Method for determining peroxide content in perfluoropolyethers

Abstract

This invention discloses a method for determining the peroxide content in perfluoropolyethers, relating to the field of perfluoropolyether peroxide content determination technology. The method includes: collecting perfluoropolyether using a balance weighing method to obtain a perfluoropolyether sample; pretreating the perfluoropolyether sample using microwave-assisted extraction technology to obtain a microwave-extracted perfluoropolyether solution; adding a bifunctional probe solution to the perfluoropolyether solution and calculating the reaction efficiency of the perfluoropolyether solution under light-free conditions using a black glass bottle to obtain a perfluoropolyether reaction mixture; separating the perfluoropolyether reaction mixture using liquid chromatography-mass spectrometry to obtain separated perfluoropolyether peroxides; ionizing the perfluoropolyether peroxides using an electrospray ionization source and detecting the characteristic ions of the perfluoropolyether peroxides using a mass spectrometer to obtain the mass spectrometric information of the perfluoropolyether peroxides; and based on the mass spectrometric information of the perfluoropolyether peroxides.

Description

Technical Field

[0001] This invention relates to the field of peroxide content determination technology for perfluoropolyethers, and in particular to a method for determining the peroxide content in perfluoropolyethers. Background Technology

[0002] Peroxide content determination in perfluoropolyethers (PFPEs) is an analytical technique specifically designed to quantify the concentration of peroxides in PFPEs. It aims to accurately assess potential unstable components in these high-performance lubricants and protective materials. The technique ensures the determination of peroxides in PFPEs 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 field of perfluoropolyether peroxide content determination technology, traditional methods rely on ordinary electronic balances for sample weighing. These balances lack sufficient accuracy and stability, especially when operating in open environments, where they are easily affected by external factors such as airflow and temperature changes. Furthermore, the selection and handling of sample vials are not strict enough, easily introducing impurities or contaminants. At the same time, traditional extraction methods have low extraction efficiency, resulting in the target compound not being completely dissolved or extracted, leading to a lower final measurement result that cannot accurately reflect the peroxide content in the sample. In addition, high-temperature extraction conditions may damage the structure of the target compound, affecting its stability and detection accuracy. Moreover, in traditional mass spectrometry detection methods, the selection of ion sources and the setting of detection modes are not optimized enough, resulting in the target compound not being effectively ionized or detected. Summary of the Invention

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

[0005] Therefore, this invention provides a method for determining the peroxide content in perfluoropolyethers, which solves the problems of low extraction efficiency in traditional extraction methods, resulting in the incomplete dissolution or extraction of the target compound, leading to a lower final determination result that cannot accurately reflect the peroxide content in the sample. In addition, high-temperature extraction conditions may damage the structure of the target compound, affecting its stability and detection accuracy.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

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

[0008] The perfluoropolyether sample was pretreated by microwave-assisted extraction technology to obtain a microwave-extracted perfluoropolyether solution.

[0009] A bifunctional probe solution was added to a perfluoropolyether solution, and the reaction efficiency of the perfluoropolyether solution was calculated under light-free conditions using a black glass bottle to obtain the perfluoropolyether reaction mixture.

[0010] The perfluoropolyether reaction mixture was separated by liquid chromatography-mass spectrometry to obtain the separated perfluoropolyether peroxide;

[0011] Perfluoropolyether peroxide was ionized using an electrospray ionization source, and its characteristic ions were detected by mass spectrometry to obtain its mass spectrometric information.

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

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

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

[0015] Place the sample vial on the GS8202 high-precision electronic balance and open the windproof cover of the GS8202 high-precision electronic balance;

[0016] Use a pipette to remove the perfluoropolyether from the container and add it to the sample vial to obtain a perfluoropolyether sample.

[0017] As a preferred embodiment of the method for determining the peroxide content in perfluoropolyethers according to the present invention, the specific steps of pretreating the perfluoropolyether sample using microwave-assisted extraction technology to obtain a microwave-extracted perfluoropolyether solution are as follows:

[0018] Microwave-safe transparent glass bottles were selected as microwave-assisted extraction containers, and a mixture of methanol and water with polar modified organic solvent was prepared.

[0019] Transfer the perfluoropolyether sample to a microwave-safe transparent glass bottle, and add a methanol-water mixture to the bottle.

