Water-based wide-temperature-range scintillation liquid compound system and radioactivity detection method and sensor thereof

Abstract

The invention discloses a water-based wide-temperature-range scintillation liquid compound system and a radioactivity detection method and sensor thereof. The system is composed of a scintillator, a nonionic surfactant, an anionic surfactant, a zwitterionic surfactant, a cosolvent, a solvent and water in a synergistic manner. By regulating and controlling the length of a polymeric chain of the nonionic surfactant, the HLB value is accurately controlled, the surface tension is optimized, and efficient connection between a scintillation phase and a radionuclide water phase is achieved; the anionic surfactant reduces the phase interfacial tension and ensures that the components are uniformly dispersed; the zwitterionic surfactant dynamically adjusts the HLB value through the dissociation degree of a charge group, the dissociation degree of the charge group can change along with the temperature, and the stability of the micelle structure is dynamically adjusted in a wide temperature range. The scintillation liquid provided by the invention has excellent detection efficiency and extremely low detection limit, has outstanding water containing performance and temperature adaptability, and brings more efficient and accurate technical support to the field of radiation detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radionuclide detection materials and sensor technology, and particularly relates to a water-based wide-temperature-range scintillation liquid compounding system, a radionuclide detection method and a sensor. BACKGROUND

[0002] As a core material in the fields of nuclear radiation detection, particle physics experiments, environmental monitoring and medical imaging, scintillation liquid realizes the detection and analysis of radiation sources by converting the energy of radioactive particles into visible light signals. The global annual demand exceeds 5 million liters, and the market size exceeds 1 billion US dollars. However, the current high-performance scintillation liquid market mainly relies on imports, and there are problems such as long import cycle and high price (such as PerkinElmer's Ultima Gold LLT series). Under the influence of complex international situation and trade policy, it brings pressure and uncertainty to the development of domestic related industries.

[0003] Although the existing scintillation liquid technology has achieved certain breakthroughs in the field of radioactive detection, and the light output stability of some products in specific scenarios has reached the industry standard, there are still two significant bottlenecks when facing actual application scenarios: first, the current mainstream scintillation liquid generally has limited compatibility with water, and the water holding capacity is less than 40%. This means that when facing natural high-water-content samples such as blood, body fluids, and high-humidity soil, complicated dehydration or extraction treatment is required, which not only increases the detection cost but also may cause loss of radioactive substances due to the pretreatment process. Second, the stability of the current mainstream scintillation liquid in the conventional laboratory temperature range of <15℃ and >30℃ is poor. For example, in the summer high-temperature environment in the south, the surfactant micelles may collapse due to high-temperature dehydration, resulting in turbidity of the solution and a sharp drop in fluorescence efficiency. In the winter low-temperature environment in the north, the micelle structure may lose solubilizing ability due to low-temperature contraction, and the water phase is precipitated in the form of ice crystals, directly affecting the accuracy of the detection results. This "fear of heat in the south and fear of cold in the north" characteristic makes it difficult for the same batch of scintillation liquid to be used nationwide, especially in outdoor operations and cross-regional emergency monitoring scenarios, which requires separate customization of the formula for different regions, significantly increasing the technical application threshold.

[0004] Therefore, in view of the above problems, the present application provides a water-based wide-temperature-range scintillation liquid compounding system, a radionuclide detection method and a sensor, a high-performance scintillation liquid compounding system with wide-temperature-range adaptability, high water holding capacity and low detection limit, which effectively breaks through the multiple bottlenecks of existing technology in water compatibility, temperature range stability and detection sensitivity. SUMMARY

[0005] The present application aims at the multiple core defects of the prior art scintillation liquid, including insufficient water phase compatibility, limited temperature range stability, insufficient detection sensitivity, and significant scintillator self-quenching effect, and provides a water-based wide temperature range scintillation liquid compounding system, a radioactive detection method and a sensor thereof. The compounding system can be directly coupled with a radioactive detection sensor for use, and the uniform dispersion liquid formed by the system can closely contact the sensor detection end, reduce light signal loss, and enable the sensor to more efficiently capture the scintillation light converted from the radiation energy. The scintillation liquid provided by the present application not only improves the water phase volume accommodation capacity to 70%, which is nearly 80% higher than that of the current mainstream scintillation liquid product (such as Ultima Gold LLT), and realizes the homogeneous phase stability in the temperature range of 10℃-40℃; at the same time, by means of micelle solubilization and wavelength transfer technology, the detection limit of H is reduced to 3.66x10 3 Bq / mL, effectively breaking through the multiple bottlenecks of the prior art in water phase compatibility, temperature range stability and detection sensitivity, and having technical innovation and supply chain independence. -3 Bq / mL, effectively breaking through the multiple bottlenecks of the prior art in water phase compatibility, temperature range stability and detection sensitivity, and having technical innovation and supply chain independence.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] A radioactive detection method of a water-based wide temperature range scintillation liquid compounding system with synergistic effect of multiple surfactants, comprising the following steps:

[0008] S1, sample preparation: taking a water sample or a high water phase sample containing a target radionuclide, without dehydration or organic phase extraction treatment;

