Method for determining content of o-phenylenediamine and 2-methylbenzimidazole

Abstract

The invention provides a method for measuring the content of o-phenylenediamine and 2-methylbenzimidazole, which comprises the following steps of: optimizing an MRM method based on a GC-QQQ optimizer to obtain an MRM optimization method; the method comprises the following steps: detecting o-phenylenediamine and 2-methylbenzimidazole mixed standard solutions with different concentration gradients based on an MRM optimization method to obtain a characteristic ion flow peak area of each compound and a concentration linear regression equation of each compound, and taking the concentration linear regression equation as a quantitative standard curve equation of each compound; extracting a to-be-detected sample into the organic phase in a rapid solvent extractor, separating out suspended catalyst particles in the raw material, and extracting organic components on the surface of the catalyst and in pores into the organic phase to obtain a to-be-detected organic phase; detecting a to-be-detected organic phase by using an MRM optimization method to obtain a corresponding characteristic peak of the to-be-detected organic phase; and according to the peak area of the characteristic peak of each compound of the to-be-detected organic phase, based on the quantitative standard curve equation, obtaining the content of each compound in the to-be-detected sample.

Description

Technical Field

[0001] The invention belongs to the field of energy chemical industry and analysis technology, and specifically belongs to a method for determining the contents of o-phenylenediamine and 2-methylbenzimidazole. Background Art

[0002] Photocatalytic hydrogen production coupled with organic synthesis has the advantages of mild reaction conditions, high value of oxidation products, and easy separation of products. Compared with the traditional photocatalytic water decomposition reaction, the use of suitable organic oxidation reactions to replace the four-electron oxygen evolution reaction or the consumption of hole sacrificial agents, paired with the photocatalytic hydrogen evolution reaction, can make full use of photogenerated holes and electrons, and avoid the safety hazards caused by the mixing of oxygen and hydrogen produced by photocatalytic water decomposition. At the same time, clean fuel hydrogen and high-value chemicals are produced. The synthesized organic compounds have higher economic value than oxygen, which improves the overall economic benefits of photocatalytic hydrogen production.

[0003] Benzimidazole compounds are widely present in drugs and are often used to treat infections. Traditional methods for synthesizing benzimidazole drugs often couple aromatic amines with carboxylic acids or their derivatives with strong acids under high temperature conditions or condense o-phenylenediamine with aldehydes, but these methods require stoichiometric or excessive amounts of strong oxidants (such as potassium persulfate, dichlorodicyanobenzoquinone, etc.). At the same time, the use of these methods to synthesize benzimidazole compounds will produce a large number of by-products and consume a lot of energy. The solar photocatalytic synthesis of benzimidazole drugs can be carried out under mild reaction conditions and avoids the shortcomings of the traditional benzimidazole synthesis method, such as harsh reaction conditions, huge energy consumption, and poor product selectivity.

[0004] Photocatalytic hydrogen production coupled with 2-methylbenzimidazole synthesis is a technology with great development prospects. The raw material used in the synthesis is an ethanol solution of o-phenylenediamine. Therefore, it is particularly important to detect the content of o-phenylenediamine and 2-methylbenzimidazole before and after the synthesis. However, the existing related technologies lack a perfect method to accurately analyze the content of phenolic organic matter in waste before and after treatment, so as to evaluate the effect of the synthesis. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a method for determining the content of o-phenylenediamine and 2-methylbenzimidazole, so as to solve the problem that the prior art lacks a method for accurately analyzing the content of phenolic organic matter in waste before and after treatment.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole comprises the following steps: The MRM method was optimized based on the GC-QQQ optimizer, and the MRM optimization method suitable for o-phenylenediamine and 2-methylbenzimidazole was obtained; Based on the MRM optimization method, the mixed standard solutions of o-phenylenediamine and 2-methylbenzimidazole with different concentration gradients were detected to obtain the linear regression equation between the characteristic ion current peak area of ​​each compound and the concentration of each compound, and the concentration linear regression equation was used as the quantitative standard curve equation of each compound; The sample to be tested is extracted into an organic phase in a rapid solvent extractor, and the catalyst particles suspended in the raw material are separated to obtain an organic phase to be tested; The organic phase to be tested is detected using the MRM optimization method to obtain the corresponding characteristic peak of the organic phase to be tested; According to the peak area of ​​the characteristic peak of each compound in the organic phase to be tested, based on the quantitative standard curve equation, the specific content of each compound in the sample to be tested is obtained.