[0020] The microwave-assisted extraction was carried out in a microwave-assisted extraction instrument after adding the methanol-water mixture. The microwave power and processing time of the microwave-assisted extraction instrument were set.

[0021] After microwave-assisted extraction, the microwave-safe transparent glass bottle was removed and allowed to cool naturally to room temperature, yielding a microwave-extracted perfluoropolyether solution.

[0022] As a preferred embodiment of the method for determining the peroxide content in perfluoropolyethers according to the present invention, the steps of adding the bifunctional probe solution to the microwave-extracted perfluoropolyether solution, calculating the reaction efficiency of the perfluoropolyether solution under light-free conditions using a black glass bottle, and obtaining the perfluoropolyether reaction mixture are as follows:

[0023] A black glass bottle was selected as the reaction vessel, and a perfluoropolyether solution extracted by microwave was added to the black glass bottle.

[0024] Add the bifunctional probe solution to a black glass bottle containing a microwave-extracted perfluoropolyether solution;

[0025] Place the black glass bottle containing the microwave-extracted perfluoropolyether solution and the bifunctional probe solution in a dark environment.

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

[0027]

[0028] Where R is the reaction efficiency. denoted as , where 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 in the reaction process.

[0029] Set a threshold W for reaction efficiency and compare it with the reaction efficiency R;

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

[0031] When R≥W, confirm that the binding between the bifunctional probe solution and the microwave-extracted perfluoropolyether peroxide meets the expected degree, and ensure that only perfluoropolyether peroxide is detected during the reaction process;

[0032] After the reaction was completed, the black glass bottle was removed from the dark environment, and a perfluoropolyether reaction mixture was obtained.

[0033] In a preferred embodiment of the method for determining the peroxide content in perfluoropolyethers according to the present invention, the method for separating the perfluoropolyether reaction mixture using liquid chromatography-mass spectrometry to obtain the separated perfluoropolyether peroxides comprises the following steps:

[0034] LC-MS instrument was used, and a reversed-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] The perfluoropolyether reaction mixture was injected into an LC-MS instrument, and the perfluoropolyether reaction mixture was separated in the LC-MS instrument using a gradient elution method;

[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 decreased. As the proportion of polar solvent phase A increases, different compounds will be gradually separated.

[0038] Low-polarity compounds are gradually eluted and separated in the initial stage of increasing proportion of polar solvent A phase;

[0039] The moderately polar compound was gradually eluted and separated as the proportion of the polar solvent A phase increased;

[0040] Highly polar compounds are eluted and separated in the later stages as the proportion of polar solvent A increases;

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

[0042] As a preferred embodiment of the method for determining the peroxide content in perfluoropolyethers according to the present invention, the method involves: ionizing the perfluoropolyether peroxides using an electrospray ionization source and detecting the characteristic ions of the perfluoropolyether peroxides using a mass spectrometer to obtain the mass spectrometric information of the perfluoropolyether peroxides. The specific steps are as follows:

[0043] The perfluoropolyether peroxide, after gradient elution separation, is introduced into the electrospray ionization source ESI and evaporated to form charged ions.

[0044] Charged ions were introduced into a triple quadrupole mass spectrometer (TQMS), and a positive and negative ion switching mode was set in the TQMS.

[0045] In positive ion mode, the triple quadrupole mass spectrometer (TQMS) is set to detect positively charged ions, detect compounds that form [M+H]+ ions among charged ions, and obtain the characteristic ion peak of [M+H]+ ions.

[0046] In negative ion mode, the triple quadrupole mass spectrometer (TQMS) is set to detect negatively charged ions and to detect compounds that form [MH]- anions among charged ions, thus obtaining the characteristic ion peaks in the form of [MH]- ions.

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

[0048] In the first-stage quadrupole Q1 of the triple quadrupole mass spectrometer (TQMS), with the molecular weight m set, the mass range of [M+H]+ ions is m+1, and the mass range of [MH]- ions is m-1. The parent ion-daughter ion pair is selected by the full scan method.

[0049] The selected mother ion-daughter ion pair undergoes collision-induced dissociation (CID) via the second-stage quadrupole Q2 of a triple quadrupole mass spectrometer (TQMS), and the collision energy is adjusted to cause the mother ion to fragment into fragment ions.