[0009] S2, scintillation liquid mixing: mixing the sample containing the target radionuclide and the water-based wide temperature range scintillation liquid compounding system with synergistic effect of multiple surfactants at a volume ratio of 1:1, stirring at a speed of 200-300 r / min for 10-30 seconds to form a uniform, clear and stable dispersion liquid system;

[0010] S3, detection condition setting: moving the uniform dispersion system obtained in step S2 into a liquid scintillation counting bottle, and placing it in a liquid scintillation counter integrated with a radioactive detection sensor (the radioactive detection sensor is a photoelectric sensing component adapted to scintillation light signals, and is used to capture visible light signals released by the scintillator); setting the detection temperature to 10℃-40℃, the photomultiplier tube voltage to 800-1200V, and the counting time to 1-10 minutes;

[0011] S4, signal acquisition and analysis: collecting the scintillation light signals by the radioactive detection sensor in the liquid scintillation counter, converting the light signals into electrical signals by the sensor, processing the electrical signals by a multichannel pulse analyzer, and finally calculating the activity concentration of the target radionuclide;

[0012] The synergistic water-based wide-temperature-range scintillation liquid complex system comprises the following components in percentage by mass:

[0013] The scintillator is 1-5%, the non-ionic surfactant is 20-45%, the anionic surfactant is 2-10%, the zwitterionic surfactant is 0.2-2%, the cosolvent is 3-20%, the solvent is 30-50%, and the water is 0.5-3%.

[0014] The scintillator is composed of a first scintillator and a second scintillator, the first scintillator is selected from one or more of 2,5-diphenyloxazole (PPO), 2-phenyloxazole (PO), 2,5-di(4-methylphenyl)oxazole (MPPO), p-terphenyl (TP) and 2-phenyl-5-(4-diphenyl)-1,3,4 oxazole (PBD), and the second scintillator is selected from one or more of 1,4-bis(2-methylstyryl)benzene (bis-MSB), 1,4-bis[2-(5-phenyl)oxazolyl]benzene (POPOP), 1,4-bis[2-(4-methyl-5-phenyloxazolyl)]-benzene (DMPOPOP) and 2-(4'-diphenyl)-6-phenylbenzoxazole (PBBO), and the amount of the second scintillator in the scintillator is 5%-20%, more preferably 1-2.5%.

[0015] Further preferably, the content of the scintillator is 1-2.5%.

[0016] Preferably, the mass ratio of the zwitterionic surfactant to the anionic surfactant is 1:8-40, so as to optimize the charge balance and micellar compactness.

[0017] Preferably, the detection limit of the system is ≤3.66×10- 3 Bq / mL, the wide-temperature-range adaptability is 10-40℃, and the water holding capacity is up to 70% (volume fraction).

[0018] Preferably, the amount of the non-ionic surfactant is 20-45%, more preferably 20-35%, and further preferably 30-35%.

[0019] Preferably, the non-ionic surfactant is selected from one or several of isomeric tridecyl alcohol polyoxyethylene (E / T0 series, such as E-1310 and T0-3, T0-8, T0-10), branched secondary alcohol polyoxyethylene (SA series, such as SA-9, SA-15), nonylphenol polyoxyethylene (NP / CO series, such as NP-40, CO-520 / 630 / 720), alkyl glycoside (APG series, such as APG0810, APG1214), polyoxyethylene polyoxypropylene block copolymer (Pluronic series, such as L64, F127), polyoxyethylene polyoxypropylene glyceryl ether (GPE-1025), fatty alcohol polyoxyethylene (AEO series, such as AEO-7, AEO-9), octylphenol polyoxyethylene (OP series, such as OP-10), polyoxyethylene lauryl ether (Brij series, such as Brij30, Brij52), polyethylene glycol monoalkyl ether (MPEG series, such as MPEG-200 and MPEG-400), and lauryl alcohol polyoxyethylene (MOA series, such as MOA-3).

[0020] Further preferably, the non-ionic surfactant is selected from one or several of nonylphenol polyoxyethylene (NP-10), nonylphenol polyoxyethylene (NP-40), polyoxaethylene (5) nonylphenyl ether (CO-520), polyoxaethylene (9) nonylphenyl ether (CO-630), and polyoxaethylene (12) nonylphenyl ether (CO-720), polyethylene glycol monoalkyl ether (T0-8), lauryl alcohol polyoxyethylene (MOA-3), isomeric tridecyl alcohol polyoxyethylene (X-100), and fatty alcohol polyoxyethylene (AEO-7).

[0021] Preferably, the amount of the anionic surfactant is 2-10%, more preferably 4-8%.

[0022] Preferably, the anionic surfactant is selected from one or several of sulfate ester salt, phosphate ester salt, carboxylate salt type, alkylbenzenesulfonate salt, a-olefin sulfonate salt, succinate sulfonate salt, alkyl glycoside phosphate ester, isomeric alcohol polyoxyethylene ether phosphate ester, fatty alcohol polyoxyethylene ether phosphate ester, and alkylphenol polyoxyethylene ether phosphate ester.

