Method for determining peroxide content in perfluoropolyether

Abstract

The invention discloses a method for determining peroxide content in perfluoropolyether, and relates to the technical field of perfluoropolyether peroxide content determination, and the method comprises the following steps: collecting perfluoropolyether by using a balance weighing method to obtain a perfluoropolyether sample; the method comprises the following steps: pretreating a perfluoropolyether sample through a microwave-assisted extraction technology to obtain a perfluoropolyether solution after microwave extraction; adding the bifunctional probe solution into the perfluoropolyether solution, and calculating the reaction efficiency of the perfluoropolyether solution by adopting a black glass bottle under a light-free condition to obtain a perfluoropolyether reaction mixture; separating the perfluoropolyether reaction mixture by adopting a liquid chromatography-mass spectrometry separation method to obtain separated perfluoropolyether peroxide; the method comprises the following steps: ionizing perfluoropolyether peroxide by using an electrospray ionization source, and detecting characteristic ions of the perfluoropolyether peroxide by using a mass spectrometer to obtain mass spectrum information of the perfluoropolyether peroxide; the mass spectrum information is based on the perfluoropolyether peroxide.

Description

Technical Field

[0001] The invention relates to the technical field of perfluoropolyether peroxide content determination, in particular to a method for determining the peroxide content in perfluoropolyether. Background Art

[0002] Perfluoropolyether peroxide content determination is an analytical technique specifically designed to quantify the peroxide concentration in PFPE. It is designed to accurately evaluate the potentially unstable components in these high-performance lubricants and protective materials. The technology ensures the determination of peroxides in PFPE through a series of precise steps, including high-precision sample collection, efficient microwave-assisted extraction, specific bifunctional probe reaction, high-resolution liquid chromatography-mass spectrometry separation and detection, and quantitative analysis based on standard curves.

[0003] In the technical field of perfluoropolyether peroxide content determination, traditional methods rely on ordinary electronic balances for sample weighing. The balance lacks sufficient accuracy and stability, especially when operated in an open environment, and is easily affected by external factors such as air flow and temperature changes. The selection and handling of sample bottles are not strict enough, which can easily introduce impurities or pollutants. At the same time, the extraction efficiency of traditional extraction methods is low, resulting in failure to completely dissolve or extract the target compound, making the final measurement result low and unable to truly reflect the peroxide content in the sample. In addition, high-temperature extraction conditions may destroy the structure of the target compound and affect its stability and detection accuracy. Secondly, in traditional mass spectrometry detection methods, the ion source selection and detection mode settings are not optimized enough, resulting in failure to effectively ionize or detect the target compound. Summary of the invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a method for determining the peroxide content in perfluoropolyether, which solves the problem that the traditional extraction method has low extraction efficiency, resulting in failure to completely dissolve or extract the target compound, making the final measurement result low and unable to truly reflect the peroxide content in the sample. In addition, high temperature extraction conditions may destroy the structure of the target compound, affecting its stability and detection accuracy.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for determining the peroxide content in a perfluoropolyether, comprising: collecting the perfluoropolyether by a balance weighing method to obtain a perfluoropolyether sample;

[0008] The perfluoropolyether sample is pretreated by microwave-assisted extraction technology to obtain a perfluoropolyether solution after microwave extraction;

[0009] The bifunctional probe solution is added to the perfluoropolyether solution, and the reaction efficiency of the perfluoropolyether solution is calculated in a black glass bottle under light-free conditions to obtain a perfluoropolyether reaction mixture;

[0010] The perfluoropolyether reaction mixture is separated by a liquid chromatography-mass spectrometry separation method to obtain separated perfluoropolyether peroxide;

[0011] The perfluoropolyether peroxide is ionized by using an electrospray ion source, and the characteristic ions of the perfluoropolyether peroxide are detected by using a mass spectrometer to obtain mass spectrum information of the perfluoropolyether peroxide;

[0012] Based on the mass spectrum information of the perfluoropolyether peroxide, the concentration of the perfluoropolyether peroxide is calculated, and the peroxide content in the perfluoropolyether is output based on the concentration of the perfluoropolyether peroxide.

[0013] As a preferred embodiment of the method for determining the peroxide content in the perfluoropolyether of the present invention, the perfluoropolyether is collected by a balance weighing method to obtain a perfluoropolyether sample, and the specific steps are as follows:

[0014] Choose clean and dry sample bottles and high-precision electronic balance GS8202;

[0015] Place the sample bottle on the high-precision electronic balance GS8202 and open the wind shield of the high-precision electronic balance GS8202;

[0016] The perfluoropolyether in the container is taken out by using a pipette and added into a sample bottle to obtain a perfluoropolyether sample.

[0017] As a preferred embodiment of the method for determining the peroxide content in the perfluoropolyether of the present invention, the perfluoropolyether sample is pretreated by microwave-assisted extraction technology to obtain a perfluoropolyether solution after microwave extraction, and the specific steps are as follows:

[0018] A microwave transparent glass bottle was selected as a microwave-assisted extraction container, and a polar modified organic solvent methanol-water mixture was prepared;

[0019] The perfluoropolyether sample was transferred into a microwave transparent glass bottle, and a methanol-water mixture was added into the microwave transparent glass bottle;

[0020] The microwave transparent glass bottle after adding the methanol-water mixture is placed in a microwave-assisted extraction instrument for microwave-assisted extraction, and the microwave power and processing time of the microwave-assisted extraction instrument are set;

[0021] After the microwave-assisted extraction is completed, the microwave transparent glass bottle is taken out and naturally cooled to room temperature, and a perfluoropolyether solution after microwave extraction is obtained.