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

[0051] In the MassHunter software, input the characteristic ion and the corresponding mother ion-daughter ion pair;

[0052] Select perfluoroalkyl peroxide as a standard that has similar physicochemical properties to perfluoropolyether peroxide;

[0053] The concentration of the perfluoroalkyl peroxide solution was collected using an autosampler as a 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 the perfluoropolyether peroxide, and is marked as C. The solutions are injected sequentially from low concentration to high concentration.

[0056] During sample injection, data acquisition was initiated in MassHunter software to record the total ion chromatogram (TIC), extracted ion chromatogram (EIC), and mass spectrum for each injection of the perfluoroalkyl peroxide standard.

[0057] The retention times of the standard perfluoroalkyl peroxide were marked on the ion chromatogram EIC.

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

[0059] A standard curve was established using a linear regression algorithm to obtain the slope S and intercept I. The linear equation was then fitted using the least squares method to calculate the characteristic ion peak area A of the perfluoroalkyl peroxide standard. The expression is as follows:

[0060] A = S·C + I;

[0061] Where 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 mass-to-charge ratio of the parent ion-daughter ion pair, retention time, and characteristic ion peak area A of the standard perfluoroalkyl peroxide were aggregated and used as the mass spectrometric information of the perfluoropolyether peroxide.

[0063] As a preferred embodiment of the method for determining the peroxide content in perfluoropolyethers according to the present invention, the specific steps of calculating the perfluoropolyether peroxide concentration based on the mass spectrometry information of the perfluoropolyether peroxide and outputting the peroxide content in the perfluoropolyether based on the perfluoropolyether peroxide concentration are as follows:

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

[0065]

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

[0067] The volume of perfluoropolyether peroxide (V) was diluted to the mark on the black glass bottle using solvent.

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

[0069] G = ∩·V

[0070] Where ∩ represents the concentration of perfluoropolyether peroxide, V represents the volume of perfluoropolyether peroxide in the black glass bottle, and G represents the peroxide content in the perfluoropolyether.

[0071] The concentration of perfluoropolyether peroxide (∩) was compared with the known concentration of the standard solution (C) to obtain the comparison results.

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

[0073] The concentration of perfluoropolyether peroxide (∩) was compared with the known concentration of the standard solution (C).

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

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

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

[0077] Thirdly, 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, it implements any step of the method for determining the peroxide content in perfluoropolyether as described in the first aspect of the present invention.

[0078] The beneficial effects of this invention are as follows: By selecting clean and dry sample vials and a high-precision electronic balance GS8202, accurate sample collection was achieved, improving the reliability of subsequent analytical results, reducing experimental errors, and ensuring the accuracy of the final determination results. Efficient pretreatment was achieved by using microwave-safe transparent glass vials and a polar-modified organic solvent methanol-water mixture, and by setting the microwave power and processing time, significantly shortening the extraction time and improving extraction efficiency. The introduction of a bifunctional probe solution and reaction under dark conditions enabled precise calculation of the reaction efficiency of the perfluoropolyether solution, improving the controllability and repeatability of the reaction and optimizing the reaction conditions through the reaction kinetic function. Effective separation of perfluoropolyether peroxides was achieved using an LC-MS instrument with a reversed-phase C18 column and gradient elution. Gradient elution significantly improved separation resolution and efficiency, ensuring effective separation of various components in complex samples and providing pure target compounds for subsequent mass spectrometry detection, thereby improving the accuracy of quantitative analysis. Attached Figure Description

[0079] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0081] Figure 2 This is a flowchart of the perfluoropolyether peroxide process in Example 1. Detailed Implementation

[0082] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0083] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the 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 phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

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

[0086] S1. Perfluoropolyether was collected by weighing using a balance to obtain a perfluoropolyether sample;

[0087] Furthermore, clean and dry sample vials and a high-precision electronic balance GS8202 are selected;

[0088] Place the sample vial on the GS8202 high-precision electronic balance and open the windproof cover of the GS8202 high-precision electronic balance;

[0089] Use a pipette to remove the perfluoropolyether from the container and add it to the sample vial to obtain a perfluoropolyether sample;

[0090] It should be noted that during the weighing process, all operations should be performed in a dust-free, low-humidity environment to prevent the sample from being contaminated or absorbing moisture. Using a high-precision electronic balance GS8202 can ensure the accuracy of the weighing. The use of a windproof cover can reduce the impact of airflow on the weighing results. The selection and calibration of the pipette are also crucial to ensure the accuracy of sample transfer.

