Method for detecting residual dibutyl tin diacetate in a silicone adhesive

Abstract

The present application relates to a kind of detection methods for residual amount of dibutyl tin diacetate in silica gel adhesive, comprising the following steps: S1, instrument preparation: ICP-MS;S2, preparation of test solution, according to GB / T16886.18-2022, different solvents are selected as leaching solvent, and parallel sample is prepared by adding strict leaching, and corresponding solvent is used as blank, the leaching solution is placed in microwave digestion tank, the solvent is evaporated to dryness, nitric acid is added, and the program is digested, after digestion, it is evaporated to nearly dry, and it is constant volume with nitric acid, and the same method is used to prepare blank control solution without sample, the present application uses microwave digestion pretreatment mode, which can effectively decompose the complex matrix of silica gel adhesive and improve the release efficiency of organotin;The tin element is detected by ICP-MS, which has the advantages of high sensitivity and low detection limit;Through element content conversion, quantitative analysis of dibutyl tin diacetate is realized, and the matrix interference problem caused by direct detection of organotin is avoided;The method has good repeatability, and is suitable for daily quality control and detection analysis of silica gel adhesive product.

Description

Technical Field

[0001] This invention relates to the field of silicone adhesive testing, specifically a method for detecting the residual amount of dibutyltin diacetate in silicone adhesives. Background Technology

[0002] Dibutyltin diacetate is a commonly used organotin catalyst, widely applied in the crosslinking and curing processes of silicone adhesives and silicone rubber materials. This type of catalyst effectively promotes the condensation reaction of siloxane systems, improving the curing efficiency and adhesive properties of the products.

[0003] However, improper control of the residual content of dibutyltin diacetate in silicone adhesives may adversely affect the material's environmental friendliness, biosafety, and long-term stability. This is particularly true in applications such as electronics, electrical engineering, and medical devices, where higher requirements are placed on the detection and control of organotin residue content.

[0004] In existing technologies, the detection of organotin compounds mostly employs chromatographic or elemental analysis methods. However, the complex matrix of silicone adhesives presents challenges for direct detection of organotin compounds, including difficulties in pretreatment, significant matrix interference, and insufficient detection stability, making accurate and reliable quantitative analysis difficult. Therefore, it is necessary to provide a method for the detection of dibutyltin diacetate that is suitable for silicone adhesive systems and provides stable and reproducible results. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art, adapt to practical needs, and provide a method for detecting the residual amount of dibutyltin diacetate in silicone adhesives. This solves the technical problem that in the current prior art, the detection of organotin compounds mostly adopts chromatographic or elemental analysis methods, but the silicone adhesive matrix is ​​complex, and direct detection of organotin compounds has problems such as difficult pretreatment, large matrix interference, and insufficient detection stability, making it difficult to achieve accurate and reliable quantitative analysis.

[0006] To achieve the objective of this invention, the technical solution adopted is as follows: A method for detecting the residual amount of dibutyltin diacetate in silicone adhesives is designed, comprising the following steps:

[0007] S1. Instrument preparation: ICP-MS;

[0008] S2. Preparation of the test solution

[0009] According to GB / T16886.18-2022, different solvents were selected as extraction solvents, and parallel samples were prepared by strict extraction. The corresponding solvent was used as a blank. The extract was placed in a microwave digestion vessel, the solvent was evaporated to dryness, nitric acid was added, and digestion was carried out according to the program. After digestion, the solution was evaporated to near dryness and diluted with nitric acid. Blank control solution was prepared by the same method without adding sample.