[0022] As a preferred embodiment of the method for determining the peroxide content in the perfluoropolyether of the present invention, the bifunctional probe solution is added to the perfluoropolyether solution after microwave extraction, and the reaction efficiency of the perfluoropolyether solution is calculated in a black glass bottle under light-free conditions to obtain a perfluoropolyether reaction mixture, and the specific steps are as follows:

[0023] A black glass bottle is selected as a reaction container, and the perfluoropolyether solution after microwave extraction is added into the black glass bottle;

[0024] The dual-function probe solution was added into the black glass bottle containing the microwave-extracted perfluoropolyether solution;

[0025] Place the black glass bottle containing the microwave-extracted perfluoropolyether solution and the dual-function probe solution in a light-free environment;

[0026] The reaction temperature and reaction time were set, and during the reaction process, the reaction kinetic function was introduced to calculate the reaction efficiency of the bifunctional probe solution and the perfluoropolyether solution after microwave extraction under different conditions. The expression is:

[0027]

[0028] Where R is the reaction efficiency, is the binding concentration of the probe solution after the reaction, H is the concentration of the bifunctional probe solution, K is the binding rate constant, T is the reaction time, t is the time constant, and exp is the exponential function during the reaction;

[0029] Setting a threshold value W of the reaction efficiency to compare with the reaction efficiency R;

[0030] When R<W, the initial concentration H of the bifunctional probe solution is gradually increased until R≥W;

[0031] When R ≥ W, it is confirmed that the binding between the bifunctional probe solution and the perfluoropolyether peroxide after microwave extraction meets the expected degree and ensures that only perfluoropolyether peroxide is detected during the reaction;

[0032] After the reaction was completed, the black glass bottle was taken out from the lightless environment to obtain a perfluoropolyether reaction mixture.

[0033] As a preferred embodiment of the method for determining the peroxide content in the perfluoropolyether of the present invention, the liquid chromatography-mass spectrometry separation method is used to separate the perfluoropolyether reaction mixture to obtain the separated perfluoropolyether peroxide, and the specific steps are as follows:

[0034] An LC-MS instrument was used, and a reverse phase C18 column was selected as the chromatographic column in the liquid chromatography-mass spectrometry separation method;

[0035] Prepare the mobile phase, using water + formic acid as the polar solvent phase A in the chromatographic column and acetonitrile + formic acid as the non-polar solvent phase B in the chromatographic column;

[0036] injecting the perfluoropolyether reaction mixture into an LC-MS instrument, and separating the perfluoropolyether reaction mixture using a gradient elution method in the LC-MS instrument;

[0037] During separation, a lower proportion of polar solvent phase A and a higher proportion of non-polar solvent phase B are used. During the separation process, the proportion of polar solvent phase A is gradually increased, while the proportion of non-polar solvent phase B is correspondingly reduced. As the proportion of polar solvent phase A increases, different compounds will be gradually separated.

[0038] Low-polarity compounds are gradually eluted and separated at the initial stage when the proportion of polar solvent A increases;

[0039] The medium polar compounds are gradually eluted and separated as the proportion of polar solvent A increases;

[0040] Highly polar compounds are eluted and separated at the later stage when the proportion of polar solvent A phase increases;

[0041] Finally, low-polarity compounds, medium-polarity compounds and high-polarity compounds of perfluoropolyether separated from the chromatographic column are obtained and marked as perfluoropolyether peroxides.

[0042] As a preferred embodiment of the method for determining the peroxide content in the perfluoropolyether of the present invention, the perfluoropolyether peroxide is ionized by an electrospray ion source, and the characteristic ions of the perfluoropolyether peroxide are detected by a mass spectrometer to obtain the mass spectrum information of the perfluoropolyether peroxide. The specific steps are as follows:

[0043] The perfluoropolyether peroxide separated by gradient elution is introduced into an electrospray ionization source (ESI), and the perfluoropolyether peroxide is evaporated to form charged ions;

[0044] Introducing charged ions into a triple quadrupole mass spectrometer TQMS, and setting a positive and negative ion switching mode in the triple quadrupole mass spectrometer TQMS;

[0045] In the positive ion mode, the triple quadrupole mass spectrometer TQMS is set to detect positively charged ions, detect compounds in the form of [M+H]+ ions in the charged ions, and obtain characteristic ion peaks in the form of [M+H]+ ions;

[0046] In the negative ion mode, the triple quadrupole mass spectrometer TQMS is set to detect negatively charged ions and detect compounds that form [MH]-negative ions in the charged ions to obtain characteristic ion peaks in the form of [MH]-ions;

[0047] In the triple quadrupole mass spectrometer TQMS, the precursor ions were summarized using the multiple reaction monitoring mode MRM based on the characteristic ion peaks in the form of [M+H]+ ions and the characteristic ion peaks in the form of [MH]- ions;

[0048] In the first quadrupole Q1 of the triple quadrupole mass spectrometer TQMS, the molecular weight m is set, then the mass range of [M+H]+ ions is m+1, and the mass range of [MH]- ions is m-1, and the parent ion-daughter ion pairs are selected by the full scan method;

[0049] The selected parent ion-daughter ion pair undergoes collision-induced dissociation (CID) through the second quadrupole Q2 of the triple quadrupole mass spectrometer TQMS, and the collision energy is adjusted to break the parent ion into fragment ions;

[0050] In the third quadrupole Q3 of the triple quadrupole mass spectrometer TQMS, the fragment ions generated by collision-induced dissociation (CID) are used as characteristic ions;

[0051] In MassHunter software, input characteristic ions and corresponding parent ion-daughter ion pairs;