[0091] S2. The perfluoropolyether sample was pretreated by microwave-assisted extraction technology to obtain a microwave-extracted perfluoropolyether solution.

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

[0093] Transfer the perfluoropolyether sample to a microwave-safe transparent glass bottle, and add a methanol-water mixture to the bottle.

[0094] The microwave-assisted extraction was performed in a microwave-assisted extraction instrument after adding the methanol-water mixture. The microwave power of the microwave-assisted extraction instrument was set to 800W and the processing time was set to 5 minutes.

[0095] After microwave-assisted extraction, the microwave-safe transparent glass bottle was removed and allowed to cool naturally to room temperature (25°C), yielding a microwave-extracted perfluoropolyether solution.

[0096] It should be noted that the microwave-safe transparent glass bottle was chosen to ensure that microwave energy can penetrate the sample uniformly and improve 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 extraction instrument was set to 800W and the processing time was set to 5 minutes to avoid decomposition or volatilization of the target compound due to overheating. Natural cooling to room temperature (25°C) can prevent the impact of sudden temperature changes on the stability of the solution.

[0097] S3. Add the bifunctional probe solution to the perfluoropolyether solution, and calculate the reaction efficiency of the perfluoropolyether solution under light-free conditions using a black glass bottle to obtain the perfluoropolyether reaction mixture.

[0098] Furthermore, a black glass bottle was chosen as the reaction vessel, and a microwave-extracted perfluoropolyether solution was added to the black glass bottle.

[0099] Add the bifunctional probe solution to a black glass bottle containing a microwave-extracted perfluoropolyether solution;

[0100] Place the black glass bottle containing the microwave-extracted perfluoropolyether solution and the bifunctional probe solution in a dark environment.

[0101] Based on the principle of reaction kinetics, the reaction temperature was set to 25℃ and the reaction time to 1 hour. During the reaction, a reaction kinetic function was introduced to calculate the reaction efficiency of the bifunctional probe solution and the microwave-extracted perfluoropolyether solution under different conditions. The expression is as follows:

[0102]

[0103] Where R is the reaction efficiency. denoted as , where 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 in the reaction process.

[0104] Based on the principles of reaction kinetics, a threshold W for reaction efficiency is set and compared with the reaction efficiency R.

[0105] When R < W, gradually increase the initial concentration H of the bifunctional probe solution 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, confirm that the binding between the bifunctional probe solution and the microwave-extracted perfluoropolyether peroxide meets the expected degree, and ensure that only perfluoropolyether peroxide is detected during the reaction process;

[0108] After the reaction was completed, the black glass bottle was removed from the dark environment, and a perfluoropolyether reaction mixture was obtained.

[0109] It should be noted that black glass bottles are used as reaction vessels to effectively prevent photosensitive reactions in the absence of light. The selection of bifunctional probe solutions should be based on their specific binding ability with the target compound to ensure that the reaction has high selectivity and sensitivity. Introducing a reaction kinetic function 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. The perfluoropolyether reaction mixture was separated by liquid chromatography-mass spectrometry to obtain the separated perfluoropolyether peroxide;

[0111] Furthermore, an LC-MS instrument was used, and a reversed-phase C18 column was 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] Formic acid, as a weak acid, can promote the deprotonation or hydrogenation ionization process in electrospray ionization (ESI). For perfluoropolyether peroxides, adding a small amount of formic acid helps to form stable [MH]- or [M+H]+ ions, thereby improving detection sensitivity.

[0114] Water is a polar solvent that can dissolve highly polar compounds. Adding formic acid not only improves the ionization efficiency but also enhances the solubility of perfluoropolyether peroxides. Acetonitrile is a commonly used nonpolar solvent that can effectively dissolve nonpolar or weakly polar compounds. Adding formic acid also helps to improve the ionization efficiency of perfluoropolyether peroxides.

[0115] The perfluoropolyether reaction mixture was injected into an LC-MS instrument, and the perfluoropolyether reaction mixture was separated in the LC-MS instrument using a gradient elution method;

[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 decreased. As the proportion of polar solvent phase A increases, different compounds will be gradually separated.

