A method for detecting copper oxide content in a gas generator using a chemical sensor

Abstract

This invention provides a method for detecting copper oxide content in a gas generator using a chemical sensor. During copper ion detection, the test solution contains coumarin compounds with phenylhydrazone groups. These compounds, acting as a chemical sensor, can complex with copper ions. This complexation weakens the carbon-nitrogen double bonds in the phenylhydrazone compound molecules, promoting the hydrolysis of the phenylhydrazone groups to generate corresponding aldehyde compounds. The solution then emits a strong green fluorescence. When used for copper ion detection in aqueous solutions, the chemical sensor of this invention exhibits a significant fluorescence enhancement response, high detection sensitivity, and a detection limit as low as 150 nM. It demonstrates extremely high selectivity for copper ions with almost no interference from other common metal ions, and is particularly effective in accurately quantifying the content and distribution of copper oxide in gas generators.

Description

Technical Field

[0001] This invention relates to the field of environmental monitoring technology, and in particular to a method for detecting the copper oxide content in a gas generator using a chemical sensor. Background Technology

[0002] Airbag gas generators are composite energetic materials containing multiple functional components. Each component has different flow characteristics, density, and surface properties. Therefore, a mixing process is necessary to ensure sufficient contact between the different components, resulting in a faster and more complete combustion reaction. The uniformity of the mixture directly affects the performance of the gas generator. Improving the uniformity of the mixture maximizes gas generation efficiency. In actual production, a suitable mixing method must be selected based on the gas generator's solubility, density, sensitivity, and other physicochemical properties, as well as production costs.

[0003] In airbag gas generators, copper oxide (CuO) plays an indispensable role, whether as an oxidant, a composite oxidant, or a catalyst. The amount of copper oxide added and the uniformity of mixing with other components have a crucial impact on the combustion performance of the agent, thus affecting the performance of the gas generator and the airbag. Traditional methods generally characterize the distribution and composite effect of the components in the gas generator through elemental analysis, scanning electron microscopy, and inductively coupled plasma atomic emission spectrometry. However, these methods have drawbacks such as cumbersome sample preparation, complex instrument operation, low accuracy, and inability to eliminate interference from coexisting ions. In addition, to evaluate different mixing processes and parameters, pressure performance tests, flame tests, and residue tests are generally performed after the gas generator and gas generator are matched, which are cumbersome, costly, and time-consuming.

[0004] Therefore, establishing a simple, efficient, and accurate method for measuring the mixing uniformity of the components of a gas generator is of great significance for evaluating different mixing processes. Summary of the Invention

[0005] In view of this, this application provides a method for detecting the copper oxide content in a gas generator using a chemical sensor, in order to solve the technical problems of existing methods for detecting the copper oxide content in gas generators, such as cumbersome operation, high cost, and long time consumption.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] To achieve the above technical objectives, this application adopts the following technical solution:

[0008] This invention provides a method for detecting the copper oxide content in a gas generator using a chemical sensor, comprising:

[0009] S10, Different volumes of copper ion standard solution are gradually added to the test solution, and the fluorescence intensity of the mixed solution after each addition is tested; The test solution includes coumarin compounds containing phenylhydrazone groups;

[0010] S20, a standard curve was plotted based on the relationship between copper ion concentration and fluorescence intensity changes;

[0011] S30, the test sample solution is quantitatively added to the test solution to obtain the reaction solution, and the fluorescence intensity of the reaction solution is tested; the test sample solution is prepared by dissolving, diluting and making up to volume a gas generator containing copper oxide;

[0012] S40, based on the standard curve and the fluorescence intensity of the reaction solution, quantitatively analyze the concentration of copper ions in the sample solution to be tested.

[0013] Preferably, the preparation method of the test solution in step S10 includes the following steps:

[0014] Coumarin compounds containing aldehyde groups, 4-methoxyphenylhydrazine, and anhydrous ethanol were mixed and subjected to an anaerobic heating and reflux reaction.

[0015] After the anaerobic heating and reflux reaction is completed, the mixture is naturally cooled to room temperature, and the crude product is obtained by removing anhydrous ethanol by vacuum distillation.

[0016] The crude product was purified by column chromatography to obtain coumarin compounds containing phenylhydrazone groups;

[0017] A test solution is prepared by mixing a coumarin compound containing a phenylhydrazone group, an organic solvent, and a buffer solution.

[0018] Preferably, the molar ratio of the aldehyde-containing coumarin compound to 4-methoxyphenylhydrazine is 1:(1.2~2.5); the molar ratio of the aldehyde-containing coumarin compound to anhydrous ethanol is 1g:(30~100)mL.