[0023] Further preferably, the anionic surfactant is selected from one or several of lauryl alcohol sulfate ammonium, alkylphenol ether phosphate potassium salt, sodium dodecylbenzenesulfonate, sodium dioctyl succinate sulfonate, APG-1214 phosphate ester, isomeric tridecyl alcohol ether phosphate ester (TXP-5), fatty alcohol polyoxyethylene ether phosphate ester (AEO-3P, AEO-9P), and alkylphenol polyoxyethylene ether phosphate ester (APE-4P, APE-10P).

[0024] Preferably, the amount of the zwitterionic surfactant is 0.2-2%, more preferably 0.3-0.5%.

[0025] Preferably, the zwitterionic surfactant is selected from one or more of the following: amino acid type, betaine type, imidazoline type, amine oxide type.

[0026] Further preferably, the zwitterionic surfactant is selected from one or more of the following: cocamidopropyl betaine (CAPB), dodecyldimethyl betaine (BS-12K), dodecyldimethyl sulfobetaine (SDBS-12), dodecylimidazoline sulfobetaine, and dodecyldimethyl amine oxide (OA-12).

[0027] Preferably, the cosolvent is selected from one or more of the following: high-boiling polar solvents, including diethylene glycol butyl ether, diethylene glycol hexyl ether, dipropylene glycol methyl ether, propylene glycol phenyl ether, tripropylene glycol n-butyl ether, tripropylene glycol monomethyl ether, and triethylene glycol methyl ether; more preferably, the cosolvent is diethylene glycol butyl ether and tripropylene glycol n-butyl ether.

[0028] Preferably, the amount of the cosolvent is 3-20%, more preferably 4-12%, and further preferably 8-10%; and the amount of diethylene glycol butyl ether and tripropylene glycol n-butyl ether is in a ratio of 8-20:1.

[0029] Preferably, the solvent is selected from one or more of the following: toluene, xylene, cyclohexane, n-hexane, 1,4-dichlorobenzene, methanol, ethanol, ethylene glycol, isopropanol, dimethyl sulfoxide, sulfolane, fluorinated hydrocarbon, decaline, and 2,6-diisopropyl naphthalene.

[0030] Further preferably, the solvent is 2,6-diisopropyl naphthalene, which has the characteristics of low fluorescence background interference, high energy transfer capacity, and strong resistance to polar substances such as water and alcohols.

[0031] Preferably, the small amount of pure water can interact with the hydrophilic group of the surfactant, stabilize the mixed micelle structure, adjust the hydrophilic-hydrophobic balance to improve the solubilizing capacity; at the same time, help the cosolvent to play a role, adjust the properties of the main solvent, and enhance the stability and fluidity of the system.

[0032] Preferably, the preparation method of the above-mentioned multi-component surfactant synergistic water-based wide-temperature-range scintillation liquid compounding system comprises the following steps:

[0033] (1) The first and second scintillators are added to a mixed solvent composed of a solvent and a cosolvent in a volume ratio of 2-4:1 under light-proof conditions at 25-30°C, and stirred at a stirring rate of 400-600 rpm or ultrasonically assisted at an ultrasonic power of 100-300 W for 15-60 min, the dissolving temperature is controlled at 25-30°C, and the dissolving time is 30-60 min;

[0034] (2) The nonionic surfactant, the zwitterionic surfactant and the anionic surfactant are sequentially added according to the ratio, the interval between the addition of each type of surfactant is 10-15 min, and a uniform solution system is formed by maintaining the stirring rate at 400-600 rpm, thereby obtaining the water-based wide-temperature-range scintillating liquid complex system with synergistic effect of the multi-component surfactants.

[0035] Preferably, in step (1), the dissolving step is ensured by temperature-controlled stirring to ensure complete dissolution of the scintillators, avoiding degradation of the scintillators due to local overheating.

[0036] Preferably, the ultrasonic assistance is used to achieve rapid and uniform dispersion of the scintillators.

[0037] Preferably, in step (2), the nonionic surfactant, the zwitterionic surfactant and the anionic surfactant are sequentially added in the order of nonionic surfactant, zwitterionic surfactant and anionic surfactant, and the interface adsorption layer formation efficiency is optimized by gradient addition sequence to improve the uniformity of the system.

[0038] Preferably, the water-based wide-temperature-range scintillating liquid complex system with synergistic effect of the multi-component surfactants can be further added with 0.1-0.5% of an antioxidant to improve the long-term storage stability.

[0039] Preferably, the length of the polymerization chain of the nonionic surfactant is regulated, the hydrophilic-lipophilic balance (HLB) value is precisely controlled, the liquid surface tension efficiency is optimized, the efficient connection between the scintillation phase and the water phase monolayer of the radionuclide is achieved, and the solubilizing capacity for the water phase is optimized.

[0040] Preferably, the anionic surfactant can promote uniform dispersion of each component by reducing the interfacial tension between different phases in the system, effectively avoiding phase separation and ensuring stable performance of the scintillating liquid.