[0052] Select a standard perfluoroalkyl peroxide with similar physicochemical properties to perfluoropolyether peroxide;

[0053] An automatic sampler was used to collect the concentration of the standard perfluoroalkyl peroxide solution as the known standard concentration;

[0054] The expected concentration range of perfluoropolyether peroxide is set as Z;

[0055] The concentration of the standard perfluoroalkyl peroxide solution covers the expected concentration range Z of perfluoropolyether peroxide, marked as C, and is injected in order from low concentration to high concentration;

[0056] When injecting, start data acquisition in MassHunter software to record the total ion current TIC, extracted ion current EIC and mass spectrum of each standard perfluoroalkyl peroxide injection;

[0057] On the ion current EIC, mark the retention time of the standard perfluoroalkyl peroxide;

[0058] In the mass spectrum, record the parent ion-daughter ion pair mass-to-charge ratio of the standard perfluoroalkyl peroxide;

[0059] The standard curve was established by linear regression algorithm to obtain the slope S and intercept I of the standard curve, and the least squares method was used to fit the linear equation to calculate the characteristic ion peak area A of the standard perfluoroalkyl peroxide. The expression is:

[0060] A=S·C+I;

[0061] Wherein, A is the characteristic ion peak area of ​​the standard perfluoroalkyl peroxide, S is the slope of the standard curve, F is the correction factor, I is the intercept, and C is the solution concentration of the standard perfluoroalkyl peroxide;

[0062] The parent ion-daughter ion pair mass-to-charge ratio, retention time and characteristic ion peak area A of the standard perfluoroalkyl peroxide are collected and used as the mass spectrum information of perfluoropolyether peroxide.

[0063] As a preferred embodiment of the method for determining the peroxide content in the perfluoropolyether of the present invention, the peroxide concentration of the perfluoropolyether is calculated based on the mass spectrum information of the perfluoropolyether peroxide, and the peroxide content in the perfluoropolyether is output based on the peroxide concentration of the perfluoropolyether, and the specific steps are as follows:

[0064] Based on the parent ion-daughter ion pair mass-to-charge ratio, retention time and characteristic ion peak area A of the standard perfluoroalkyl peroxide, the concentration of perfluoropolyether peroxide was calculated using the expression:

[0065]

[0066] Wherein, ∩ is the concentration of perfluoropolyether peroxide, A is the characteristic ion peak area, S is the slope of the standard curve, F is the correction factor, and U is the intercept;

[0067] Use solvent to make up to the scale line of the black glass bottle, marked as the volume V of perfluoropolyether peroxide;

[0068] Based on the volume V of perfluoropolyether peroxide and the concentration ∩ of perfluoropolyether peroxide, the peroxide content G in perfluoropolyether is calculated as follows:

[0069] G=∩·V

[0070] Wherein, ∩ is the concentration of perfluoropolyether peroxide, V is the volume of perfluoropolyether peroxide in the black glass bottle, and G is the peroxide content in perfluoropolyether;

[0071] The perfluoropolyether peroxide concentration ∩ is compared with the known standard solution concentration C to obtain a comparison result.

[0072] As a preferred embodiment of the method for determining the peroxide content in the perfluoropolyether of the present invention, the peroxide concentration of the perfluoropolyether is compared with the known concentration of the standard solution to obtain the comparison result, and the specific steps are as follows:

[0073] Compare the perfluoropolyether peroxide concentration ∩ with the known standard solution concentration C;

[0074] When the perfluoropolyether peroxide concentration ∩ is within the known standard solution concentration C, it indicates that the peroxide content in the perfluoropolyether sample is in line with expectations, which is marked as the quantitative result of perfluoropolyether peroxide;

[0075] When the peroxide concentration of perfluoropolyether exceeds the known standard solution concentration ∩>C, it means that the peroxide content in the perfluoropolyether is too high. Reduce the peroxide content in the perfluoropolyether sample and re-substitute the slope S and intercept I of the standard curve into the concentration calculation expression for calculation until ∩≤C.

[0076] In a second aspect, the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program is executed by the processor, any step of the method for determining the peroxide content in perfluoropolyether as described in the first aspect of the present invention is implemented.

[0077] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the method for determining the peroxide content in perfluoropolyether as described in the first aspect of the present invention is implemented.

[0078] The beneficial effects of the present invention are as follows: by selecting a clean and dry sample bottle and a high-precision electronic balance GS8202, accurate sample collection is achieved, the reliability of subsequent analysis results is improved, experimental errors are reduced, and the accuracy of the final measurement results is guaranteed; by using a microwave transparent glass bottle and a polar modified organic solvent methanol-water mixture, and setting the microwave power and processing time, efficient pretreatment is achieved, the extraction time is significantly shortened, and the extraction efficiency is improved; by introducing a bifunctional probe solution and reacting in a lightless environment, the reaction efficiency of the perfluoropolyether solution is accurately calculated, which not only improves the controllability and repeatability of the reaction, but also optimizes the reaction conditions through a reaction kinetic function; by using an LC-MS instrument and selecting a reversed-phase C18 column, as well as a gradient elution method, effective separation of perfluoropolyether peroxides is achieved; gradient elution significantly improves separation resolution and efficiency, ensures effective separation of each component in a complex sample, and provides pure target compounds for subsequent mass spectrometry detection, thereby improving the accuracy of quantitative analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0080] Figure 1This is a flow chart of the method for determining the peroxide content in perfluoropolyether in Example 1.