[0019] Preferably, in the anaerobic heating reflux reaction, the reaction atmosphere is an inert atmosphere, the reflux reaction temperature is 80~90℃, and the reflux reaction time is 6~7h.

[0020] Preferably, the organic solvent includes any one of dimethyl sulfoxide, acetonitrile, tetrahydrofuran, N,N-dimethylformamide and acetone, and the buffer solution includes 4-hydroxyethylpiperazine ethanesulfonic acid.

[0021] Preferably, the concentration of coumarin compounds containing phenylhydrazone groups in the test solution is 5 × 10⁻⁶. -7 ~1×10 -5 mol / L; the volume ratio of buffer solution to organic solvent is (1~50):5, and the pH value of the buffer solution is 5.5~10.

[0022] Preferably, the coumarin compounds containing a phenylhydrazone group include structures as shown in structural formula (I):

[0023] (I).

[0024] Preferably, in step S20, a standard curve is obtained by linearly fitting the change in fluorescence intensity at 490 nm corresponding to different copper ion concentrations as the ordinate and the copper ion concentration as the abscissa.

[0025] Preferably, step S30 further includes the following step:

[0026] Random samples were taken from the same batch of gas-generating agent columns and thoroughly ground to obtain solid agent samples.

[0027] The solid sample of the reagent was dissolved in nitric acid, filtered through a microfilter to remove insoluble impurities, and then diluted and brought to volume with deionized water to obtain the sample solution to be tested.

[0028] The fluorescence emission spectra of the reaction solution were tested sequentially. The distribution of copper was characterized by the changing trends of the fluorescence emission spectra, and the uniformity of the mixing of each component material in the gas generator was finally evaluated.

[0029] Preferably, the process after step S40 further includes:

[0030] The copper content in the sample solution was accurately determined using a standard curve and compared with the reagent formulation.

[0031] Beneficial Effects: This invention provides a method for detecting copper oxide content in a gas generator using a chemical sensor. During copper ion detection, the test solution contains coumarin compounds with phenylhydrazone groups. These compounds, acting as a chemical sensor, can complex with copper ions. This complexation weakens the carbon-nitrogen double bonds in the coumarin molecules, promoting the hydrolysis of the phenylhydrazone groups to generate corresponding aldehyde compounds, which in turn cause the mixed solution to emit strong green fluorescence. Furthermore, when the chemical sensor of this invention is used to detect copper ions in aqueous solutions, it exhibits a significant fluorescence enhancement response, high detection sensitivity, and a detection limit as low as 150 nM. It also demonstrates extremely high selectivity for copper ions with almost no interference from other common metal ions, and is particularly effective in accurately quantifying the content and distribution of copper oxide in gas generators. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of a method for detecting copper oxide content in a gas generator using a chemical sensor, provided in an embodiment of this application.

[0033] Figure 2The fluorescence titration diagrams of the test solution provided in Example 1 of this invention with standard solutions of copper ions of different concentrations are shown.

[0034] Figure 3 The graph shows the linear relationship between the fluorescence intensity change at 490 nm and the copper ion concentration of the test solution provided in Example 1 of this invention.

[0035] Figure 4 The image shows the recognition response of the test solution provided in Example 1 of this invention to copper ions when common interfering ions coexist.

[0036] Figure 5 The fluorescence spectrum change trend of the test sample solution prepared by adding gas generators produced by different mixing processes to the test solution provided in Example 1 of the present invention;

[0037] Figure 6 The fluorescence emission spectrum of the test sample solution after adding a gas generator produced by a pneumatic mixing process to the test solution provided in Example 1 of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] Chemical sensors are a class of molecular devices with "reporting" capabilities. They can change their properties based on the presence of a target analyte, thereby achieving specific recognition and detection of guest molecules. Among them, fluorescence technology, as an emerging detection method, has become the mainstream in chemical sensor design due to its high sensitivity, fast response speed, and low detection limit.

[0040] Therefore, this invention proposes a high-performance chemical sensor that utilizes ingenious molecular design and organic synthesis to achieve rapid, accurate, and highly sensitive detection of copper oxide content in gas generators. By testing the copper oxide content in different parts of the reagent, the influence of different mixing processes on the uniformity of material mixing can be determined, providing a convenient, fast, and reliable evaluation method for selecting mixing processes and setting mixing parameters in actual industrial production.