[0117] Low-polarity compounds are gradually eluted and separated in the initial stage of increasing proportion of polar solvent A phase;

[0118] The moderately polar compound was gradually eluted and separated as the proportion of the polar solvent A phase increased;

[0119] Highly polar compounds are eluted and separated in the later stages as the proportion of polar solvent A increases;

[0120] Finally, low-polarity, medium-polarity, and high-polarity compounds of perfluoropolyether were separated from the chromatographic column and labeled as perfluoropolyether peroxides.

[0121] It should be noted that the reversed-phase C18 column was chosen based on its excellent separation performance for nonpolar and moderately polar compounds. Gradient elution allows for stepwise separation based on the polarity differences of different compounds, ensuring high efficiency and resolution. By gradually increasing the proportion of the polar solvent A phase, compounds of different polarities can be eluted and separated sequentially, resulting in clear separation chromatograms. The final separated perfluoropolyether peroxide can be confirmed by retention time and mass-to-charge ratio (m / z), ensuring effective separation and identification of the target compound.

[0122] S5. The perfluoropolyether peroxide was ionized using an electrospray ionization source, and the characteristic ions of the perfluoropolyether peroxide were detected by a mass spectrometer to obtain the mass spectrometry information of the perfluoropolyether peroxide.

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

[0124] Charged ions were introduced into a triple quadrupole mass spectrometer (TQMS), and a positive and negative ion switching mode was set in the TQMS.

[0125] In positive ion mode, the triple quadrupole mass spectrometer (TQMS) is set to detect positively charged ions, detect compounds that form [M+H]+ ions among charged ions, and obtain the characteristic ion peak of [M+H]+ ions.

[0126] In negative ion mode, the triple quadrupole mass spectrometer (TQMS) is set to detect negatively charged ions and to detect compounds that form [MH]- anions among charged ions, thus obtaining the characteristic ion peaks in the form of [MH]- ions.

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

[0128] In the first-stage quadrupole Q1 of the triple quadrupole mass spectrometer (TQMS), with the molecular weight m set, the mass range of [M+H]+ ions is m+1, and the mass range of [MH]- ions is m-1. The parent ion-daughter ion pair is selected by the full scan method.

[0129] The selected mother ion-daughter ion pair undergoes collision-induced dissociation (CID) via the second-stage quadrupole Q2 of a triple quadrupole mass spectrometer (TQMS), and the collision energy is adjusted to cause the mother ion to fragment into fragment ions.

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

[0131] In the MassHunter software, input the characteristic ion and the corresponding mother ion-daughter ion pair;

[0132] Select perfluoroalkyl peroxide as a standard that has similar physicochemical properties to perfluoropolyether peroxide;

[0133] The concentration of the perfluoroalkyl peroxide solution was collected using an autosampler as a 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 the perfluoropolyether peroxide, and is marked as C. The solutions are injected sequentially from low concentration to high concentration.

[0136] During sample injection, data acquisition was initiated in MassHunter software to record the total ion chromatogram (TIC), extracted ion chromatogram (EIC), and mass spectrum for each injection of the perfluoroalkyl peroxide standard.

[0137] The retention times of the standard perfluoroalkyl peroxide were marked on the ion chromatogram EIC.

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

[0139] A standard curve was established using a linear regression algorithm to obtain the slope S and intercept I. The linear equation was then fitted using the least squares method to calculate the characteristic ion peak area A of the perfluoroalkyl peroxide standard. The expression is as follows:

[0140] A = S·C + I;

[0141] Where 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 mass-to-charge ratio of the parent ion-daughter ion pair, retention time, and characteristic ion peak area A of the standard perfluoroalkyl peroxide were aggregated and used as the mass spectrometry information of the perfluoropolyether peroxide.

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

[0144] S6. Based on the mass spectrometry information of perfluoropolyether peroxide, calculate the concentration of perfluoropolyether peroxide, and output the peroxide content in perfluoropolyether based on the concentration of perfluoropolyether peroxide.

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

[0146]

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

[0148] The volume of perfluoropolyether peroxide (V) was diluted to the mark on the black glass bottle using solvent.