[0081] Figure 2 This is a flow chart of the perfluoropolyether peroxide in Example 1. DETAILED DESCRIPTION

[0082] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0083] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0084] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0085] Example 1, reference Figure 1 and Figure 2 , which is the first embodiment of the present invention, provides a method for determining the peroxide content in perfluoropolyether, comprising the following steps:.

[0086] S1. collecting perfluoropolyether by a balance weighing method to obtain a perfluoropolyether sample;

[0087] Furthermore, choose clean and dry sample bottles and high-precision electronic balance GS8202;

[0088] Place the sample bottle on the high-precision electronic balance GS8202 and open the wind shield of the high-precision electronic balance GS8202;

[0089] Using a pipette, taking out the perfluoropolyether from the container and adding it into a sample bottle to obtain a perfluoropolyether sample;

[0090] It should be noted that during the weighing process, ensure that all operations are carried out in a dust-free, low-humidity environment to prevent the sample from being contaminated or hygroscopic. The use of a high-precision electronic balance GS8202 can ensure the accuracy of the weighing. The use of a wind shield can reduce the impact of air flow on the weighing results. The selection and calibration of the pipette is also crucial to ensure the accuracy of sample transfer.

[0091] S2, pretreating the perfluoropolyether sample by microwave-assisted extraction technology to obtain a perfluoropolyether solution after microwave extraction;

[0092] Furthermore, a microwave transparent glass bottle was selected as a microwave-assisted extraction container, and a polar modified organic solvent methanol-water mixture was prepared;

[0093] The perfluoropolyether sample was transferred into a microwave transparent glass bottle, and a methanol-water mixture was added into the microwave transparent glass bottle;

[0094] The microwave transparent glass bottle after adding the methanol-water mixture was placed in a microwave-assisted extraction instrument for microwave-assisted extraction, and the microwave power of the microwave-assisted extraction instrument was set to 800 W, and the processing time was set to 5 minutes;

[0095] After the microwave-assisted extraction is completed, the microwave transparent glass bottle is taken out and naturally cooled to room temperature 25° C., and a perfluoropolyether solution after microwave extraction is obtained;

[0096] It should be noted that the choice of microwave transparent glass bottles is to ensure that microwave energy can evenly penetrate the sample and improve the extraction efficiency. The methanol-water mixture, as a polar modified organic solvent, helps to dissolve perfluoropolyether and its peroxide derivatives. The microwave power of the microwave-assisted extractor is set to 800 W, and the processing time is set to 5 minutes to avoid decomposition or volatilization of the target compound due to excessive heating. Natural cooling to room temperature 25°C can prevent the influence of sudden temperature changes on the stability of the solution.

[0097] S3, adding the bifunctional probe solution to the perfluoropolyether solution, calculating the reaction efficiency of the perfluoropolyether solution in a black glass bottle under light-free conditions, and obtaining a perfluoropolyether reaction mixture;

[0098] Furthermore, a black glass bottle is selected as a reaction container, and the perfluoropolyether solution after microwave extraction is added into the black glass bottle;

[0099] The dual-function probe solution was added into the black glass bottle containing the microwave-extracted perfluoropolyether solution;

[0100] Place the black glass bottle containing the microwave-extracted perfluoropolyether solution and the dual-function probe solution in a light-free environment;

[0101] Based on the principle of reaction kinetics, the reaction temperature was set at 25°C, the reaction time was set at 1 hour, and during the reaction process, the reaction kinetic function was introduced to calculate the reaction efficiency of the bifunctional probe solution and the perfluoropolyether solution after microwave extraction under different conditions. The expression is:

[0102]

[0103] Where R is the reaction efficiency, is the binding concentration of the probe solution after the reaction, H is the concentration of the bifunctional probe solution, K is the binding rate constant, T is the reaction time, t is the time constant, and exp is the exponential function during the reaction;

[0104] Based on the principle of reaction kinetics, the threshold W of reaction efficiency is set to compare with the reaction efficiency R;

[0105] When R<W, the initial concentration H of the bifunctional probe solution is gradually increased until R≥W;

[0106] Based on the mass spectrometry database METLIN, the optimal reaction threshold was determined to be W ≥ 90%;

[0107] When R ≥ W, it is confirmed that the binding between the bifunctional probe solution and the perfluoropolyether peroxide after microwave extraction meets the expected degree and ensures that only perfluoropolyether peroxide is detected during the reaction;

[0108] After the reaction is completed, the black glass bottle is taken out from the lightless environment to obtain a perfluoropolyether reaction mixture;

[0109] It should be noted that black glass bottles are used as reaction containers, which can effectively prevent the occurrence of photosensitive reactions in a lightless environment. The selection of bifunctional probe solutions should be based on their specific binding ability with the target compound to ensure that the reaction is highly selective and sensitive. The introduction of reaction kinetic functions can help optimize reaction conditions, improve reaction efficiency, and ensure the reliability of calculation results. By gradually adjusting the initial concentration of the bifunctional probe solution, the optimal reaction conditions can be found to ensure that the reaction efficiency reaches or exceeds the set threshold.

[0110] S4, separating the perfluoropolyether reaction mixture by liquid chromatography-mass spectrometry separation method to obtain separated perfluoropolyether peroxide;

[0111] Furthermore, an LC-MS instrument is used, and a reverse phase C18 column is selected as the chromatographic column in the liquid chromatography-mass spectrometry separation method;

[0112] Prepare the mobile phase, using water + formic acid as the polar solvent phase A in the chromatographic column and acetonitrile + formic acid as the non-polar solvent phase B in the chromatographic column;

[0113] Among them, formic acid, as a weak acid, can promote the deprotonation or hydrogenation ionization process in the electrospray ionization source (ESI). For perfluoropolyether peroxide, adding a small amount of formic acid helps to form stable [MH]- or [M+H]+ ions, thereby improving the detection sensitivity;

[0114] Water is a polar solvent that can dissolve compounds with higher polarity. Adding formic acid not only improves the ionization efficiency, but also improves the solubility of perfluoropolyether peroxide. Acetonitrile is a commonly used non-polar solvent that can effectively dissolve non-polar or weakly polar compounds. Adding formic acid also helps to improve the ionization efficiency of perfluoropolyether peroxide.