[0041] Specifically, unless otherwise specified in this invention, conditions shall be performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0042] Please see Figure 1 , Figure 1A schematic flowchart of a method for detecting copper oxide content in a gas generator using a chemical sensor, provided in an embodiment of this application; wherein the method includes the following steps:

[0043] S10, gradually add different volumes of copper ion standard solution to the test solution and test the fluorescence intensity of the mixed solution after each addition; the test solution includes coumarin compounds containing phenylhydrazone groups.

[0044] Specifically, step S10 also includes:

[0045] First, the test solution is prepared, and the preparation method includes the following steps:

[0046] Coumarin compounds containing aldehyde groups, 4-methoxyphenylhydrazine, and anhydrous ethanol were mixed and subjected to an anaerobic heating and reflux reaction.

[0047] After the anaerobic heating and reflux reaction is completed, the mixture is naturally cooled to room temperature, and the crude product is obtained by removing anhydrous ethanol by vacuum distillation.

[0048] The crude product was purified by column chromatography to obtain coumarin compounds containing phenylhydrazone groups;

[0049] A test solution is prepared by mixing a coumarin compound containing a phenylhydrazone group, an organic solvent, and a buffer solution.

[0050] Specifically, the molar ratio of aldehyde-containing coumarin compounds to 4-methoxyphenylhydrazine is 1:(1.2~2.5); the molar ratio of aldehyde-containing coumarin compounds to anhydrous ethanol is 1g:(30~100)mL; this setting can ensure the reaction is complete and avoid side reactions.

[0051] Specifically, coumarin compounds containing a phenylhydrazone group include structures as shown in structural formula (I):

[0052] (I).

[0053] Specifically, the chemical reaction equation for the anaerobic heating reflux reaction is as follows:

[0054] ;

[0055] The reaction atmosphere is inert, the reflux reaction temperature is 80~90℃, and the reflux reaction time is 6~7h.

[0056] Furthermore, aldehyde-containing coumarin compounds and some intermediates in the reaction process may possess certain oxidizing or reducing properties, potentially reacting with oxygen in air, leading to a decrease in product purity and yield. In an inert atmosphere (such as nitrogen or argon), these unnecessary oxidation reactions can be avoided, ensuring the reaction proceeds in a purer environment, thereby improving reaction selectivity and product quality.

[0057] Furthermore, a reflux reaction temperature of 80–90°C provides sufficient energy for the reaction, allowing the aldehyde-containing coumarin compounds to fully react with 4-methoxyphenylhydrazine. Too low a temperature will result in a very slow reaction rate, potentially leading to incomplete reactions; too high a temperature may trigger side reactions, such as compound decomposition. On the other hand, anhydrous ethanol has a boiling point of approximately 78°C, and a temperature of 80–90°C, close to or slightly higher than the boiling point of ethanol, is conducive to forming a stable reflux state, ensuring thorough mixing of the substances in the reaction system, and improving the homogeneity and efficiency of the reaction.

[0058] Furthermore, if the reaction time is too short, the aldehyde-containing coumarin compounds may not react fully with 4-methoxyphenylhydrazine, resulting in a low product yield. If the reaction time is too long, it not only wastes time and energy but may also cause further reactions in the product, generating impurities and reducing product purity. Experimental verification has shown that a reaction time of 6-7 hours ensures product yield while minimizing side reactions, resulting in better reaction performance.

[0059] Specifically, the organic solvent includes any one of dimethyl sulfoxide, acetonitrile, tetrahydrofuran, N,N-dimethylformamide, and acetone, and the buffer includes 4-hydroxyethylpiperazine ethanesulfonic acid (HEPES).

[0060] Specifically, the volume ratio of buffer solution to organic solvent is (1~50):5, and the pH of the buffer solution is 5.5~10. This appropriate volume ratio ensures that coumarin compounds containing phenylhydrazone groups are fully dissolved in the mixed system and participate in any subsequent reactions. The organic solvent dissolves the compound, while the buffer solution maintains the chemical stability of the system. Within a pH range of 5.5~10, coumarin compounds containing phenylhydrazone groups maintain a relatively stable structure, reducing decomposition or structural changes caused by acidic or alkaline environments. For example, excessive acidity (pH below 5.5) may cause protonation of the phenylhydrazone group, affecting the compound's fluorescence properties; excessive alkalinity (pH above 10) may lead to side reactions such as hydrolysis of the coumarin structure.