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

[0150] G = ∩·V

[0151] Where ∩ represents the concentration of perfluoropolyether peroxide, V represents the volume of perfluoropolyether peroxide in the black glass bottle, and G represents the peroxide content in the perfluoropolyether.

[0152] The concentration of perfluoropolyether peroxide (∩) was compared with the known concentration of the standard solution (C) to obtain the comparison results.

[0153] The concentration of perfluoropolyether peroxide (∩) was compared with the known concentration of the standard solution (C).

[0154] When the peroxide concentration ∩ of perfluoropolyether 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 indicates 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-value of the standard curve. 2 Value, ensure it is close to Then, the slope S and intercept I of the standard curve are substituted back into the concentration calculation expression for calculation until ∩≤C;

[0156] It should be noted that when calculating the concentration of perfluoropolyether peroxides based on mass spectrometry information, it is essential to ensure that the slope and intercept of the standard curve used are derived from reliable linear regression analysis, and that R0 is accurate. 2 A value close to 1 indicates a good linear relationship. When calculating the peroxide content in perfluoropolyether, the total volume or total mass of the sample needs to be specified 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 the peroxide concentration of perfluoropolyether is found to be outside the expected range, the experimental conditions and the establishment process of the standard curve should be carefully checked to ensure that all parameters meet the requirements. If necessary, the experiment should be repeated to obtain more accurate results.

[0157] This embodiment also provides a computer device applicable to the method for determining the peroxide content in perfluoropolyether, comprising: 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 realize the method for determining the peroxide content in perfluoropolyether as proposed in the above embodiment.

[0158] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0159] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the method for determining the peroxide content in perfluoropolyether as described in the above embodiments. 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 (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0160] In summary, this invention achieves precise sample collection by selecting clean and dry sample vials and a high-precision electronic balance GS8202, improving the reliability of subsequent analytical results, reducing experimental errors, and ensuring the accuracy of the final determination results. By using microwave-safe transparent glass vials and a polar-modified organic solvent methanol-water mixture, and by setting the microwave power and processing time, efficient pretreatment is achieved, significantly shortening the extraction time and improving extraction efficiency. By introducing a bifunctional probe solution and reacting in a dark environment, the reaction efficiency of the perfluoropolyether solution is accurately calculated, improving the controllability and repeatability of the reaction and optimizing the reaction conditions through the reaction kinetic function. Using an LC-MS instrument with a reversed-phase C18 column and gradient elution, effective separation of perfluoropolyether peroxides is achieved. Gradient elution significantly improves separation resolution and efficiency, ensuring the effective separation of various components in complex samples and providing 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 and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for determining the peroxide content in perfluoropolyether, characterized in that: include: Perfluoropolyether was collected by weighing using a balance to obtain perfluoropolyether samples; The perfluoropolyether sample was pretreated using microwave-assisted extraction technology to obtain a microwave-extracted perfluoropolyether solution. The specific steps are as follows: Microwave-safe transparent glass bottles were selected as microwave-assisted extraction containers, and a mixture of methanol and water with polar modified organic solvent was prepared. Transfer the perfluoropolyether sample to a microwave-safe transparent glass bottle, and add a methanol-water mixture to the bottle. The microwave-assisted extraction was carried out in a microwave-assisted extraction instrument after adding the methanol-water mixture. The microwave power and processing time of the microwave-assisted extraction instrument were set. After microwave-assisted extraction, the microwave-safe transparent glass bottle was removed and allowed to cool naturally to room temperature, yielding a microwave-extracted perfluoropolyether solution. The bifunctional probe solution was added to the perfluoropolyether solution, and the reaction efficiency of the perfluoropolyether solution was calculated under dark conditions using a black glass bottle to obtain the perfluoropolyether reaction mixture. The specific steps are as follows: A black glass bottle was selected as the reaction vessel, and a perfluoropolyether solution extracted by microwave was added to the black glass bottle. Add the bifunctional probe solution to a black glass bottle containing a microwave-extracted perfluoropolyether solution; Place the black glass bottle containing the microwave-extracted perfluoropolyether solution and the bifunctional probe solution in a dark environment. The reaction temperature and reaction time were set, and a reaction kinetic function was introduced during the reaction process. The reaction efficiency of the bifunctional probe solution and the microwave-extracted perfluoropolyether solution under different conditions was calculated, and the expression is: ； in, For reaction efficiency, The binding concentration of the probe solution after the reaction. The concentration of the bifunctional probe solution. The binding rate constant, For reaction time, It is a time constant. It is an exponential function in the reaction process; Set a threshold for reaction efficiency With reaction efficiency Perform a comparison; when < At the same time, gradually increase the initial concentration of the bifunctional probe solution. until ≥ ; when ≥ At the same time, it was confirmed that the binding between the bifunctional probe solution and the microwave-extracted perfluoropolyether peroxide met the expected degree, and it was ensured that only perfluoropolyether peroxide was detected during the reaction process; After the reaction was completed, the black glass bottle was removed from the dark environment, and a perfluoropolyether reaction mixture was obtained. The perfluoropolyether reaction mixture was separated by liquid chromatography-mass spectrometry to obtain the separated perfluoropolyether peroxide; Perfluoropolyether peroxide was ionized using an electrospray ionization source, and its characteristic ions were detected by mass spectrometry to obtain its mass spectrometric information. Based on the mass spectrometry information of perfluoropolyether peroxides, the concentration of perfluoropolyether peroxides is calculated, and the peroxide content in perfluoropolyether is output based on the concentration of perfluoropolyether peroxides.