[0115] injecting the perfluoropolyether reaction mixture into an LC-MS instrument, and separating the perfluoropolyether reaction mixture using a gradient elution method in the LC-MS instrument;

[0116] During separation, a lower proportion of polar solvent phase A and a higher proportion of non-polar solvent phase B are used. During the separation process, the proportion of polar solvent phase A is gradually increased, while the proportion of non-polar solvent phase B is correspondingly reduced. As the proportion of polar solvent phase A increases, different compounds will be gradually separated.

[0117] Low-polarity compounds are gradually eluted and separated at the initial stage when the proportion of polar solvent A increases;

[0118] The medium polar compounds are gradually eluted and separated as the proportion of polar solvent A increases;

[0119] Highly polar compounds are eluted and separated at the later stage when the proportion of polar solvent A phase increases;

[0120] Finally, low-polarity compounds, medium-polarity compounds and high-polarity compounds of perfluoropolyether separated from the chromatographic column are obtained and marked as perfluoropolyether peroxides;

[0121] It should be noted that the selection of the reverse phase C18 column is based on its good separation effect on non-polar and medium polar compounds. The gradient elution method can achieve step-by-step separation according to the polarity differences of different compounds, ensuring the efficiency and resolution of the separation process. By gradually increasing the proportion of polar solvent A phase, compounds of different polarities can be eluted and separated in sequence, thereby obtaining a clear separation spectrum. The perfluoropolyether peroxide finally separated can be confirmed by retention time and mass-to-charge ratio (m / z), ensuring the effective separation and identification of the target compound.

[0122] S5. ionizing the perfluoropolyether peroxide using an electrospray ion source, and detecting characteristic ions of the perfluoropolyether peroxide using a mass spectrometer to obtain mass spectrum information of the perfluoropolyether peroxide;

[0123] Furthermore, the perfluoropolyether peroxide separated by gradient elution is introduced into an electrospray ionization source ESI, and the perfluoropolyether peroxide is evaporated to form charged ions;

[0124] Introducing charged ions into a triple quadrupole mass spectrometer TQMS, and setting a positive and negative ion switching mode in the triple quadrupole mass spectrometer TQMS;

[0125] In the positive ion mode, the triple quadrupole mass spectrometer TQMS is set to detect positively charged ions, detect compounds in the form of [M+H]+ ions in the charged ions, and obtain characteristic ion peaks in the form of [M+H]+ ions;

[0126] In the negative ion mode, the triple quadrupole mass spectrometer TQMS is set to detect negatively charged ions and detect compounds that form [MH]-negative ions in the charged ions to obtain characteristic ion peaks in the form of [MH]-ions;

[0127] In the triple quadrupole mass spectrometer TQMS, the precursor ions were summarized using the multiple reaction monitoring mode MRM based on the characteristic ion peaks in the form of [M+H]+ ions and the characteristic ion peaks in the form of [MH]- ions;

[0128] In the first quadrupole Q1 of the triple quadrupole mass spectrometer TQMS, the molecular weight m is set, then the mass range of [M+H]+ ions is m+1, and the mass range of [MH]- ions is m-1, and the parent ion-daughter ion pairs are selected by the full scan method;

[0129] The selected parent ion-daughter ion pair undergoes collision-induced dissociation (CID) through the second quadrupole Q2 of the triple quadrupole mass spectrometer TQMS, and the collision energy is adjusted to break the parent ion into fragment ions;

[0130] In the third quadrupole Q3 of the triple quadrupole mass spectrometer TQMS, the fragment ions generated by collision-induced dissociation (CID) are used as characteristic ions;

[0131] In MassHunter software, input characteristic ions and corresponding parent ion-daughter ion pairs;

[0132] Select a standard perfluoroalkyl peroxide with similar physicochemical properties to perfluoropolyether peroxide;

[0133] An automatic sampler was used to collect the concentration of the standard perfluoroalkyl peroxide solution as the known standard concentration;

[0134] The expected concentration range of perfluoropolyether peroxide is set as Z;

[0135] The concentration of the standard perfluoroalkyl peroxide solution covers the expected concentration range Z of perfluoropolyether peroxide, marked as C, and is injected in order from low concentration to high concentration;

[0136] When injecting, start data acquisition in MassHunter software to record the total ion current TIC, extracted ion current EIC and mass spectrum of each standard perfluoroalkyl peroxide injection;

[0137] On the ion current EIC, mark the retention time of the standard perfluoroalkyl peroxide;

[0138] In the mass spectrum, record the parent ion-daughter ion pair mass-to-charge ratio of the standard perfluoroalkyl peroxide;

[0139] The standard curve was established by linear regression algorithm to obtain the slope S and intercept I of the standard curve, and the least squares method was used to fit the linear equation to calculate the characteristic ion peak area A of the standard perfluoroalkyl peroxide. The expression is:

[0140] A=S·C+I;

[0141] Wherein, A is the characteristic ion peak area of ​​the standard perfluoroalkyl peroxide, S is the slope of the standard curve, F is the correction factor, I is the intercept, and C is the solution concentration of the standard perfluoroalkyl peroxide;