[0061] Specifically, the concentration of coumarin compounds containing phenylhydrazone groups in the test solution was 5 × 10⁻⁶. -7 ~1×10 -5The concentration range is specified as mol / L; this range falls within the optimal sensitivity range for fluorescence detection. Coumarin compounds inherently possess fluorescence properties. Excessively high concentrations may lead to excessively high fluorescence intensity, exceeding the instrument's linear detection range and resulting in inaccurate measurements. Conversely, excessively low concentrations result in weak fluorescence signals, easily influenced by background noise, also failing to yield accurate and reliable detection data. Within this concentration range, however, fluorescence intensity exhibits a good linear relationship with compound concentration, facilitating accurate analysis of compound content changes through fluorescence intensity measurement.

[0062] Specifically, the column chromatography packing material is silica gel or Al2O3; the column chromatography eluent is a mixture of dichloromethane, ethyl acetate and methanol, with a volume ratio of (5~10):1:(0.1~0.5).

[0063] In one embodiment, a test solution comprising a coumarin compound containing a phenylhydrazone group is obtained through the following steps:

[0064] The concentration range of 1×10⁻⁶ is prepared using organic solvents. -4 ~1×10 -1 A stock solution of coumarin compounds containing phenylhydrazone groups was prepared at a concentration of mol / L, and then diluted to 5 × 10⁻⁶ mol / L using buffer and organic solvent. -7 ~1×10 -5 The test solution was obtained by applying a concentration of mol / L.

[0065] Specifically, the organic solvent can be dimethyl sulfoxide, acetonitrile, tetrahydrofuran (THF), N,N-dimethylformamide, acetone, etc., and the present invention does not limit it; the buffer can be 4-hydroxyethylpiperazine ethanesulfonic acid (HEPES) buffer, and the pH value of the buffer is 5.5~10.

[0066] Furthermore, in the test solution, the volume ratio of buffer solution to organic solvent ranges from (1 to 50): 5.

[0067] Next, different volumes of copper ion standard solution were gradually added to the test solution, mixed thoroughly, and the emission spectrum was measured using a fluorescence spectrophotometer. The fluorescence intensity of the mixed solution was also measured after each addition.

[0068] Specifically, the preparation process of the copper ion standard solution is as follows: weigh a certain mass of analytical grade copper salt, add deionized water to dissolve it completely, and obtain the copper ion standard solution; the analytical grade copper salt can be CuCl2 and Cu(NO3)2, etc., and this invention does not limit it.

[0069] Specifically, during the process of testing the emission spectra of copper ion standard solutions and test solutions of different concentration gradients using a fluorescence spectrophotometer, the excitation wavelength was 410 nm.

[0070] The detection process in step S10 is as follows: The carbonyl and nitrogen atoms in the coumarin compound (I) with the phenylhydrazone group can complex with copper ions. This complexation weakens the C=N double bond in compound (I), making it more attractive to water molecules and promoting the hydrolysis of compound (I) to generate an aldehyde compound (II). The solution emits a strong green fluorescence. The specific process is as follows:

[0071] .

[0072] The key technology of this invention lies in the fact that, compared with ketone carbonyl groups, aldehyde compounds have less steric hindrance, which is more conducive to the nucleophilic attack of 4-methoxyphenylhydrazine, greatly improving the reaction yield of the target compound (I). The complexation of copper ions with the phenylhydrazone group in compound (I) weakens the C=N bond, which is more conducive to the subsequent hydrolysis reaction, significantly improving the detection sensitivity. Generally speaking, due to the heavy metal quenching effect of copper ions, constructing fluorescence-enhanced copper ion sensors is quite challenging. Here, however, by utilizing the complexation of copper ions to induce the hydrolysis reaction of phenylhydrazone compounds to generate aldehyde compounds with strong fluorescence, a new idea and method for constructing fluorescence-enhanced copper ion sensors is provided.

[0073] S20, a standard curve was plotted based on the relationship between copper ion concentration and fluorescence intensity changes.

[0074] Specifically, step S20 also includes:

[0075] In this study, a standard curve was obtained by testing the fluorescence spectrum response of a test solution containing a benzohydrazone group to a standard copper ion solution, and obtaining the relationship between copper ion concentration and fluorescence intensity. The standard curve was obtained by linearly fitting the fluorescence intensity change at 490 nm of mixed solutions containing different copper ion concentrations to the ordinate and the copper ion concentration to the abscissa.

[0076] S30, the test sample solution is quantitatively added to the test solution to obtain the reaction solution, and the fluorescence intensity of the reaction solution is tested; the test sample solution is prepared by dissolving, diluting and making up to volume a gas generator containing copper oxide.