[0007] Further, the process of optimizing the MRM method based on the GC-QQQ optimizer to obtain the MRM optimization method suitable for o-phenylenediamine and 2-methylbenzimidazole is: The precursor ions are fragmented at different collision energies, and the product ions with higher responses are selected; Selecting the ion pair with the highest response among the product ions with higher response as the quantitative ion pair; Two additional pairs of qualifier ion pairs were selected for each compound, the responses of which were just below the highest responding ion pair.

[0008] Further, based on the collision energy corresponding to the quantitative ion pair and the qualitative ion, the collision energy is optimized to obtain the collision energy with the highest response; When optimizing the collision energy, the collision energy is increased and decreased in equal proportion, and the collision energy with the highest response and the most optimized collision energy is selected under the increased and decreased collision energies.

[0009] Further, the mixed standard solutions of o-phenylenediamine and 2-methylbenzimidazole with different concentration gradients are: The concentrations of o-phenylenediamine and 2-methylbenzimidazole are 10 μg / mL, 20 μg / mL, 30 μg / mL, 40 μg / mL and 50 μg / mL of mixed standard solutions.

[0010] Furthermore, the detection conditions in the MRM optimization method are: Chromatographic column: Agilent J&W HP-5, 30m; Carrier gas: helium, purity ≥ 99.999%.

[0011] Furthermore, the instruments and equipment used in the MRM optimization method detection are: Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer, Dionex ASE 350 rapid solvent extractor and Gilson ASPEC XL liquid handling system.

[0012] Furthermore, the column box heating steps of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer are as follows: 80℃ for 2min; Raise the temperature to 240°C at 8°C / min and hold for 2 min; Raise the temperature to 280°C at 8°C / min and hold for 2 min; The post-operation temperature of the column box was 300° C., and backflushing was performed for 1.5 min.

[0013] Furthermore, the carrier gas of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is helium, and the purity of the helium is ≥99.999%; The injection port temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer was 280° C. and the injection volume was 1 μL; The injection method is splitless injection; The electron bombardment source of the Agilent 8890-7000D gas chromatograph coupled to a triple quadrupole mass spectrometer is 70 eV; The ion source temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is 280°C; The transmission line temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is 280°C; The solvent delay of the Agilent 8890-7000D gas chromatograph coupled to a triple quadrupole mass spectrometer was 5 min.

[0014] Furthermore, the extraction process uses a rapid solvent extractor, and the extraction solvent used by the rapid solvent extractor is methanol.

[0015] Furthermore, the temperature during the extraction is 75-100° C., the pressure is 1500 psi, the heating time is 5 min, the static time is 5 min, the flushing volume is 60%, the purge time is 100 seconds; and the number of cycles is 1.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The invention provides a method for determining the content of o-phenylenediamine and 2-methylbenzimidazole, comprising the following steps: optimizing an MRM method based on a GC-QQQ optimizer to obtain an MRM optimization method suitable for o-phenylenediamine and 2-methylbenzimidazole; detecting mixed standard solutions of o-phenylenediamine and 2-methylbenzimidazole with different concentration gradients based on the MRM optimization method to obtain a linear regression equation between the characteristic ion flow peak area of ​​each compound and the concentration of each compound, and using the concentration linear regression equation as a quantitative standard curve equation for each compound; extracting a sample to be tested into an organic phase in a rapid solvent extractor to separate catalyst particles suspended in the raw material, and The organic components on the catalyst surface and inside the pores are also extracted into the organic phase to obtain the organic phase to be tested; the organic phase to be tested is detected using the MRM optimization method to obtain the corresponding characteristic peaks of the organic phase to be tested; according to the peak area of ​​the characteristic peak of each compound in the organic phase to be tested, based on the quantitative standard curve equation, the content of each specific compound in the sample to be tested is obtained; the present application can completely separate the o-phenylenediamine and 2-methylbenzimidazole organic matter in the sample to be tested from other compounds with the same or similar retention time in the gas chromatography, and remove the influence of background and impurities, so as to obtain more accurate o-phenylenediamine and 2-methylbenzimidazole organic matter for qualitative and quantitative analysis.