[0142] The parent ion-daughter ion pair mass-to-charge ratio, retention time and characteristic ion peak area A of the standard perfluoroalkyl peroxide are collected and used as the mass spectrum information of perfluoropolyether peroxide;

[0143] It should be noted that the selection of an electrospray ion source (ESI) can effectively improve the ionization efficiency and ensure the formation and transmission of charged ions. The application of positive and negative ion switching modes enables compounds of different polarities to be effectively detected, improving the comprehensiveness of the analysis. The selective monitoring of the multiple reaction monitoring mode (MRM) can significantly improve the signal-to-noise ratio and ensure that the characteristic ion pairs of the target compounds are accurately detected. The establishment of the standard curve and the application of the linear regression algorithm ensure the accuracy of the quantitative results. The least squares method for fitting the linear equation can minimize errors and ensure the reliability of the concentration calculation.

[0144] S6. Calculating the concentration of perfluoropolyether peroxide based on the mass spectrum information of the perfluoropolyether peroxide, and outputting the peroxide content in the perfluoropolyether based on the perfluoropolyether peroxide concentration;

[0145] Furthermore, based on the parent ion-daughter ion pair mass-to-charge ratio, retention time and characteristic ion peak area A of the standard perfluoroalkyl peroxide, the concentration of perfluoropolyether peroxide is calculated as follows:

[0146]

[0147] Wherein, ∩ is the concentration of perfluoropolyether peroxide, A is the characteristic ion peak area, S is the slope of the standard curve, F is the correction factor, and I is the intercept;

[0148] Use solvent to make up to the scale line of the black glass bottle, marked as the volume V of perfluoropolyether peroxide;

[0149] Based on the volume V of perfluoropolyether peroxide and the concentration ∩ of perfluoropolyether peroxide, the peroxide content G in perfluoropolyether is calculated as follows:

[0150] G=∩·V

[0151] Wherein, ∩ is the concentration of perfluoropolyether peroxide, V is the volume of perfluoropolyether peroxide in the black glass bottle, and G is the peroxide content in perfluoropolyether;

[0152] The perfluoropolyether peroxide concentration ∩ is compared with the known standard solution concentration C to obtain a comparison result;

[0153] Compare the perfluoropolyether peroxide concentration ∩ with the known standard solution concentration C;

[0154] When the perfluoropolyether peroxide concentration ∩ is within the known standard solution concentration C, it indicates that the peroxide content in the perfluoropolyether sample meets the industry standard and is marked as the quantitative result of perfluoropolyether peroxide;

[0155] When the peroxide concentration of perfluoropolyether exceeds the known standard solution concentration ∩>C, it means that the peroxide content in the perfluoropolyether is too high. It is necessary to reduce the peroxide content in the perfluoropolyether sample and check the R of the standard curve. 2 value, ensuring that it is close to Then, the slope S and intercept I of the standard curve are substituted into the concentration calculation expression again for calculation until ∩≤C;

[0156] It should be noted that when calculating the concentration of perfluoropolyether peroxide based on mass spectrometry information, it is necessary to ensure that the slope and intercept of the standard curve used are derived from a reliable linear regression analysis and that R 2 The value is close to 1, indicating a good linear relationship. When calculating the peroxide content in perfluoropolyether, the total volume or total mass of the sample needs to be clarified to ensure the accuracy of the content calculation. Comparing the calculated peroxide concentration with the known standard solution concentration can not only verify the accuracy of the experimental results, but also provide a basis for subsequent adjustments. When it is found that the peroxide concentration of perfluoropolyether exceeds the expected range, the experimental conditions and the process of establishing the standard curve should be carefully checked to ensure that all parameters meet the requirements. If necessary, repeat the experiment to obtain more accurate results.

[0157] This embodiment also provides a computer device, which is suitable for the method for determining the peroxide content in perfluoropolyether, including: a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions to implement the method for determining the peroxide content in perfluoropolyether proposed in the above embodiment.

[0158] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0159] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for determining the peroxide content in perfluoropolyether as proposed in the above embodiment is implemented; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, referred to as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, referred to as EEPROM), erasable programmable read-only memory (Erasable Programmable Read Only Memory, referred to as EPROM), programmable read-only memory (Programmable Red-Only Memory, referred to as PROM), read-only memory (Read-Only Memory, referred to as ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0160] In summary, the present invention realizes accurate sample collection by selecting clean and dry sample bottles and a high-precision electronic balance GS8202, improves the reliability of subsequent analysis results, reduces experimental errors, and ensures the accuracy of the final measurement results. By using a microwave transparent glass bottle and a polar modified organic solvent methanol-water mixture, and setting the microwave power and processing time, efficient pretreatment is achieved, the extraction time is significantly shortened, and the extraction efficiency is improved. By introducing a bifunctional probe solution and reacting in a lightless environment, the reaction efficiency of the perfluoropolyether solution is accurately calculated, which not only improves the controllability and repeatability of the reaction, but also optimizes the reaction conditions through the reaction kinetic function. By using an LC-MS instrument and selecting a reversed-phase C18 column, as well as a gradient elution method, effective separation of perfluoropolyether peroxides is achieved. Gradient elution significantly improves the separation resolution and efficiency, ensures the effective separation of each component in a complex sample, and provides pure target compounds for subsequent mass spectrometry detection, thereby improving the accuracy of quantitative analysis.