[0077] Specifically, step S30 also includes:

[0078] First, the sample solution to be tested is prepared, and the preparation method is as follows:

[0079] Random samples were taken from the same batch of gas-generating agent columns and thoroughly ground to obtain solid agent samples.

[0080] The solid sample of the reagent was dissolved in nitric acid, filtered through a microfilter to remove insoluble impurities, and then diluted and brought to volume with deionized water to obtain the sample solution to be tested.

[0081] Next, the test sample solution was quantitatively added to the test solution to obtain the reaction solution, and the fluorescence intensity of the reaction solution was tested.

[0082] In one embodiment, step S30 further includes:

[0083] Five gas generators with the same formula but produced by two different mixing processes were provided. Twenty solid samples were then randomly sampled twice from different parts of each generator. A certain mass of the solid sample was weighed, thoroughly ground, dissolved in nitric acid, filtered through a microfilter to remove insoluble impurities, and diluted and brought to volume with deionized water to obtain the test sample solution.

[0084] Add the above-mentioned sample solution to the test solution, mix well, and use a fluorescence spectrophotometer to test its emission spectrum. Measure the fluorescence emission intensity of the sample solution at 490 nm for different amounts of sample solution added. Characterize the distribution of copper element by the trend of fluorescence spectrum changes, and characterize the uniformity of mixing of each component material in the gas generator.

[0085] S40, based on the standard curve and the fluorescence intensity of the reaction solution, quantitatively analyze the concentration of copper ions in the sample solution to be tested.

[0086] Specifically, step S40 also includes:

[0087] The concentration of copper ions in the sample solution is determined based on the standard curve of copper ions. If the concentration of copper ions in the sample solution is too high, it needs to be diluted with deionized water to the range of copper ion concentration applicable to the standard curve.

[0088] Preferably, the process after step S40 further includes:

[0089] The copper content in the sample solution was accurately determined using a standard curve and compared with the reagent formulation.

[0090] The present invention will now be further described with reference to specific embodiments.

[0091] Example 1:

[0092] This embodiment 1 provides a method for detecting the copper oxide content in a gas generator using a chemical sensor, the specific steps of which include the following:

[0093] Step (1) Preparation of coumarin compounds containing phenylhydrazone groups (I): Under a nitrogen atmosphere, the aldehyde compound of coumarin (322 mg, 1.2 mmol) and 4-methoxyphenylhydrazine (345 mg, 2.5 mmol) were dissolved in 10 mL of anhydrous ethanol, and then... o The reaction was heated under reflux at C for 7 hours. After the reaction was complete, it was allowed to cool naturally to room temperature. The solvent ethanol was removed by vacuum distillation to obtain the crude product. The crude product was purified by silica gel column chromatography using a mixed solution of dichloromethane / ethyl acetate / methanol in a volume ratio of 35 / 5 / 1 as the eluent, and then dried in a vacuum drying oven to obtain the target compound (I).

[0094] The structural characterization results of the target compound (I) by 1H NMR are as follows:

[0095] 1 H NMR (500MHz, CDCl3): 7.48-7.51 (1H, t), 7.23-7.24 (1H, m), 7.01 (s, 2H), 6.84-6.88 (d, 1H), 6.53 (2H, s), 6.36 (1H, s), 3.42 (3H, s), 2.90-2.97 (4H,q), 2.19-2.23 (4H, t), 2.00-2.03 (4H, t);

[0096] 13 C NMR (125MHz, CDCl3): 156.1, 140.1, 138.0, 133.1, 132.1, 129.9, 129.5, 124.4, 120.2, 115.1, 112.1, 45.4, 42.4, 41.9, 36.5, 28.0;

[0097] MS(ESI), m / z (rel. / Cal.): [M+H] + 389.8 / 390.2.

[0098] Step (2) Preparation of test solution: Prepare HEPES buffer solution with a concentration of 10 mM and a pH of 7.1; prepare THF solution of compound (I) to obtain a concentration of 1 × 10⁻⁶. -4 The first solution was prepared at a concentration of 1 mol / L. 1 mL of this first solution was placed in a 10 mL colorimetric tube and diluted to volume with 9 mL of HEPES buffer solution to obtain a concentration of 1 × 10⁻⁶ mol / L. -5 A mol / L test solution (THF to HEPES buffer solution volume ratio 1:9).

[0099] Step (3) Preparation of copper ion standard solution: Prepare a 3.0×10⁻⁶ copper ion standard solution using deionized water. -3 A mol / L aqueous solution of Cu(NO3)2.