[0041] Preferably, the zwitterionic surfactant can further fine-tune the overall HLB value of the system by the dissociation degree of the charge group, and the dissociation degree of the charge group can change with temperature, thereby dynamically adjusting the micelle structure stability in a wide temperature range.

[0042] Preferably, the cosolvent functions to adjust the polarity of the system by hydrogen bonding to combine with the scintillator molecules, improve the dissolution rate and dispersion uniformity of the scintillators, and avoid the decrease of fluorescence efficiency caused by insufficient dissolution.

[0043] Further, the scintillator functions as energy capture and fluorescence conversion, the first scintillator absorbs radiant energy, and the second scintillator shifts the wavelength to the visible light region; the non-ionic surfactant functions as forming a mixed micelle core, adjusting the HLB value, and improving the water phase solubilizing capacity; the anionic surfactant and the zwitterionic surfactant function as stabilizing the micelle interface charge in cooperation with the non-ionic surfactant; the cosolvent functions as optimizing solvent compatibility, and the solvent functions as a main solvent, which needs to have a low fluorescence background; and the water functions as optimizing the stability of the micelle structure.

[0044] The application also claims to protect a radioactivity detection sensor for implementing the above-mentioned detection method, comprising: a sample reaction module for mixing and stirring the water sample and the scintillation liquid complex system in proportion;

[0045] A constant temperature control module for keeping the mixed liquid after reaction at a constant temperature in a wide temperature range of 10℃ to 40℃;

[0046] An optical detection module comprising a photomultiplier tube for receiving a scintillation light signal, and the working voltage is 800-1200V;

[0047] A signal processing module for performing multi-channel pulse analysis on the collected light signal and calculating the radioactivity concentration.

[0048] Due to the use of the above technical solution, the application has the following beneficial effects compared with the prior art:

[0049] 1、The scintillation liquid complex system of the application can be applied to nuclear medical diagnosis, environmental pollution monitoring, nuclear waste monitoring and treatment, radiation safety detection, scientific research and other fields; especially for complex samples such as biological fluids and industrial wastewater with water content ≤70%, it can be directly detected without extraction pretreatment, meeting the precise detection requirements of wide temperature range (10℃-40℃) and high compatibility in multiple scenes;

[0050] 2、The application uses low-toxicity solvent 2,6-diisopropyl naphthalene (LD 50 >5000mg / kg, meeting the EU REACH standard) to replace traditional toxic aromatic hydrocarbons, and combines with multiple surfactants for synergistic complexing, realizing three major core performance breakthroughs: the water phase volume capacity reaches 70% (increased by 80% compared with imported products), stable and no stratification in the temperature range of 10℃-40℃, 3 H detection limit as low as 3.66×10 - 3 Bq / mL; at the same time, it has the characteristics of non-flammability and low volatility, and takes into account high performance and environmental friendliness;

[0051] 3、The application adopts domestic high-purity reagents to construct the formula, has excellent performance and reduces the cost compared with the imported one, significantly improves the market competitiveness, has simple and easy-to-operate preparation process, adapts to the production needs of large, medium and small enterprises, promotes the technological innovation of the domestic related industry, accelerates the progress of scientific research projects, and provides an efficient and economical solution for improving the international competitiveness of China's radioactivity detection field. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical features, objectives and effects of the present application, the following will describe the specific embodiments or prior art.

[0053] Figure 1 is the ultraviolet absorption spectrum of the scintillation liquid compounding system of the embodiment 1 of the present application;

[0054] Figure 2 is the fluorescence emission spectrum of the scintillation liquid compounding system of the embodiment 1 of the present application;

[0055] Figure 3 is the water holding capacity test chart of the scintillation liquid compounding system of the embodiment 1 of the present application and the imported Ultima Gold LLT scintillation liquid;

[0056] Figure 4 is the temperature stability test chart of the scintillation liquid compounding system of the embodiment 1 of the present application and the imported Ultima Gold LLT scintillation liquid;

[0057] Figure 5 is the drawing of the preparation of the quenching standard curve of the embodiment 1 of the present application;

[0058] Figure 6 is the water holding capacity test chart of the scintillation liquid of the embodiment 1 of the present application and the comparative examples 1-6. DETAILED DESCRIPTION

[0059] In order to have a more clear understanding of the technical features, objectives and effects of the present application, the specific embodiments will be described in detail.

[0060] The present application will be further described below in combination with the embodiments, but the present application is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to different requirements of specific use, and the implementation conditions marked are the conventional conditions in the industry. The technical features involved in each embodiment of the present application can be combined with each other as long as there is no conflict.