[0017] Furthermore, this method uses the GC-QQQ optimizer to fine-tune the MRM (multiple reaction monitoring) method, and shows significant advantages and benefits for the quantitative analysis of o-phenylenediamine and 2-methylbenzimidazole. This method effectively promotes the fragmentation of the precursor ion by precisely adjusting the collision energy, thereby screening out product ions with high responsiveness, greatly improving the sensitivity and accuracy of the detection, and selecting the ion pair with the highest responsiveness as the quantitative benchmark to ensure the reliability and repeatability of the quantitative results, providing solid data support for quality control in scientific research and production. In order to increase the comprehensiveness and robustness of the analysis, two pairs of qualitative ion pairs are additionally selected for each target compound. The response of these ion pairs is second only to the quantitative ion pairs. As auxiliary verification means, they effectively reduce the risk of misjudgment and improve the confidence of the detection results.

[0018] Furthermore, this method carefully optimizes the collision energy corresponding to the quantitative ion pairs and the qualitative ion pairs, and uses the method of equal-interval increase and decrease to explore the optimal collision energy, thereby ensuring the maximization of ion fragmentation and signal response during the detection process. This not only simplifies the operating process, but also significantly improves the accuracy and efficiency of detection. The optimized collision energy enables the ions to produce more and more stable product ions during the fragmentation process, thereby enhancing the strength and stability of the signal.

[0019] Furthermore, this method uses mixed standard solutions of o-phenylenediamine and 2-methylbenzimidazole with multiple concentration gradients (10μg / mL to 50μg / mL) to construct a comprehensive analytical calibration curve, which not only improves the accuracy and linear range of quantitative analysis, but also enhances the applicability and reliability of the method. By accurately measuring the response signals at different concentrations, it can more accurately evaluate the relationship between the instrument response and the concentration of the analyte, thereby optimizing the quantitative analysis conditions.

[0020] Furthermore, this method uses Agilent 8890-7000D GC-QQQ MS / MS to ensure the accurate identification and quantitative analysis of target compounds in complex matrices, improve selectivity and specificity, and make the detection results more reliable; the Dionex ASE 350 rapid solvent extractor is used to significantly shorten the sample preparation time and reduce human errors, ensuring the consistency and efficiency of sample extraction; the Gilson ASPEC XL liquid handling system is used to provide reliable support for the solution preparation, dilution and transfer steps in the entire detection process, further improving the accuracy and repeatability of the experiment.

[0021] Furthermore, this method effectively improves the separation effect and detection sensitivity of the target compounds o-phenylenediamine and 2-methylbenzimidazole by finely controlling the temperature change. It starts with an initial preheating of 80°C to ensure that the sample is fully vaporized and initially separated, and then gradually heats up to 240°C and 280°C at a rate of 8°C / min, which promotes the effective separation of compounds with different boiling points, avoids peak overlap, and improves the clarity and resolution of the chromatogram. The post-operation temperature is set to 300°C and backflushed for 1.5 minutes to further remove residues, ensure the cleanliness of the chromatographic column and the accuracy of subsequent analysis. This heating program not only optimizes the analysis time, but also significantly enhances the reliability and repeatability of the analysis results.

[0022] Furthermore, this method uses high-purity (≥99.999%) helium as the carrier gas, ensuring the stability and reliability of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer during the analysis process, effectively reducing background noise and impurity interference, setting the injection port temperature to 280°C, ensuring rapid vaporization of the sample, avoiding sample loss, and improving the sensitivity of the analysis. The selection of an electron bombardment source of 70eV provides the same ionization energy as the NIST library, promotes the effective fragmentation and ionization of the target compound, and also makes the mass spectrum of the target compound easy to match and identify. The ion source temperature and the transmission line temperature are both set to 280°C, ensuring the efficiency and stability of ion transmission. The 5-min solvent delay effectively removes the interference of the solvent peak on the analysis of the target compound, further improving the accuracy and reliability of the analysis results.

[0023] Furthermore, the method uses a rapid solvent extractor with methanol as the extraction solvent, combined with optimized extraction conditions (temperature 75-100°C, pressure 1500psi, heating time 5min, static time 5min, flushing volume 60%, purge time 100s, cycle 1), which significantly improves the extraction efficiency and recovery rate of o-phenylenediamine and 2-methylbenzimidazole, shortens the extraction time, and the optimized conditions ensure the stability and repeatability of the extraction process, effectively avoiding the degradation or loss of the target compound. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the total ion current diagram of the MRM analysis method of the 50 μg / mL standard solution of the embodiment disclosed in the present invention; Figure 2 It is a standard curve diagram of quantitative analysis of o-phenylenediamine according to the disclosed embodiment of the present invention; Figure 3 The standard curve diagram of quantitative analysis of 2-methylbenzimidazole of the disclosed embodiment of the present invention; Figure 4 It is a total ion current diagram of the MRM test method of the sample 1 to be tested according to the embodiment disclosed in the present invention; Figure 5 This is the total ion current diagram of the MRM test method of the sample 2 to be tested according to the embodiment disclosed in the present invention. DETAILED DESCRIPTION