[0100] Step (4) Plot the standard curve of copper ion concentration and fluorescence intensity: Take 3 mL of the test solution prepared in step (2) and place it in a quartz cuvette. Under room temperature conditions, the excitation wavelength is 410 nm, and its emission spectrum is measured using a fluorescence spectrophotometer. Then, add the Cu(NO3)2 aqueous solution prepared in step (2) in the following order (unit: μL): 0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 3.0, 5.0 and 5.0 (the effect on the total volume is negligible). Continuously test the fluorescence spectrum under the same conditions.

[0101] Please see Figure 2 , Figure 2 The above is a fluorescence titration diagram of the test solution provided in Example 1 of this invention for different concentrations of copper ions; Figure 2 The titration curves at 490 nm, from bottom to top, represent the copper ion concentrations in the system (unit: 10). -5 The fluorescence spectra of the system at concentrations of mol / L were 0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.5, 3.0 and 3.5, respectively.

[0102] from Figure 2 As can be seen, the fluorescence emission intensity gradually increases with increasing copper ion concentration, and the maximum emission peak shifts from 520 nm to 490 nm. Furthermore, when the copper ion concentration in the system is only 2 × 10⁻⁶, the fluorescence emission intensity increases. -6 At a concentration of mol / L, the fluorescence intensity showed a very significant change compared to the blank solution; when the copper ion concentration increased to 3.5 × 10⁻⁶, the fluorescence intensity also showed a significant change. -5 At mol / L, the fluorescence intensity reached its peak, with the fluorescence intensity at 490 nm increasing by 470 times, and the fluorescence quantum yield of the solution increasing from 0.05 to 0.67.

[0103] Please see Figure 3 , Figure 3 The linear relationship between the fluorescence intensity change at 490 nm and the copper ion concentration of the test solution provided in Example 1 of this invention; Figure 3 It can be seen that within the concentration range of 0–35 μM, the change in fluorescence spectrum exhibits a good linear relationship with copper ions (R0). 2 =0.9986). The linear equation obtained from the simulation is y = -0.38852 + 134.5417*x (y represents the fluorescence intensity at 490 nm, and x represents the concentration of copper ions in units of 10).-5 (mol / L), indicating that the detection method provided by this invention can achieve accurate quantitative analysis of copper ions. According to the formula: Detection limit = The detection limit of this complex was calculated to be as low as 150 nM. The standard deviation of the fluorescence intensity of the blank solution is represented by ten measurements, where k represents... Figure 3 The slope of the fitted curve. It can be seen that the target compound (I) of Example 1 of this invention can achieve highly sensitive detection of copper ions.

[0104] Step (5) Repeat the preparation of test solutions: Prepare a 10 mM HEPES buffer solution with a pH of 7.1; prepare a THF solution of compound (I) to obtain a concentration of 1 × 10⁻⁶. -4 The first solution was prepared at a concentration of 1 mol / L. 1 mL of this first solution was placed in a 10 mL colorimetric tube and diluted to volume with 9 mL of HEPES buffer solution to obtain a concentration of 1 × 10⁻⁶ mol / L. -5 A mol / L test solution (THF to HEPES buffer solution volume ratio 1:9).

[0105] Step (6) Prepare aqueous solutions of different cations: Prepare deionized water solutions of NaNO3, KNO3, LiCl, AgNO3, MgSO4, MnSO4·2H2O, Zn(NO3)2·6H2O, Ni(NO3)2·6H2O, Pb(NO3)2, Ba(NO3)2, Ca(NO3)2·4H2O, CoCl2·6H2O, CdSO4·8H2O, Fe(NO3)3·9H2O, Al(NO3)3·9H2O, and Cr(NO3)3·9H2O. The cation concentration of each of the above deionized water solutions is 1×10⁻⁶. -2 mol / L.

[0106] Step (7) Selectivity experiment for copper ions: Take 3 mL of the test solution prepared in step (5) and place it in a quartz cuvette; then, add 30 μL of aqueous solutions of each different cation prepared in step (6) to the test solution; under room temperature conditions, excite at a wavelength of 410 nm and measure its emission spectrum using a fluorescence spectrophotometer. Then continue to add copper ion solution with a concentration of 3.0 × 10⁻⁶. -5 The concentration was mol / L, the excitation wavelength was 410 nm, and the emission spectrum was measured using a fluorescence spectrophotometer.