[0010] S3. Preparation of the method validation solution

[0011] Dibutyltin diacetate standard stock solution: Accurately weigh a certain amount of dibutyltin diacetate standard, dissolve it in ethanol, and prepare a standard stock solution;

[0012] Dibutyltin diacetate standard solution: Accurately transfer an appropriate amount of the above dibutyltin diacetate standard stock solution, dilute with ethanol to prepare a standard solution;

[0013] Linear solution: Take a standard solution of tin in water, dilute it with nitric acid solution, and prepare standard curve solutions with different concentration gradients;

[0014] Accuracy solution: Dibutyltin diacetate standard solutions of different mass concentrations were measured and placed in microwave digestion vessels. After evaporating to remove the solvent, nitric acid was added to each digestion vessel and digestion was carried out according to the digestion procedure. After digestion, the acid solution was evaporated to near dryness, the residue was transferred with nitric acid solution, and the volume was adjusted to obtain the accuracy solution.

[0015] Repeatability solution: Prepare the solution according to the preparation method of medium concentration accuracy solution, and prepare multiple parallel samples;

[0016] Detection limit solution: Take a certain amount of dibutyltin diacetate standard solution, place it in a microwave digestion vessel, and process it according to the same procedure as the accuracy solution to obtain the detection limit solution;

[0017] Limit of Quantitation Solution: Take a standard solution of dibutyltin diacetate, place it in a microwave digestion vessel, and process it according to the same procedure as the accuracy solution to obtain the limit of quantitation solution;

[0018] S4. The detection method was validated using ICP-MS.

[0019] S5. The content of dibutyltin diacetate in the silicone adhesive was determined by ICP-MS.

[0020] Preferably, the instrument preparation in S1 involves adjusting various parameters to the working state and using ICP-MS for detection. The plasma parameters are: plasma mode; HMI; RF power 1600W; sampling depth 10.0mm; peristaltic pump speed 0.10rps; atomization chamber temperature 2℃; plasma gas 15.0L / min.

[0021] Preferably, the lens parameters in S1 are -40V at the collision cell inlet and -60V at the collision cell outlet, and the collision cell parameters are a helium flow rate of 5.0mL / min and an energy discrimination of 5.0V.

[0022] Preferably, the measurement parameters in S1 are a resolution of 0.65~0.80 μm, a measurement point / peak of 3, a repetition count of 3, and a measurement mode of He mode.

[0023] Preferably, the extraction solvent in S2 is physiological saline, ethanol, and n-hexane.

[0024] Preferably, in the S2 extraction process, the sample weighing amount is about 1.6g, the extraction solvent added amount is 8mL, the extraction ratio is 0.2g / mL, the extraction temperature is 37±1℃, and the extraction is carried out under shaking conditions.

[0025] Preferably, in the preparation of the test solution in S2, the extract is placed in a microwave digestion vessel, the solvent is evaporated at 140°C, 5 mL of nitric acid is added for digestion, and after digestion, it is evaporated to near dryness and then diluted to 10 mL with 2% nitric acid solution.

[0026] Preferably, the mass concentration of the dibutyltin diacetate standard stock solution in S3 is 1.7990 mg / mL, the mass concentration of the dibutyltin diacetate standard solution is 17.990 μg / mL, and the standard curve solution is prepared using tin element standard solution with concentration gradients including 0 μg / L, 10 μg / L, 20 μg / L, 50 μg / L, 100 μg / L and 200 μg / L, respectively denoted as STD-1, STD-2, STD-3, STD-4, STD-5 and STD-6.

[0027] Preferably, the concentration levels of the accuracy solution in S3 are 122.332 μg / L, 296.835 μg / L, and 989.450 μg / L, respectively. Three parallel samples are prepared for each concentration level. The repeatability solution is prepared according to the method for preparing medium-concentration accuracy solutions, and six parallel samples are prepared. The concentration of dibutyltin diacetate corresponding to the detection limit solution is 30.583 μg / L, and the concentration of dibutyltin diacetate corresponding to the quantitation limit solution is 61.166 μg / L.