[0061] Embodiment 1

[0062] Reference is made to the drawingsFigure 1 -attach Figure 6 The embodiment provides a radioactive detection method of a multi-surfactant synergistic water-based wide-temperature-range scintillation liquid complex system, and comprises the following steps:

[0063] S1, sample preparation: taking a water sample or a high-aqueous-phase sample containing a target radionuclide, without dehydration or organic phase extraction treatment;

[0064] S2, scintillation liquid mixing: mixing the sample containing the target radionuclide and the multi-surfactant synergistic water-based wide-temperature-range scintillation liquid complex system according to a volume ratio of 1:1, stirring at a rotating speed of 300 r / min for 20 seconds, and forming a uniform, clear and stable dispersion liquid system;

[0065] S3, detection condition setting: moving the uniform dispersion system obtained in the step S2 into a liquid scintillation counting bottle, placing the liquid scintillation counting bottle in a liquid scintillation counter, setting a detection temperature as 30 DEG C, setting a voltage of a photomultiplier tube as 1000 V, and setting a counting time as 5 minutes;

[0066] S4, signal collection and analysis: collecting a scintillation light signal through the liquid scintillation counter, processing the scintillation light signal through a multichannel pulse analyzer, and calculating an activity concentration of the target radionuclide;

[0067] The scintillator is composed of a first scintillator and a second scintillator, the first scintillator is 2,5-diphenyloxazole (PPO), and the second scintillator is 1,4-bis (2-methylstyryl) benzene (bis-MSB);

[0068] The non-ionic surfactant is polyoxaethylene (5) nonyl phenyl ether (CO-520);

[0069] The anionic surfactant is alkylphenol polyoxyethylene ether phosphate APE-10P;

[0070] The amphoteric surfactant is dodecyl dimethyl betaine;

[0071] The cosolvent is selected from high-boiling-point polar solvents, and the cosolvent is diethylene glycol butyl ether and tripropylene glycol n-butyl ether;

[0072] The solvent is 2,6-diisopropyl naphthalene;

[0073] The preparation method of the multi-surfactant synergistic water-based wide-temperature-range scintillation liquid complex system comprises the following steps:

[0074] (1) 0.5 g of the first scintillator PPO and 0.05 g of the second scintillator bis-MSB were added to 8 g of 2,6-diethylpropyl naphthalene, 2 g of diethylene glycol butyl ether, 0.25 g of tripropylene glycol n-butyl ether and 0.5 g of pure water to form a mixed solvent under the conditions of light shielding at 25°C and stirring at 500 rpm for 30 min until complete dissolution;

[0075] (2) 7 g of non-ionic surfactant polyoxyethylene (5) nonyl phenyl ether (CO-520), 0.1 g of zwitterionic surfactant dodecyl dimethyl betaine and 1.6 g of anionic surfactant alkyl phenol polyoxyethylene ether phosphate APE-10P were sequentially added, with an interval of 12 min for each type of surfactant, while maintaining the stirring rate at 500 rpm, to form a uniform solution system, thereby obtaining the multi-surfactant synergistic water-based wide temperature range scintillation liquid complex system.

[0076] The multi-surfactant synergistic water-based wide temperature range scintillation liquid complex system prepared in Example 1 was tested, and the details are as follows:

[0077] Test 1: Absorption spectrum test: The self-developed scintillation liquid prepared in Example 1 was diluted 100 times to prepare a test mother liquor. The mother liquor was diluted 100 times and placed in a fluorescence cuvette for testing. The absorption spectrum of the newly prepared scintillation liquid system was measured using a UV spectrophotometer, as shown in Figure 1 .

[0078] Test 2: Fluorescence emission spectrum test: The self-developed scintillation liquid prepared in Example 1 was diluted 100 times to prepare a test mother liquor. The mother liquor was diluted 100 times and placed in a fluorescence cuvette for testing. The fluorescence emission spectrum of the newly prepared scintillation liquid system was measured using a fluorescence spectrophotometer, as shown in Figure 2 .

[0079] Test 3: Water holding capacity test: The water holding capacity test of the self-developed scintillation liquid of the present application and the imported Ultima Gold LLT scintillation liquid: The scintillation liquid prepared in Example 1 and the imported Ultima Gold LLT scintillation liquid were respectively configured with distilled water in different proportions, and the corresponding water content at which milky white turbidity appeared was observed, thereby testing the maximum water holding capacity of the two scintillation liquids; as shown in Figure 3 , the maximum water holding capacity of the new scintillation liquid system was about 70%, while the maximum water holding capacity of the imported Ultima Gold LLT scintillation liquid was only about 40%.

[0080] Test 4: Temperature Stability Test: Temperature stability test of the self-developed scintillation fluid of this invention and the imported Ultima Gold LLT scintillation fluid: Take 0.5 mL each of the scintillation fluid prepared in Example 1 and the imported Ultima Gold LLT scintillation fluid, and add 0.5 mL of water to prepare colorless and transparent homogeneous solutions. Place the two homogeneous solutions in water baths at 10℃, 15℃, 20℃, 25℃, 30℃, 35℃ and 40℃ respectively. Figure 4 As shown, the novel scintillation fluid system of this invention maintains a clear and transparent homogeneous solution state throughout the entire temperature range of 10℃ to 40℃, exhibiting excellent wide-temperature stability. In contrast, the imported UltimaGold LLT scintillation fluid exhibits obvious turbidity and stratification at 40℃, with a sharp drop in transmittance, indicating that its high-temperature adaptability has significant defects.