[0107] Please see Figure 4 , Figure 4 This is a graph showing the recognition response of the test solution provided in Example 1 of the present invention to copper ions in the presence of common interfering ions; where the vertical axis represents the fluorescence intensity at 490 nm, and the horizontal axis represents the concentration at 10 × 10⁻⁶. -5Aqueous solutions of various cations at mol / L (interfering ions), and aqueous solutions of various cations with added copper ions (interfering ions plus copper ions). Comparison. Figure 4 As can be seen from the height of the bar chart, the fluorescence spectral response of compound (I) in Example 1 of this invention to other common metal ions is much smaller than its response to copper ions. Moreover, even under conditions of coexisting interfering ions, compound (I) still exhibits a good response to copper ions. The error bars represent the standard deviation of three measurements, indicating that Example 1 of this invention can achieve highly selective detection of copper ions.

[0108] Step (8) Repeat the preparation of test solutions: Prepare a 10 mM HEPES buffer solution with a pH of 7.1; prepare a THF solution of compound (I) to obtain a concentration of 1 × 10⁻⁶. -4 The first solution was prepared at a concentration of 1 mol / L. 1 mL of this first solution was placed in a 10 mL colorimetric tube and diluted to volume with 9 mL of HEPES buffer solution to obtain a concentration of 1 × 10⁻⁶ mol / L. -5 A mol / L test solution (THF to HEPES buffer solution volume ratio 1:9).

[0109] Step (9) Preparation of the test sample solution: Five batches of materials in the same state were continuously produced using both traditional mechanical mixing and pneumatic mixing processes, according to the same gas generator formula. Two parallel samples were taken from each batch. A total of 20 solid samples were obtained, each with a mass of 100 mg. After thoroughly grinding the solid samples, they were dissolved in 10 mL of nitric acid, filtered through a microfilter to remove insoluble impurities, and diluted 10 times with deionized water to obtain the test sample solution (gas generator test sample).

[0110] Step (10) Test the fluorescence emission spectrum of the sample solution to be tested: Take 200 μL of each batch of sample solution to be tested and add them to 10 mL of test solution. Shake well and measure their fluorescence emission spectrum.

[0111] Please see Figure 5 , Figure 5 This is a graph showing the fluorescence spectrum changes of test sample solutions prepared by adding gas generators produced by different mixing processes to the test solution provided in Example 1 of the present invention; wherein, as shown in Example 1... Figure 5 As shown, the fluorescence intensity of the 10 test sample solutions of the gas generator produced using the pneumatic mixing process showed a smaller trend, indicating less fluctuation in the copper element distribution, meaning that the components of this reagent had good mixing uniformity and composite effect. In contrast, the fluorescence intensity of the gas generator column produced using the mechanical mixing process showed a larger change, indicating greater fluctuation in the copper element distribution, meaning that the mixing uniformity and product consistency of this process were poor.

[0112] Please see Figure 6, Figure 6 The fluorescence emission spectrum of the test sample solution after adding a gas generator produced by a pneumatic mixing process to the test solution provided in Example 1 of the present invention. Wherein, as... Figure 6 As shown, the fluorescence intensity of 10 sample solutions produced by the pneumatic mixing process was tested. The average value of the fluorescence intensity change was 185, corresponding to a copper ion concentration of 1.42 × 10⁻⁶ in the standard curve. -5 The calculated copper oxide content was 5.6 mg / L, which is consistent with the 5.5% copper oxide content added in the formula, indicating that this method can accurately determine the copper oxide content in the gas generator sample.

[0113] This invention discloses a method for detecting copper oxide in a gas generator using a chemical sensor, comprising the following steps: First, a compound containing a phenylhydrazone group can undergo a hydrolysis reaction under the catalysis of copper ions to generate a corresponding carbonyl compound, causing the solution to change from almost no fluorescence to a strong green fluorescence, thereby enabling the specific identification and detection of copper ions.

[0114] The compound described in this invention, when used as a fluorescence sensor for the detection of copper ions in aqueous solution, exhibits a significant fluorescence enhancement response, high detection sensitivity, and a detection limit as low as 150 nM. Using a standard curve, the precise content and distribution of copper oxide in the gas generator can be accurately determined, thereby evaluating the quality of the mixing process. It has extremely high selectivity for copper ions, with almost no interference from other common metal ions.

[0115] Therefore, the detection method provided by this invention can conveniently and quickly detect the precise content of copper oxide in a gas generator, and characterize the trend of copper oxide content change in different parts of the agent by the fluctuation of fluorescence intensity, thereby judging the influence of different mixing processes on the uniformity of material mixing, providing a convenient, fast and reliable evaluation method for the selection of mixing processes and the setting of mixing process parameters in actual industrial production.

