Figure 2 The output voltage value of blue light 1, blue light 2 and blue light 3) changes with time as shown in the curve Figure 2 As shown by Figure 2 It can be seen that the blue light method uses 465nm to detect the peak value (5.0V) and the time drift deviation occurs at the position of 3.20V.

[0027] in, Figure 2 The two red horizontal thick lines in the middle are used to represent the two comparison voltages of 3.2V and 5.0V respectively. Under these two comparison voltages, the three blue light experimental groups all showed time drift under these two comparison voltages.

[0028] Figure 1 and Figure 2 The horizontal axis is time, in seconds (s), and the vertical axis is voltage, in V.

[0029] Twelve iodine samples with different concentrations were tested using arsenic-cerium redox spectrophotometer method, blue light method and extreme violet light method. The test results are shown in Table 1:

[0030] Table 1 Comparison of the test results of three detection methods

[0031]

[0032] Among them, the deviation coefficients of the detection results of the extreme ultraviolet light method and the blue light method are compared with the detection results of the arsenic cerium redox spectrophotometer method.

[0033] In the experiment of cold digestion detection of iodine samples, it was found in this embodiment that when the extreme purple light method was used, the color end point was selected at the moment when the purple turned dark red, which just accurately intercepted the end point reaction time of iodine in urine at the moment when the extreme purple dropped to the peak, and it was also the moment when it turned red, which was very suitable as the end point. Its detection value was more accurate than that of the blue light method.

[0034] Example 2

[0035] like Figure 3-Figure 5 As shown, this embodiment provides an extreme violet light colorimetric system for use in the cold digestion iodine detection method as described above, including a bracket 1, an extreme violet light emitting device 2 and an optical signal receiving device 3, wherein the extreme violet light emitting device 2 and the optical signal receiving device 3 are spaced and arranged relatively on the bracket 1, and a cuvette 4 is placed between the extreme violet light emitting device 2 and the optical signal receiving device 3. Specifically, the extreme violet light emitting device 2 and the optical signal receiving device 3 each have a plurality, and the plurality of the extreme violet light emitting devices 2 and the plurality of the optical signal receiving devices 3 correspond one to one, and the plurality of the extreme violet light emitting devices 2 and the plurality of the optical signal receiving devices 3 are respectively arranged in rows, and the corresponding extreme violet light emitting devices 2 and the optical signal receiving devices 3 are used to place the cuvette 4. In this embodiment, the extreme violet light emitting devices 2 and the optical signal receiving devices 3 are both arranged in a plurality and correspond one to one, so that the entire extreme violet light colorimetric system can detect multiple samples at the same time, such as the number of the extreme violet light emitting devices 2 and the optical signal receiving devices 3 can be 4-10, of course, but not limited thereto.

[0036] The extreme violet light emitting device 2 in the above technical solution includes an LED wick 21, a focal column 22 and a plano-convex lens 23 arranged in sequence, wherein the extreme violet light beam emitted by the LED wick 21 is processed by the focal column 22 and the plano-convex lens 23 and then projected to the corresponding optical signal receiving device; the optical signal receiving device 3 includes a filter 31, a dark box 32 and a photoresistor 33, the photoresistor 33 is arranged in the dark box 32, and the dark box 32 has a light inlet window 321 aligned with the extreme violet light emitting device 2, the filter 31 is installed at the light inlet window 321, the filter only allows the extreme violet light emitted by the corresponding extreme violet light emitting device 2 to pass (filter out stray light), the photoresistor is used to sense the light intensity in the dark box and output a voltage value, and the iodine concentration can be converted according to the size of the voltage value. Preferably, the filter can use a filter plate, which is used to only allow light of the wavelength corresponding to the light beam emitted by the extreme violet light emitting device 2 to pass.

[0037] In the above technical solution, a placement groove 11 is recessed on the bracket 1 between the extreme ultraviolet light emitting device 2 and the optical signal receiving device 3, and the bottom end of the cuvette 4 is used to fall into the placement groove 11 for limiting position.