[0028] Preferably, the method validation items in S4 include limit of detection, limit of quantitation, linearity and range, repeatability, and accuracy. Inductively coupled plasma mass spectrometry (ICP-MS) is used to detect tin in the standard working solution and the test solution, the mass spectrometry response signal of tin is recorded, the content of tin in the test solution is calculated according to the tin standard curve, and the content of dibutyltin diacetate in the silicone adhesive is calculated based on the theoretical mass fraction of tin in dibutyltin diacetate.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. The present invention employs a microwave digestion pretreatment method, which can effectively decompose the complex matrix of silicone adhesive and improve the release efficiency of organotin.

[0031] 2. This invention uses ICP-MS to detect tin, which has the advantages of high sensitivity and low detection limit.

[0032] 3. This invention achieves quantitative analysis of dibutyltin diacetate by converting elemental content, thus avoiding matrix interference problems caused by direct detection of organotin compounds.

[0033] 4. The method of the present invention has good repeatability and is suitable for daily quality control and testing analysis of silicone adhesive products. Attached Figure Description

[0034] Figure 1 This is the Sn standard curve spectrum of the present invention. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0036] A method for detecting the residual amount of dibutyltin diacetate in silicone adhesives, see [link to relevant documentation]. Figure 1 This includes the following steps:

[0037] S1. Instrument preparation: ICP-MS;

[0038] S2. Preparation of the test solution

[0039] According to GB / T16886.18-2022, different solvents were selected as extraction solvents, and parallel samples were prepared by strict extraction. The corresponding solvent was used as a blank. The extract was placed in a microwave digestion vessel, the solvent was evaporated to dryness, nitric acid was added, and digestion was carried out according to the program. After digestion, the solution was evaporated to near dryness and diluted with nitric acid. Blank control solution was prepared by the same method without adding sample.

[0040] S3. Preparation of the method validation solution

[0041] Dibutyltin diacetate standard stock solution: Accurately weigh a certain amount of dibutyltin diacetate standard, dissolve it in ethanol, and prepare a standard stock solution;

[0042] Dibutyltin diacetate standard solution: Accurately transfer an appropriate amount of the above dibutyltin diacetate standard stock solution, dilute with ethanol to prepare a standard solution;

[0043] Linear solution: Take a standard solution of tin in water, dilute it with nitric acid solution, and prepare standard curve solutions with different concentration gradients;

[0044] Accuracy solution: Dibutyltin diacetate standard solutions of different mass concentrations were measured and placed in microwave digestion vessels. After evaporating to remove the solvent, nitric acid was added to each digestion vessel and digestion was carried out according to the digestion procedure. After digestion, the acid solution was evaporated to near dryness, the residue was transferred with nitric acid solution, and the volume was adjusted to obtain the accuracy solution.

[0045] Repeatability solution: Prepare the solution according to the preparation method of medium concentration accuracy solution, and prepare multiple parallel samples;

[0046] Detection limit solution: Take a certain amount of dibutyltin diacetate standard solution, place it in a microwave digestion vessel, and process it according to the same procedure as the accuracy solution to obtain the detection limit solution;

[0047] Limit of Quantitation Solution: Take a standard solution of dibutyltin diacetate, place it in a microwave digestion vessel, and process it according to the same procedure as the accuracy solution to obtain the limit of quantitation solution;

[0048] S4. The detection method was validated using ICP-MS.

[0049] S5. The content of dibutyltin diacetate in the silicone adhesive was determined by ICP-MS.

[0050] For details, see Figure 1 In S1, the instrument preparation involves adjusting various parameters to the working state and using ICP-MS for detection. The plasma parameters are as follows: plasma mode; HMI; RF power 1600W; sampling depth 10.0mm; peristaltic pump speed 0.10rps; atomization chamber temperature 2℃; plasma gas 15.0L / min.

[0051] For more details, see Figure 1 In S1, the lens parameters are -40V at the collision cell inlet and -60V at the collision cell outlet. The collision cell parameters are helium flow rate of 5.0mL / min and energy discrimination of 5.0V.