[0116] In summary, the method for detecting copper oxide in a gas generator using a chemical sensor provided by this invention can achieve highly sensitive and selective detection of copper ions. In particular, it can determine the content and distribution of copper oxide in the gas generator, and thereby evaluate the uniformity of the reagent mixing process and the composite effect of each component of the reagent. This provides a convenient, fast and reliable evaluation method for the selection of mixing processes and the setting of mixing process parameters in actual industrial production.

[0117] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for detecting the content of cupric oxide in a gas generating agent using a chemical sensor, characterized by, The application relates to a method for quantitatively analyzing the concentration of copper ions in a sample solution, comprising the following steps: S10, gradually adding copper ion standard solutions with different volumes into a test solution, and testing the fluorescence intensity of the mixed solution after each drop is completed; The test solution comprises a coumarin compound containing a phenylhydrazone group; S20, drawing a standard curve according to the relationship between the copper ion concentration and the fluorescence intensity change value; S30, adding a sample solution to be tested into the test solution to obtain a reaction solution, and testing the fluorescence intensity of the reaction solution; the sample solution to be tested is prepared by dissolving, diluting and constant-volume processing of a gas generating agent containing cupric oxide; S40, quantitatively analyzing the concentration of copper ions in the sample solution to be tested according to the standard curve and the fluorescence intensity of the reaction solution; The preparation method of the test solution in the S10 step comprises the following steps: mixing a coumarin compound containing an aldehyde group, 4-methoxyphenylhydrazine and anhydrous ethanol, and then performing an anaerobic heating reflux reaction; the molar ratio of the coumarin compound containing an aldehyde group to 4-methoxyphenylhydrazine is 1: (1.2-2.5); the dosage ratio of the coumarin compound containing an aldehyde group to anhydrous ethanol is 1g: (30-100) mL; After the anaerobic heating reflux reaction is completed, the crude product is obtained by naturally cooling to room temperature and removing anhydrous ethanol through reduced-pressure distillation; The crude product is subjected to column chromatography separation and purification treatment to obtain the coumarin compound containing a phenylhydrazone group; mixing the benzhydryl group-containing coumarin compound, an organic solvent and a buffer to obtain the test solution; the concentration of the benzhydryl group-containing coumarin compound in the test solution is 5×10 -7 -1×10 -5 mol / L; the volume ratio of the buffer to the organic solvent is (1-50):5, and the pH value of the buffer is 5.5-10; the benzhydryl group-containing coumarin compound comprises a structure as shown in structural formula (I): (I)。 2. The method for detecting the content of copper oxide in a gas generating agent using a chemical sensor according to claim 1, characterized by, In the anaerobic heating reflux reaction, the reaction atmosphere is an inert atmosphere, the reflux reaction temperature is 80-90 DEG C, and the reflux reaction time is 6-7h.

3. The method of claim 1, wherein the chemical sensor is a copper sensor. The organic solvent comprises any one of dimethyl sulfoxide, acetonitrile, tetrahydrofuran, N, N-dimethylformamide and acetone, and the buffer solution comprises 4-hydroxyethylpiperazine ethanesulfonic acid.

4. The method of claim 1, wherein the chemical sensor is a copper sensor. In the S20 step, the fluorescence intensity change value corresponding to the copper ion concentration at 490nm is taken as the ordinate, the copper ion concentration is taken as the abscissa, and linear fitting is performed to obtain the standard curve.

5. The method for detecting the content of copper oxide in a gas generating agent using a chemical sensor according to claim 1, characterized by, The S30 step further comprises the following steps: random sampling and sufficient grinding are performed on the same batch of gas generating agent propellant columns to obtain a propellant solid sample; the propellant solid sample is dissolved in nitric acid, the insoluble impurities are removed through filtration with a micro filter, and then dilution and constant-volume processing are sequentially performed with deionized water to obtain the sample solution to be tested; the fluorescence emission spectrum of the reaction solution is sequentially tested, the distribution of copper elements is characterized through the change trend of the fluorescence emission spectrum, and finally the uniformity of the mixture of various component materials in the gas generating agent is evaluated.

6. The method of claim 5, wherein the chemical sensor is a copper sensor. After the S40 step, the following steps are further included: the content of copper elements in the sample solution to be tested is accurately determined by using the standard curve, and compared with the propellant formula.

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