2. The method for determining the peroxide content in perfluoropolyether as described in claim 1, characterized in that: The perfluoropolyether was collected using a balance weighing method to obtain a perfluoropolyether sample. The specific steps are as follows: Choose clean and dry sample vials and a high-precision electronic balance GS8202; Place the sample vial on the GS8202 high-precision electronic balance and open the windproof cover of the GS8202 high-precision electronic balance; Use a pipette to remove the perfluoropolyether from the container and add it to the sample vial to obtain a perfluoropolyether sample.

3. The method for determining the peroxide content in perfluoropolyether as described in claim 1, characterized in that: The perfluoropolyether reaction mixture is separated using liquid chromatography-mass spectrometry to obtain the separated perfluoropolyether peroxide. The specific steps are as follows: LC-MS instrument was used, and a reversed-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; The perfluoropolyether reaction mixture was injected into an LC-MS instrument, and the perfluoropolyether reaction mixture was separated in the LC-MS instrument using a gradient elution method; 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 decreased. As the proportion of polar solvent phase A increases, different compounds will be gradually separated. Low-polarity compounds are gradually eluted and separated in the initial stage of increasing proportion of polar solvent A phase; The moderately polar compound was gradually eluted and separated as the proportion of the polar solvent A phase increased; Highly polar compounds are eluted and separated in the later stages as the proportion of polar solvent A increases; Finally, low-polarity, medium-polarity, and high-polarity compounds of perfluoropolyether were separated from the chromatographic column and labeled as perfluoropolyether peroxides.