[0081] Test 5: Plotting the quenching standard curve: using PerkinElmer. 3 H standard sources (10 series quenched and 1 unquenched source) were used to detect sources with known activity using an ultra-low background liquid scintillation spectrometer (LSA-3000) with a built-in high-resolution radioactivity detection sensor. Eleven different efficiency count values ​​were obtained based on the ratio of the detected activity to the known activity of the source. Furthermore, quenching relationship curves were obtained based on the TDCR value (triple detection efficiency ratio, which measures the triple coincidence and double coincidence count rates of three PMTs, i.e., Nt and Nd; TDCR is the ratio of the three-tube to two-tube coincidence count rates, Nt / Nd). Figure 5 As shown.

[0082] Test 6: Detection Efficiency (E%) Test: Detection efficiency (E%) test of the self-developed scintillation fluid of this invention and the imported Ultima Gold LLT scintillation fluid: Take 20 mL each of the scintillation fluid prepared in Example 1 and the imported Ultima Gold LLT scintillation fluid, and place them in a low-background fluorescent glass bottle for testing. Add 100 Bq of radioactive solution dissolved in n-hexadecane to each bottle. 3 H is used as the radiation source; the counting efficiency measurements of the self-developed scintillation fluid and the imported Ultima Gold LLT scintillation fluid of this invention are shown in Table 1. According to the measured TDCR value, when substituted into the FSI quenching relationship curve prepared in test 5, the counting efficiencies of the scintillation fluids are 57.68% and 56.56%, respectively; the prepared novel scintillation fluid has higher detection efficiency.

[0083] Table 1

[0084]

[0085]

[0086] Test 7: Background value (Nd) test: The background value (Nd) test of the self-developed scintillation solution of the application and the imported Ultima Gold LLT scintillation solution: take 20 mL of the scintillation solution configured in Example 1 and 20 mL of the imported Ultima Gold LLT scintillation solution, and put them into a low-background fluorescent glass bottle for testing, then put them into LSA-3000, and select count analysis and CPM measurement in the measurement mode; then enter the energy spectrum analysis interface, select start, and the instrument starts automatic measurement to obtain the background values of the self-developed scintillation solution and the imported LLT scintillation solution under natural conditions, which are 20.83 cpm and 20.69 cpm respectively. The background value of the self-developed new scintillation solution is almost the same as that of the imported Ultima Gold LLT scintillation solution.

[0087] Test 8: Detection limit (MDA) test: The detection limit (MDA) test of the self-developed scintillation solution of the application and the imported Ultima Gold LLT scintillation solution: take 12 mL of the scintillation solution configured in Example 1 and 12 mL of the imported Ultima Gold LLT scintillation solution, dissolve them in 8 mL of water, and then put them into a low-background fluorescent glass bottle for testing, then follow the steps of Test 6 and Test 7 to measure the detection efficiency and background value of the scintillation solution under long time (more than 1000 min), and the detection limit of the self-developed scintillation solution of the application and the imported Ultima Gold LLT scintillation solution is shown in Table 2.

[0088] Table 2

[0089]

[0090] According to the internationally recognized formula:

[0091]

[0092] Wherein the value of K is related to the specified accuracy, usually taking 3, T s and T b are the measurement time of the sample and the background respectively; n b is the background count rate (cpm), E% is the count efficiency, and V (mL) is the actual volume of the pure sample to be tested.

[0093] When the sample measurement time is long, the term (K / T s ) 2 can be omitted, and K = 3 is taken, then the formula is further simplified as:

[0094]

[0095] The detection lower limit of the self-made scintillation solution and the imported Ultima Gold LLT scintillation solution can be calculated by substituting the values, which are 3.66 Bq / L and 4.89 Bq / L respectively. The self-made scintillation solution has a lower detection lower limit than the imported Ultima Gold LLT scintillation solution.

[0096] Test 9: Anti-quenching ability test: The anti-quenching ability test of the self-made scintillation solution of the application and the imported Ultima Gold LLT scintillation solution: 20 mL of the scintillation solution configured in Example 1 and 20 mL of the imported Ultima Gold LLT scintillation solution were taken and placed in low-background fluorescent glass bottles for testing, 100 Bq of radioactive activity of toluene dissolved in n-hexadecane was added to each of them, and 50 μL of carbon tetrachloride was added as a quenching agent; the count efficiency measurement of the self-made scintillation solution of the application and the imported Ultima Gold LLT scintillation solution after adding the quenching agent is shown in Table 3. According to the FSI quenching relationship curve made by substituting the measured TDCR value in Test 5, the count efficiency of the self-made scintillation solution and the imported Ultima Gold LLT scintillation solution after adding the quenching agent is 33.75% and 33.54% respectively, and there is no significant difference in anti-quenching performance between the two. 3 H as a radioactive source, and the choice of radionuclide 3 H, and 50 μL of carbon tetrachloride was added as a quenching agent; the count efficiency measurement of the self-made scintillation solution of the application and the imported Ultima Gold LLT scintillation solution after adding the quenching agent is shown in Table 3. According to the FSI quenching relationship curve made by substituting the measured TDCR value in Test 5, the count efficiency of the self-made scintillation solution and the imported Ultima Gold LLT scintillation solution after adding the quenching agent is 33.75% and 33.54% respectively, and there is no significant difference in anti-quenching performance between the two.