[0052] Further, see Figure 1 In S1, the measurement parameters are a resolution of 0.65~0.80 μm, a measurement point / peak of 3, a repetition count of 3, and a measurement mode of He mode.

[0053] Further, see Figure 1 The extraction solvents in S2 are physiological saline, ethanol and n-hexane.

[0054] It is worth noting that, see Figure 1 During the extraction process in S2, the sample weighing amount was approximately 1.6g, the extraction solvent added amount was 8mL, the extraction ratio was 0.2g / mL, the extraction temperature was 37±1℃, and the extraction was carried out under shaking conditions.

[0055] It is worth noting that, see Figure 1 In the preparation of the test solution in S2, the extract was placed in a microwave digestion vessel, the solvent was evaporated at 140°C, and 5 mL of nitric acid was added for digestion. After digestion, the solution was evaporated to near dryness and then diluted to 10 mL with 2% nitric acid solution.

[0056] It is worth mentioning that, see Figure 1 The mass concentration of the dibutyltin diacetate standard stock solution in S3 is 1.7990 mg / mL, and the mass concentration of the dibutyltin diacetate standard solution is 17.990 μg / mL. The standard curve solutions are prepared using tin element standard solutions, with concentration gradients including 0 μg / L, 10 μg / L, 20 μg / L, 50 μg / L, 100 μg / L, and 200 μg / L, which are denoted as STD-1, STD-2, STD-3, STD-4, STD-5, and STD-6, respectively.

[0057] It is worth noting that, see Figure 1 The accuracy solution concentration levels in S3 were 122.332 μg / L, 296.835 μg / L, and 989.450 μg / L, respectively. Three parallel samples were prepared for each concentration level. The repeatability solution was prepared according to the method for preparing medium-concentration accuracy solutions, and six parallel samples were prepared. The concentration of dibutyltin diacetate corresponding to the detection limit solution was 30.583 μg / L, and the concentration of dibutyltin diacetate corresponding to the quantitation limit solution was 61.166 μg / L.

[0058] It is worth emphasizing that, see Figure 1 The method validation items in S4 include limit of detection, limit of quantitation, linearity and range, repeatability, and accuracy. Inductively coupled plasma mass spectrometry (ICP-MS) is used to detect tin in the standard working solution and the test solution. The mass spectrometry response signal of tin is recorded. The content of tin in the test solution is calculated according to the tin standard curve. Based on the theoretical mass fraction of tin in dibutyltin diacetate, the content of dibutyltin diacetate in the silicone adhesive is calculated.

[0059] Example 1

[0060] Instruments and reagents

[0061] ICP-MS (7850, Agilent Technologies), electronic balance (XSR105DU / A, accuracy 0.00001g, METTLER), microwave digester (M6, Shanghai Yiyao Instrument Technology Development Co., Ltd.).

[0062] Tin standard solution in water (100 mg / L, Tanmo Quality Inspection Technology Co., Ltd.), indium standard solution in water (1000 mg / L, Tanmo Quality Inspection Technology Co., Ltd.), dibutyltin diacetate standard material (98%, Stanford Chemical Reagent Company), ethanol (chromatographic grade, PorMee), n-hexane (chromatographic grade, PorMee), nitric acid (UP grade, Chongqing Chuandong Chemical (Group) Co., Ltd.), physiological saline (Guizhou Kelun Pharmaceutical Co., Ltd.).

[0063] Instrument conditions

[0064] The ICP-MS instrument parameter settings are shown in Table 1.