[0161] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for determining the peroxide content in perfluoropolyether, characterized in that: include: The perfluoropolyether is collected by a balance weighing method to obtain a perfluoropolyether sample; The perfluoropolyether sample is pretreated by microwave-assisted extraction technology to obtain a perfluoropolyether solution after microwave extraction; The bifunctional probe solution is added to the perfluoropolyether solution, and the reaction efficiency of the perfluoropolyether solution is calculated in a black glass bottle under light-free conditions to obtain a perfluoropolyether reaction mixture; The perfluoropolyether reaction mixture is separated by a liquid chromatography-mass spectrometry separation method to obtain separated perfluoropolyether peroxide; The perfluoropolyether peroxide is ionized by using an electrospray ion source, and the characteristic ions of the perfluoropolyether peroxide are detected by using a mass spectrometer to obtain mass spectrum information of the perfluoropolyether peroxide; Based on the mass spectrum information of the perfluoropolyether peroxide, the concentration of the perfluoropolyether peroxide is calculated, and the peroxide content in the perfluoropolyether is output based on the concentration of the perfluoropolyether peroxide.

2. The method for determining the peroxide content in perfluoropolyether according to claim 1, characterized in that: The method of using a balance weighing method to collect the perfluoropolyether to obtain a perfluoropolyether sample comprises the following specific steps: Choose clean and dry sample bottles and high-precision electronic balance GS8202; Place the sample bottle on the high-precision electronic balance GS8202 and open the wind shield of the high-precision electronic balance GS8202; The perfluoropolyether in the container is taken out by using a pipette and added into a sample bottle to obtain a perfluoropolyether sample.

3. The method for determining the peroxide content in perfluoropolyether according to claim 2, characterized in that: The perfluoropolyether sample is pretreated by microwave-assisted extraction technology to obtain a perfluoropolyether solution after microwave extraction, and the specific steps are: A microwave transparent glass bottle was selected as a microwave-assisted extraction container, and a polar modified organic solvent methanol-water mixture was prepared; The perfluoropolyether sample was transferred into a microwave transparent glass bottle, and a methanol-water mixture was added into the microwave transparent glass bottle; The microwave transparent glass bottle after adding the methanol-water mixture is placed in a microwave-assisted extraction instrument for microwave-assisted extraction, and the microwave power and processing time of the microwave-assisted extraction instrument are set; After the microwave-assisted extraction is completed, the microwave transparent glass bottle is taken out and naturally cooled to room temperature, and a perfluoropolyether solution after microwave extraction is obtained.

4. The method for determining the peroxide content in perfluoropolyether according to claim 3, characterized in that: The bifunctional probe solution is added to the perfluoropolyether solution after microwave extraction, and the reaction efficiency of the perfluoropolyether solution is calculated in a black glass bottle under light-free conditions to obtain a perfluoropolyether reaction mixture, and the specific steps are as follows: A black glass bottle is selected as a reaction container, and the perfluoropolyether solution after microwave extraction is added into the black glass bottle; The dual-function probe solution was added into the black glass bottle containing the microwave-extracted perfluoropolyether solution; Place the black glass bottle containing the microwave-extracted perfluoropolyether solution and the dual-function probe solution in a light-free environment; The reaction temperature and reaction time were set, and during the reaction process, the reaction kinetic function was introduced to calculate the reaction efficiency of the bifunctional probe solution and the perfluoropolyether solution after microwave extraction under different conditions. The expression is: Where R is the reaction efficiency, is the binding concentration of the probe solution after the reaction, H is the concentration of the bifunctional probe solution, K is the binding rate constant, T is the reaction time, t is the time constant, and exp is the exponential function during the reaction; Setting a threshold value W of the reaction efficiency to compare with the reaction efficiency R; When R<W, the initial concentration H of the bifunctional probe solution is gradually increased until R≥W; When R ≥ W, it is confirmed that the binding between the bifunctional probe solution and the perfluoropolyether peroxide after microwave extraction meets the expected degree and ensures that only perfluoropolyether peroxide is detected during the reaction; After the reaction was completed, the black glass bottle was taken out from the lightless environment to obtain a perfluoropolyether reaction mixture.

5. The method for determining the peroxide content in perfluoropolyether according to claim 4, characterized in that: The method of using a liquid chromatography-mass spectrometry separation method to separate the perfluoropolyether reaction mixture to obtain the separated perfluoropolyether peroxide comprises the following specific steps: An LC-MS instrument was used, and a reverse phase C18 column was selected as the chromatographic column in the liquid chromatography-mass spectrometry separation method; Prepare the mobile phase, using water + formic acid as the polar solvent phase A in the chromatographic column and acetonitrile + formic acid as the non-polar solvent phase B in the chromatographic column; injecting the perfluoropolyether reaction mixture into an LC-MS instrument, and separating the perfluoropolyether reaction mixture using a gradient elution method in the LC-MS instrument; During separation, a lower proportion of polar solvent phase A and a higher proportion of non-polar solvent phase B are used. During the separation process, the proportion of polar solvent phase A is gradually increased, while the proportion of non-polar solvent phase B is correspondingly reduced. As the proportion of polar solvent phase A increases, different compounds will be gradually separated. Low-polarity compounds are gradually eluted and separated at the initial stage when the proportion of polar solvent A increases; The medium polar compounds are gradually eluted and separated as the proportion of polar solvent A increases; Highly polar compounds are eluted and separated at the later stage when the proportion of polar solvent A phase increases; Finally, low-polarity compounds, medium-polarity compounds and high-polarity compounds of perfluoropolyether separated from the chromatographic column are obtained and marked as perfluoropolyether peroxides.