[0097] Table 3

[0098] Sample name Nt Nd TDCR E％ Self-made scintillation solution 1237.21 3792.02 0.3263 33.75 Imported Ultima Gold LLT scintillation solution 1122.39 3563.75 0.3149 33.54

[0099] Comparative Example 1

[0100] This comparative example is based on the above-mentioned Example 1, and the same parts as the above-mentioned Example 1 are not described again.

[0101] In this comparative example, only a non-ionic surfactant is added.

[0102] Comparative Example 2

[0103] This comparative example is based on the above-mentioned Example 1, and the same parts as the above-mentioned Example 1 are not described again.

[0104] In this comparative example, only a zwitterionic surfactant is added.

[0105] Comparative Example 3

[0106] This comparative example is based on the above-mentioned Example 1, and the same parts as the above-mentioned Example 1 are not described again.

[0107] In this comparative example, only an anionic surfactant is added.

[0108] Comparative Example 4

[0109] This comparative example was carried out on the basis of the above-mentioned Example 1, and the same parts as in the above-mentioned Example 1 are not described herein again.

[0110] In this comparative example, only nonionic surfactant and zwitterionic surfactant were added.

[0111] Comparative Example 5

[0112] This comparative example was carried out on the basis of the above-mentioned Example 1, and the same parts as in the above-mentioned Example 1 are not described herein again.

[0113] In this comparative example, only zwitterionic surfactant and anionic surfactant were added.

[0114] Comparative Example 6

[0115] This comparative example was carried out on the basis of the above-mentioned Example 1, and the same parts as in the above-mentioned Example 1 are not described herein again.

[0116] In this comparative example, only nonionic surfactant and anionic surfactant were added.

[0117] The components and the amounts of addition of Example 1 and Comparative Examples 1 to 6 are listed in Table 4.

[0118] Table 4

[0119]

[0120]

[0121] The scintillation solutions of Example 1 and Comparative Examples 1 to 6 were subjected to water holding capacity test by using the test method described in Test 3. Strictly in accordance with the “water holding capacity test method” of Test 3, under the condition of 25℃ room temperature, equal volume of deionized water was added to each of the scintillation solution systems of the comparative examples and the scintillation solution of the self-developed example, so that the volume ratio of the water phase reached 50%. By comparing and observing the turbidity degree and phase separation phenomenon of the system, the difference in water phase solubilizing capacity of different surfactant compounding schemes was evaluated.

[0122] Figure 6 The water holding capacity comparison results of Example 1 and Comparative Examples 1 to 6 are intuitively presented. Under the condition of 25℃ room temperature, Example 1 was clear and transparent at 50% water content, without stratified turbidity phenomenon; while Comparative Examples 1 to 6 all showed obvious turbidity and stratification phenomenon at 50% water content, and white flocculent precipitate was visible in the system. This experimental phenomenon fully shows that the scintillation solution of the comparative examples using single or binary surfactant compounding cannot effectively solubilize the water phase medium, while the synergistic compounding system of multiple surfactants proposed in the present application constructs a more stable supramolecular micellar network, which significantly improves the water phase holding capacity of the scintillation solution.

[0123] The above results effectively verify the uniqueness and innovation of the complex design of the present application in breaking through the technical bottlenecks of traditional technology. Not only does it break through the technical bottlenecks of traditional single / dual surfactant systems in water capacity and temperature stability, but it also significantly improves the detection efficiency under high water phase ratio conditions, providing a new material solution for the radiation detection field with environmental adaptability and reliable detection.

[0124] In summary, the scintillation liquid complex system of the present application can be applied to multiple fields such as nuclear medical diagnosis, environmental pollution monitoring, nuclear waste monitoring and processing, radiation safety detection, and scientific research. Especially for complex samples such as biological fluids with water content ≤70% and industrial wastewater, direct detection without extraction pretreatment can meet the precise detection requirements of wide temperature range (10℃-40℃) and high compatibility in multiple scenarios. The present application uses low-toxicity solvent 2,6-diisopropyl naphthalene (LD 50 >5000mg / kg, meeting the EU REACH standard) to replace traditional toxic aromatic hydrocarbons, combined with multi-surfactant synergistic complex, to achieve three major performance breakthroughs: water phase volume capacity up to 70% (80% higher than imported products), stable without stratification in 10℃-40℃ temperature range, 3 H detection limit as low as 3.66x10 -3 Bq / mL; at the same time, it is not flammable and has low volatility, balancing high performance and environmental friendliness; the present application uses domestic high-purity reagents to construct the formula, which has excellent performance and lower cost than imported products, significantly improving market competitiveness; the preparation process is simple and easy to implement, suitable for the production needs of large, medium and small enterprises, promoting technological innovation in the domestic related industry, accelerating the progress of scientific research projects, and providing an efficient and economical solution for improving the international competitiveness of China's radiation detection field.