[0065] Table 1. ICP-MS Testing Instrument Requirements

[0066]

[0067] Solution preparation

[0068] Preparation of the test solution: According to GB / T16886.18-2022, physiological saline, ethanol, and n-hexane were selected as three different solvents for extraction. Approximately 1.6 g of sample was weighed and 8 mL of extraction solvent (extraction ratio 0.2 g / mL) was added. Extraction was performed at (37±1)℃ with shaking to prepare parallel samples, with the corresponding solvent used as a blank. 5 mL of the extract was placed in a microwave digestion vessel, and the solvent was evaporated to dryness at 140℃. Then, 5 mL of nitric acid was added, and digestion was performed according to the program. After digestion, the solution was evaporated to near dryness and then diluted to 10 mL with 2% nitric acid. A blank control solution was prepared using the same method without adding the sample.

[0069] Preparation of the method validation solution: Dibutyltin diacetate standard stock solution: Accurately weigh a certain amount of dibutyltin diacetate standard, dissolve it in ethanol, and prepare a standard stock solution with a mass concentration of 1.7990 mg / mL.

[0070] Dibutyltin diacetate standard solution: Accurately transfer an appropriate amount of the above dibutyltin diacetate standard stock solution and dilute it with ethanol to prepare a standard solution with a mass concentration of 17.990 μg / mL.

[0071] Linear solutions: Take a standard solution of tin in water, dilute it with 2% (volume fraction) nitric acid solution, and prepare standard curve solutions with five different concentration gradients (excluding zero point). The specific contents of each element in the linear solutions are 0 μg / L, 10 μg / L, 20 μg / L, 50 μg / L, 100 μg / L, and 200 μg / L, respectively denoted as STD-1, STD-2, STD-3, STD-4, STD-5, and STD-6.

[0072] Accuracy solutions: 5 mL each of dibutyltin diacetate standard solutions with mass concentrations of 122.332 μg / L, 296.835 μg / L, and 989.450 μg / L were measured and placed in microwave digestion vessels. After evaporating to remove the solvent at 140 °C, 5 mL of nitric acid was added to each digestion vessel, and digestion was carried out according to the digestion procedure shown in Table 5. After digestion, the acid solution was evaporated to near dryness at 140 °C, the residue was transferred with 2% (volume fraction) nitric acid solution, and the volume was adjusted to 10 mL to obtain the accuracy solutions. Three parallel samples were prepared for each concentration level.

[0073] Repeatability solution: Prepare the solution according to the method for preparing medium concentration accuracy solution, and prepare 6 parallel samples.

[0074] Detection limit solution: Take 5 mL of dibutyltin diacetate standard solution with a concentration of 30.583 μg / L, place it in a microwave digestion vessel, and process it according to the same procedure as the accuracy solution to obtain the detection limit solution.

[0075] Limit of Quantification Solution: Take 5 mL of dibutyltin diacetate standard solution with a concentration of 61.166 μg / L, place it in a microwave digestion vessel, and process it according to the same procedure as the accuracy solution to obtain the limit of quantification solution for dibutyltin diacetate.

[0076] The method validation results for a method of detecting dibutyltin diacetate residue in a silicone adhesive are as follows:

[0077] linear

[0078] The linear solution was tested according to the conditions in Table 1. A standard curve was plotted with concentration on the x-axis and response value on the y-axis. The linear correlation coefficient r should be ≥0.99. The test results are shown in Table 2. As can be seen from the results in Table 2, this method has good linearity.

[0079] Table 2 Linear Results

[0080]

[0081] Limit of detection (LOD) and limit of quantitation (LOQ)

[0082] One portion of LOD solution and one portion of LOQ solution were each injected three times for testing. The specific test results for the limits of detection and quantitation are shown in Table 3.

[0083] Table 3 LOD and LOQ Results

[0084]

[0085] Repeatable results

[0086] Take a repeatable solution and test it according to the instrument conditions shown in Table 1. The results are shown in Table 4. According to GB / T27417-2017, the RSD should be ≤15%. As can be seen from the results in Table 2, this method has good repeatability.