6. The method for determining the peroxide content in perfluoropolyether according to claim 5, characterized in that: The method of ionizing the perfluoropolyether peroxide by an electrospray ion source and detecting the characteristic ions of the perfluoropolyether peroxide by a mass spectrometer to obtain the mass spectrum information of the perfluoropolyether peroxide comprises the following specific steps: The perfluoropolyether peroxide separated by gradient elution is introduced into an electrospray ionization source (ESI), and the perfluoropolyether peroxide is evaporated to form charged ions; Introducing charged ions into a triple quadrupole mass spectrometer TQMS, and setting a positive and negative ion switching mode in the triple quadrupole mass spectrometer TQMS; In the positive ion mode, the triple quadrupole mass spectrometer TQMS is set to detect positively charged ions, detect compounds in the form of [M+H]+ ions in the charged ions, and obtain characteristic ion peaks in the form of [M+H]+ ions; In the negative ion mode, the triple quadrupole mass spectrometer TQMS is set to detect negatively charged ions and detect compounds that form [MH]-negative ions in the charged ions to obtain characteristic ion peaks in the form of [MH]-ions; In the triple quadrupole mass spectrometer TQMS, the precursor ions were summarized using the multiple reaction monitoring mode MRM based on the characteristic ion peaks in the form of [M+H]+ ions and the characteristic ion peaks in the form of [MH]- ions; In the first quadrupole Q1 of the triple quadrupole mass spectrometer TQMS, the molecular weight m is set, then the mass range of [M+H]+ ions is m+1, and the mass range of [MH]- ions is m-1, and the parent ion-daughter ion pairs are selected by the full scan method; The selected parent ion-daughter ion pair undergoes collision-induced dissociation (CID) through the second quadrupole Q2 of the triple quadrupole mass spectrometer TQMS, and the collision energy is adjusted to break the parent ion into fragment ions; In the third quadrupole Q3 of the triple quadrupole mass spectrometer TQMS, the fragment ions generated by collision-induced dissociation (CID) are used as characteristic ions; In MassHunter software, input characteristic ions and corresponding parent ion-daughter ion pairs; Select a standard perfluoroalkyl peroxide with similar physicochemical properties to perfluoropolyether peroxide; An automatic sampler was used to collect the concentration of the standard perfluoroalkyl peroxide solution as the known standard concentration; The expected concentration range of perfluoropolyether peroxide is set as Z; The concentration of the standard perfluoroalkyl peroxide solution covers the expected concentration range Z of perfluoropolyether peroxide, marked as C, and is injected in order from low concentration to high concentration; When injecting, start data acquisition in MassHunter software to record the total ion current TIC, extracted ion current EIC and mass spectrum of each standard perfluoroalkyl peroxide injection; On the ion current EIC, mark the retention time of the standard perfluoroalkyl peroxide; In the mass spectrum, record the parent ion-daughter ion pair mass-to-charge ratio of the standard perfluoroalkyl peroxide; The standard curve was established by linear regression algorithm to obtain the slope S and intercept I of the standard curve, and the least squares method was used to fit the linear equation to calculate the characteristic ion peak area A of the standard perfluoroalkyl peroxide. The expression is: A=S·C+I; Wherein, A is the characteristic ion peak area of ​​the standard perfluoroalkyl peroxide, S is the slope of the standard curve, F is the correction factor, I is the intercept, and C is the solution concentration of the standard perfluoroalkyl peroxide; The parent ion-daughter ion pair mass-to-charge ratio, retention time and characteristic ion peak area A of the standard perfluoroalkyl peroxide are collected and used as the mass spectrum information of perfluoropolyether peroxide.

7. The method for determining the peroxide content in perfluoropolyether according to claim 6, characterized in that: The method of calculating the concentration of perfluoropolyether peroxide based on the mass spectrum information of perfluoropolyether peroxide and outputting the peroxide content in perfluoropolyether based on the perfluoropolyether peroxide concentration comprises the following specific steps: Based on the parent ion-daughter ion pair mass-to-charge ratio, retention time and characteristic ion peak area A of the standard perfluoroalkyl peroxide, the concentration of perfluoropolyether peroxide was calculated using the expression: Wherein, ∩ is the concentration of perfluoropolyether peroxide, A is the characteristic ion peak area, S is the slope of the standard curve, F is the correction factor, and I is the intercept; Use solvent to make up to the scale line of the black glass bottle, marked as the volume V of perfluoropolyether peroxide; Based on the volume V of perfluoropolyether peroxide and the concentration ∩ of perfluoropolyether peroxide, the peroxide content G in perfluoropolyether is calculated as follows: G=∩·V Wherein, ∩ is the concentration of perfluoropolyether peroxide, V is the volume of perfluoropolyether peroxide in the black glass bottle, and G is the peroxide content in perfluoropolyether; The perfluoropolyether peroxide concentration ∩ is compared with the known standard solution concentration C to obtain a comparison result.

8. The method for determining the peroxide content in perfluoropolyether according to claim 6, wherein: The concentration of the perfluoropolyether peroxide is compared with the known concentration of the standard solution to obtain a comparison result, and the specific steps are as follows: When the perfluoropolyether peroxide concentration ∩ is within the known standard solution concentration C, it indicates that the peroxide content in the perfluoropolyether sample is in line with expectations, which is marked as the quantitative result of perfluoropolyether peroxide; When the peroxide concentration of perfluoropolyether exceeds the known standard solution concentration ∩>C, it means that the peroxide content in the perfluoropolyether is too high. Reduce the peroxide content in the perfluoropolyether sample and re-substitute the slope S and intercept I of the standard curve into the concentration calculation expression for calculation until ∩≤C.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for determining the peroxide content in perfluoropolyether according to any one of claims 1 to 8 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for determining the peroxide content in perfluoropolyether according to any one of claims 1 to 8 are implemented.

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