[0125] The above-described embodiments only express one embodiment of the present application, which is described in more detail and in more detail, but should not be construed as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A radioactive detection method of a multi-surfactant synergistic water-based wide temperature range scintillation liquid compounding system, characterized in that, It comprises the following steps: S1, sample preparation: take the water sample or high water phase sample containing the target radionuclide without dehydration or organic phase extraction treatment; S2, mixing of scintillation liquid: mix the sample of target radionuclide and the multi-surfactant synergistic water-based wide temperature range scintillation liquid complex system according to the volume ratio of 1:1, stir at the speed of 200-300 r / min for 10-30 seconds to form a uniform, clear and stable dispersion liquid system; S3, setting of detection conditions: move the uniform dispersion system obtained in step S2 into a liquid scintillation counting bottle and place it in a liquid scintillation counter, set the detection temperature to 10-40℃, the voltage of photomultiplier tube to 800-1200V, and the counting time to 1-10 minutes; S4, signal acquisition and analysis: collect the scintillation light signal through the liquid scintillation counter, and calculate the activity concentration of the target radionuclide after processing by a multichannel pulse analyzer; The multi-surfactant synergistic water-based wide temperature range scintillation liquid complex system comprises the following components in mass percentage: The scintillator is composed of a first scintillator and a second scintillator, the first scintillator is selected from one or more of 2,5-diphenyloxazole, 2-phenyloxazole, 2,5-di(4-methylphenyl)oxazole, p-terphenyl and 2-phenyl-5-(4-diphenyl)-1,3,4 oxazole; the second scintillator is selected from one or more of 1,4-bis(2-methylstyryl)benzene, 1,4-bis[2-(5-phenyl)oxazolyl]benzene, 1,4-bis[2-(4-methyl-5-phenyloxazolyl)]-benzene and 2-(4'-diphenyl)-6-phenylbenzoxazole; the amount of the second scintillator in the scintillator is 5%-20%. The mass ratio of the amphoteric surfactant to the anionic surfactant is 1:8-40.

2. The method for radioassay of the multi-surfactant synergistic water-based wide temperature range scintillation fluid compounding system according to claim 1, characterized in that, The non-ionic surfactant is selected from one or more of isomeric tridecanol polyoxyethylene ether, branched secondary alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, alkyl glycoside, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene polyoxypropylene glycerol ether, fatty alcohol polyoxyethylene ether, octylphenol polyoxyethylene ether, polyoxyethylene lauryl ether, polyethylene glycol monoalkyl ether and lauryl alcohol polyoxyethylene ether.

3. The method for radioassay of the multi-surfactant synergistic water-based wide temperature range scintillation fluid compounding system according to claim 1, characterized in that, The detection limit of the system is ≤ 3.66 x 10- 3 The system has a detection limit of ≤ 3.66 x 10- 4. The method for radioassay of the multi-surfactant synergistic water-based wide temperature range scintillation fluid compounding system according to claim 1, characterized in that, The anionic surfactant is selected from one or more of sulfate ester salt, phosphate ester salt, carboxylate salt type, alkyl benzene sulfonate, alpha-olefin sulfonate, succinate sulfonate, alkyl glycoside phosphate, isomeric alcohol polyoxyethylene ether phosphate, fatty alcohol polyoxyethylene ether phosphate and alkyl phenol polyoxyethylene ether phosphate.

5. The method for radioassay of the multi-surfactant synergistic water-based wide temperature range scintillation fluid compounding system of claim 1, wherein, The amphoteric surfactant is selected from one or more of amino acid type, betaine type, imidazoline type and amine oxide type.

6. The method for radioassay of the multi-surfactant synergistic water-based wide temperature range scintillation fluid compounding system of claim 1, wherein, ​ 7. The method for radioassay of the multi-surfactant synergistic water-based wide temperature range scintillation fluid compounding system of claim 1, wherein, The co-solvent is selected from one or more of high-boiling polar solvents, including diethylene glycol butyl ether, diethylene glycol hexyl ether, dipropylene glycol methyl ether, propylene glycol phenyl ether, tripropylene glycol n-butyl ether, tripropylene glycol monomethyl ether, and triethylene glycol methyl ether.

8. The method for radioassay of the multi-surfactant synergistic water-based wide temperature range scintillation fluid compounding system of claim 1, wherein, The solvent is selected from one or more of toluene, xylene, cyclohexane, n-hexane, 1,4-dichlorobenzene, methanol, ethanol, ethylene glycol, isopropyl alcohol, dimethyl sulfoxide, sulfolane, fluorinated hydrocarbon, decalin, and 2,6-diisopropyl naphthalene.

9. A radiation detection sensor for implementing the detection method according to any one of claims 1 to 8, characterized by The method comprises the following steps: a sample reaction module for mixing and stirring the water sample and the scintillation liquid compounding system in proportion; a constant temperature control module for keeping the mixed liquid after reaction at a constant temperature in a wide temperature range of 10-40℃; an optical detection module comprising a photomultiplier tube for receiving a scintillation light signal, and the working voltage is 800-1200V; a signal processing module for multi-channel pulse analysis of the collected light signal and calculation of the radioactivity concentration.

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