4. The method for determining the peroxide content in perfluoropolyether as described in claim 3, characterized in that: The process involves ionizing perfluoropolyether peroxide using an electrospray ionization source and detecting its characteristic ions using a mass spectrometer to obtain its mass spectrometric information. The specific steps are as follows: The perfluoropolyether peroxide, after gradient elution separation, is introduced into the electrospray ionization source ESI and evaporated to form charged ions. Charged ions were introduced into a triple quadrupole mass spectrometer (TQMS), and a positive and negative ion switching mode was set in the TQMS. In positive ion mode, the triple quadrupole mass spectrometer (TQMS) is set to detect positively charged ions, detect compounds that form [M+H]+ ions among charged ions, and obtain the characteristic ion peak of [M+H]+ ions. In negative ion mode, the triple quadrupole mass spectrometer (TQMS) is set to detect negatively charged ions and to detect compounds that form [MH]- anions among charged ions, thus obtaining the characteristic ion peaks in the form of [MH]- ions. In the triple quadrupole mass spectrometer (TQMS), the parent ions are summarized using the multiple reaction monitoring (MRM) mode based on the characteristic ion peaks in the form of [M+H]+ ions and [MH]- ions. In the first-stage quadrupole Q1 of the triple quadrupole mass spectrometer (TQMS), with the molecular weight m set, the mass range of [M+H]+ ions is m+1, and the mass range of [MH]- ions is m-1. The parent ion-daughter ion pair is selected by the full scan method. The selected mother ion-daughter ion pair undergoes collision-induced dissociation (CID) via the second-stage quadrupole Q2 of a triple quadrupole mass spectrometer (TQMS), and the collision energy is adjusted to cause the mother ion to fragment into fragment ions. In the third quadrupole Q3 of the triple quadrupole mass spectrometer (TQMS), fragment ions generated by collision-induced dissociation (CID) are used as characteristic ions. In the MassHunter software, input the characteristic ion and the corresponding mother ion-daughter ion pair; Select perfluoroalkyl peroxide as a standard that has similar physicochemical properties to perfluoropolyether peroxide; The concentration of the perfluoroalkyl peroxide solution was collected using an autosampler as a known standard concentration. The expected concentration range of perfluoropolyether peroxide is set as follows: ; The concentration of the standard perfluoroalkyl peroxide solution covers the expected concentration range of the perfluoropolyether peroxide. Marked as Samples were injected sequentially from low to high concentration. During sample injection, data acquisition was initiated in MassHunter software to record the total ion chromatogram (TIC), extracted ion chromatogram (EIC), and mass spectrum for each injection of the perfluoroalkyl peroxide standard. The retention times of the standard perfluoroalkyl peroxide were marked on the ion chromatogram EIC. In the mass spectrum, record the mass-to-charge ratio of the parent ion to the daughter ion of the standard perfluoroalkyl peroxide; A standard curve is established using a linear regression algorithm, and the slope of the standard curve is obtained. and intercept The least squares method was used to fit the linear equation, and the characteristic ion peak area of ​​the standard perfluoroalkyl peroxide was calculated. The expression is: ； in, The peak area of ​​the characteristic ion of the standard perfluoroalkyl peroxide is given. The slope of the standard curve. As a correction factor, The intercept is... The concentration of the standard perfluoroalkyl peroxide solution; The mass-to-charge ratio, retention time, and characteristic ion peak area of ​​the standard perfluoroalkyl peroxide were determined. The data were collected and used as mass spectrometry information for perfluoropolyether peroxides.

5. The method for determining the peroxide content in perfluoropolyether as described in claim 4, characterized in that: The specific steps for calculating the perfluoropolyether peroxide concentration based on the mass spectrometry information of the perfluoropolyether peroxide and outputting the peroxide content in the perfluoropolyether based on the perfluoropolyether peroxide concentration are as follows: Based on the parent-daughter ion mass-to-charge ratio, retention time, and characteristic ion peak area of ​​standard perfluoroalkyl peroxide. The peroxide concentration of perfluoropolyether is calculated using the following expression: ； in, This refers to the concentration of perfluoropolyether peroxide. The peak area represents the characteristic ion peak. The slope of the standard curve. As a correction factor, The intercept; The volume was adjusted to the mark on the black glass bottle using solvent, and the volume was marked as perfluoropolyether peroxide. ; Based on the volume of perfluoropolyether peroxide and perfluoropolyether peroxide concentration Calculate the peroxide content in perfluoropolyether. The expression is: ； in, This refers to the concentration of perfluoropolyether peroxide. This represents the volume of perfluoropolyether peroxide in the black glass bottle. This refers to the peroxide content in perfluoropolyethers; Perfluoropolyether peroxide concentration With known standard solution concentration The comparison was performed, and the comparison results were obtained.

6. The method for determining the peroxide content in perfluoropolyether as described in claim 5, characterized in that: The specific steps for comparing the concentration of perfluoropolyether peroxide with the concentration of a known standard solution to obtain the comparison result are as follows: When the perfluorinated polyether peroxide concentration At the known standard solution concentration If the result is within the range, it indicates that the peroxide content in the perfluoropolyether sample meets expectations and is marked as the quantitative result of perfluoropolyether peroxide. When the peroxide concentration of perfluoropolyether exceeds the known concentration of the standard solution > When the peroxide content in the perfluoropolyether is too high, it indicates that the peroxide content in the perfluoropolyether sample is reduced, and the slope of the standard curve is adjusted again. and intercept Substitute the values ​​into the concentration calculation expression and perform the calculation until... .

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the method for determining the peroxide content in perfluoropolyether according to any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the method for determining the peroxide content in perfluoropolyether according to any one of claims 1 to 6.

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