[0038] In this embodiment, multiple extreme violet light emitting devices 2 are provided, but when multiple LED wicks are independent light sources, there will be deviations between the light sources. If the original blue light colorimetric mechanism wants to detect multiple samples at the same time, the luminous values ​​of multiple light sources must be as uniform as possible, and the error can be reduced when 3.2V is taken at the same time (this is more difficult to do, so most of them are emitted by the same light source and divided into multiple beams, but the splitting optical path is more complicated and the volume is larger, which ultimately makes the device larger). However, in this embodiment, the extreme violet light colorimetric system uses peak calculation time. Although the peak voltage of each detection path has errors due to different light sources, it only needs to read When each sample reaches its peak value, the instant when the iodine detection changes color can be calculated by the program. At the same time, each photoresistor of the optical signal receiving device can automatically adjust the output voltage of the optical signal receiving device using the voltage feedback circuit, that is, the multiple extreme purple light detection units in this embodiment (the corresponding extreme purple light emitting device 2 and the optical signal receiving device 3 constitute an extreme purple light detection unit) can operate independently without interfering with each other, and have high sensitivity. It can detect multiple samples to be detected at the same time, so that the detection system has efficient parallel processing capabilities, greatly shortens the detection time, thereby shortening the time patients wait for test results and improving work efficiency.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A cold digestion iodine detection method, characterized in that, After adding a reducing agent, an indicator and an oxidizing agent to the cold-digested iodine sample in sequence, extreme violet light colorimetric detection is used to determine the iodine content in the iodine sample, wherein the wavelength of the extreme violet light is 382±8 nm.

2. The cold digestion iodine detection method according to claim 1, characterized in that, The extreme ultraviolet light has a wavelength of 382 nm.

3. The cold digestion iodine detection method according to claim 1, characterized in that, The reducing agent is a sodium arsenite aqueous solution.

4. The cold digestion iodine detection method according to claim 1, characterized in that: The indicator is a sulfuric acid aqueous solution of Ferroin's reagent.

5. The cold digestion iodine detection method according to claim 1, characterized in that, The oxidant is a sulfuric acid aqueous solution of tetravalent cerium.

6. An extreme violet colorimetric system, used in the cold digestion iodine detection method according to any one of claims 1 to 5, characterized in that: The invention comprises a bracket (1), an extreme violet light emitting device (2) and an optical signal receiving device (3), wherein the extreme violet light emitting device (2) and the optical signal receiving device (3) are arranged on the bracket (1) in a spaced manner and opposite to each other, and a cuvette (4) is placed between the extreme violet light emitting device (2) and the optical signal receiving device (3).

7. The extreme ultraviolet colorimetric system according to claim 6, characterized in that: The extreme violet light emitting device (2) and the optical signal receiving device (3) are both provided in plurality, and the plurality of the extreme violet light emitting devices (2) and the plurality of the optical signal receiving devices (3) correspond one to one, the plurality of the extreme violet light emitting devices (2) and the plurality of the optical signal receiving devices (3) are respectively arranged in rows, and the corresponding extreme violet light emitting devices (2) and the optical signal receiving devices (3) are used to place a cuvette (4).

8. The extreme ultraviolet colorimetric system according to claim 6 or 7, characterized in that: The extreme purple light emitting device (2) comprises an LED lamp core (21), a focal length column (22) and a plano-convex lens (23) which are arranged in sequence.

9. The extreme ultraviolet colorimetric system according to claim 6 or 7, characterized in that: The optical signal receiving device (3) comprises a filter element (31), a dark box (32) and a photoresistor (33); the photoresistor (33) is arranged in the dark box (32); the dark box (32) has a light inlet window (321) aligned with the extreme ultraviolet light emitting device (2); and the filter element (31) is installed at the light inlet window (321).

10. The extreme ultraviolet colorimetric system according to claim 9, characterized in that: The filter element (31) is a filter plate.

Images