[0087] Table 4 Repeatability Results

[0088]

[0089] Accuracy

[0090] Nine accuracy solutions (low, medium, and high concentrations) were taken and tested according to the conditions in Table 1. According to GB / T27417-2017, the acceptable recovery rate of the target analyte in the solution is 60%–120% for low and high concentrations, and 80%–110% for high concentrations. The results are shown in Table 5. The results in the table indicate that this method has good accuracy.

[0091] Table 5 Accuracy Results

[0092]

[0093] Summary of method validation results

[0094] The validation results of the Sn method are summarized in Table 6. As can be seen from the results in Table 6, the validation results of each indicator meet the requirements of the evaluation criteria.

[0095] Table 6 Summary of Method Validation Results

[0096]

[0097] Dibutyltin diacetate content test

[0098] A standard solution of tin in water was diluted with 2% (volume fraction) nitric acid solution to prepare standard curve solutions with five different concentration gradients (excluding the zero point). The tin content in the test solution was determined using inductively coupled plasma mass spectrometry (ICP-MS) under the instrument conditions shown in Table 1. The measured tin content was then converted to the dibutyltin diacetate content using the following formula. The detection results are shown in Table 7.

[0099]

[0100] In formula (1):

[0101] W — The residual amount of dibutyltin diacetate in the sample, in μg / g;

[0102] c — the concentration of tin in the test solution, in μg / L;

[0103] V—Volume of sample extract, in mL;

[0104] f—Dilution factor;

[0105] m — the sample mass used to prepare the extract, in grams;

[0106] 351.03 — Molecular weight of dibutyltin diacetate;

[0107] 118.71 — the relative atomic mass of tin;

[0108] 1000 – Unit conversion factor.

[0109] Table 7 Residual amounts of dibutyltin diacetate

[0110]

[0111] In addition, all components designed in this invention are general standard parts or components known to those skilled in the art. Their structure and principle can be known to those skilled in the art through technical manuals or conventional experimental methods. Those skilled in the art can fully implement them, so there is no need to elaborate. The content protected by this invention does not involve improvements to the internal structure and method.

Claims

1. A method for detecting the residual amount of dibutyltin diacetate in silicone adhesives, characterized in that, Includes the following steps: S1. Instrument preparation: ICP-MS; S2. Preparation of the test solution According to GB / T16886.18-2022, different solvents were selected as extraction solvents, and parallel samples were prepared by strict extraction. The corresponding solvent was used as a blank. The extract was placed in a microwave digestion vessel, the solvent was evaporated to dryness, nitric acid was added, and digestion was carried out according to the program. After digestion, the solution was evaporated to near dryness and diluted with nitric acid. Blank control solution was prepared by the same method without adding sample. S3. Preparation of the method validation solution Dibutyltin diacetate standard stock solution: Accurately weigh a certain amount of dibutyltin diacetate standard, dissolve it in ethanol, and prepare a standard stock solution; Dibutyltin diacetate standard solution: Accurately transfer an appropriate amount of the above dibutyltin diacetate standard stock solution, dilute with ethanol to prepare a standard solution; Linear solution: Take a standard solution of tin in water, dilute it with nitric acid solution, and prepare standard curve solutions with different concentration gradients; Accuracy solution: Dibutyltin diacetate standard solutions of different mass concentrations were measured and placed in microwave digestion vessels. After evaporating to remove the solvent, nitric acid was added to each digestion vessel and digestion was carried out according to the digestion procedure. After digestion, the acid solution was evaporated to near dryness, the residue was transferred with nitric acid solution, and the volume was adjusted to obtain the accuracy solution. Repeatability solution: Prepare the solution according to the preparation method of medium concentration accuracy solution, and prepare multiple parallel samples; Detection limit solution: Take a certain amount of dibutyltin diacetate standard solution, place it in a microwave digestion vessel, and process it according to the same procedure as the accuracy solution to obtain the detection limit solution; Limit of Quantitation Solution: Take a standard solution of dibutyltin diacetate, place it in a microwave digestion vessel, and process it according to the same procedure as the accuracy solution to obtain the limit of quantitation solution; S4. The detection method was validated using ICP-MS. S5. The content of dibutyltin diacetate in the silicone adhesive was determined by ICP-MS.

2. The method for detecting the residual amount of dibutyltin diacetate in silicone adhesive as described in claim 1, characterized in that, The instrument preparation in S1 involves adjusting various parameters to the working state and using ICP-MS for detection. The plasma parameters are: plasma mode; HMI; RF power 1600W; sampling depth 10.0mm; peristaltic pump speed 0.10rps; atomization chamber temperature 2℃; plasma gas 15.0L / min.

3. The method for detecting the residual amount of dibutyltin diacetate in silicone adhesive as described in claim 1, characterized in that, The lens parameters in S1 are -40V at the collision cell inlet and -60V at the collision cell outlet. The collision cell parameters are helium flow rate of 5.0mL / min and energy discrimination of 5.0V.

4. The method for detecting the residual amount of dibutyltin diacetate in silicone adhesive as described in claim 1, characterized in that, The measurement parameters in S1 are: resolution 0.65~0.80 μm, measurement points / peaks 3, repetitions 3, measurement mode He mode.

5. The method for detecting the residual amount of dibutyltin diacetate in silicone adhesive as described in claim 1, characterized in that, The extraction solvent in S2 is physiological saline, ethanol, and n-hexane.

6. The method for detecting the residual amount of dibutyltin diacetate in silicone adhesive as described in claim 1, characterized in that, In the S2 extraction process, the sample weighing amount is approximately 1.6g, the extraction solvent added amount is 8mL, the extraction ratio is 0.2g / mL, the extraction temperature is 37±1℃, and the extraction is carried out under shaking conditions.

7. The method for detecting the residual amount of dibutyltin diacetate in silicone adhesive as described in claim 1, characterized in that, In the preparation of the test solution in S2, the extract is placed in a microwave digestion vessel, the solvent is evaporated at 140°C, and then 5 mL of nitric acid is added for digestion. After digestion, the solution is evaporated to near dryness and then diluted to 10 mL with 2% nitric acid solution.

8. The method for detecting the residual amount of dibutyltin diacetate in silicone adhesive as described in claim 1, characterized in that... The mass concentration of the dibutyltin diacetate standard stock solution in S3 is 1.7990 mg / mL, the mass concentration of the dibutyltin diacetate standard solution is 17.990 μg / mL, and the standard curve solution is prepared using tin element standard solution with concentration gradients including 0 μg / L, 10 μg / L, 20 μg / L, 50 μg / L, 100 μg / L and 200 μg / L, respectively denoted as STD-1, STD-2, STD-3, STD-4, STD-5 and STD-6.

9. The method for detecting the residual amount of dibutyltin diacetate in silicone adhesive as described in claim 1, characterized in that, The accuracy solutions in S3 have concentration levels of 122.332 μg / L, 296.835 μg / L, and 989.450 μg / L, respectively. Three parallel samples are prepared for each concentration level. The repeatability solution is prepared according to the method for preparing medium-concentration accuracy solutions, and six parallel samples are prepared. The concentration of dibutyltin diacetate corresponding to the detection limit solution is 30.583 μg / L, and the concentration of dibutyltin diacetate corresponding to the quantitation limit solution is 61.166 μg / L.

10. The method for detecting the residual amount of dibutyltin diacetate in the silicone adhesive as described in claim 1, characterized in that, The method validation items in S4 include limit of detection, limit of quantitation, linearity and range, repeatability, and accuracy. Inductively coupled plasma mass spectrometry is used to detect tin in the standard working solution and the test solution. The mass spectrometry response signal of tin is recorded. The content of tin in the test solution is calculated according to the tin standard curve. Based on the theoretical mass fraction of tin in dibutyltin diacetate, the content of dibutyltin diacetate in the silicone adhesive is calculated.

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