[0025] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0028] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0029] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0030] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0031] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0032] The present disclosure provides a method for determining the content of o-phenylenediamine and 2-methylbenzimidazole, comprising the following steps: The MRM method was optimized based on the GC-QQQ optimizer, and the MRM optimization method suitable for o-phenylenediamine and 2-methylbenzimidazole was obtained; Based on the MRM optimization method, the mixed standard solutions of o-phenylenediamine and 2-methylbenzimidazole with different concentration gradients were detected to obtain the linear regression equation between the characteristic ion current peak area of ​​each compound and the concentration of each compound, and the concentration linear regression equation was used as the quantitative standard curve equation of each compound; The sample to be tested is extracted into an organic phase in a rapid solvent extractor, the catalyst particles suspended in the raw material are separated, and the organic components on the surface and inside the pores of the catalyst are also extracted into the organic phase to obtain an organic phase to be tested; The organic phase to be tested is detected using the MRM optimization method to obtain the corresponding characteristic peak of the organic phase to be tested; According to the peak area of ​​the characteristic peak of each compound in the organic phase to be tested, based on the quantitative standard curve equation, the content of each specific compound in the sample to be tested is obtained.

[0033] Preferably, in the disclosed embodiment, the process of optimizing the MRM method based on the GC-QQQ optimizer to obtain the MRM optimization method suitable for o-phenylenediamine and 2-methylbenzimidazole is: The precursor ions are fragmented at different collision energies, and the product ions with higher responses are selected; Selecting the ion pair with the highest response among the product ions with higher response as the quantitative ion pair; Two additional pairs of qualifier ion pairs were selected for each compound, the responses of which were just below the highest responding ion pair.

[0034] Further, based on the collision energy corresponding to the quantitative ion pair and the qualitative ion, the collision energy is optimized to obtain the collision energy with the highest response; When optimizing the collision energy, the collision energy is increased and decreased in equal proportion, and the collision energy with the highest response and the most optimized collision energy is selected under the increased and decreased collision energies.

[0035] Preferably, in the disclosed embodiment, the mixed standard solution of o-phenylenediamine and 2-methylbenzimidazole with different concentration gradients is: The concentrations of o-phenylenediamine and 2-methylbenzimidazole are 10 μg / mL, 20 μg / mL, 30 μg / mL, 40 μg / mL and 50 μg / mL of mixed standard solutions.

[0036] It should be noted that o-phenylenediamine and 2-methylbenzimidazole were accurately weighed and dissolved in methanol solvent to prepare a mixed standard solution stock solution with the same concentration of each compound and 1000 μg / mL, and then diluted to mixed standard solutions with concentrations of 10μg / mL, 20μg / mL, 30μg / mL, 40μg / mL and 50μg / mL. The standard solution was prepared and used immediately, and was usually sealed and stored at -20℃;.

[0037] Preferably, in the disclosed embodiment, the detection conditions in the MRM optimization method are: Chromatographic column: Agilent J&W HP-5, 30m; Carrier gas: helium, purity ≥ 99.999%.

[0038] Specifically, the instruments and equipment used in the MRM optimization method detection are: Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer, Dionex ASE 350 rapid solvent extractor and Gilson ASPEC XL liquid handling system.

[0039] Specifically, Further, in the disclosed embodiment, the column box heating step of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is: 80℃ for 2min; Raise the temperature to 240°C at 8°C / min and hold for 2 min; Raise the temperature to 280°C at 8°C / min and hold for 2 min; The post-operation temperature of the column box was 300° C., and backflushing was performed for 1.5 min.

[0040] It should be noted that the post-operation means that the column box maintains the temperature at 300° C. in order to prepare for the next analysis or protect the chromatographic column.

[0041] Furthermore, the carrier gas of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is helium, and the purity of the helium is ≥99.999%; The injection port temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer was 280° C. and the injection volume was 1 μL; The injection method is splitless injection; The electron bombardment source of the Agilent 8890-7000D gas chromatograph coupled to a triple quadrupole mass spectrometer is 70 eV; The ion source temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is 280°C; The transmission line temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is 280°C; The solvent delay of the Agilent 8890-7000D gas chromatograph coupled to a triple quadrupole mass spectrometer was 5 min.

[0042] Preferably, in the embodiment of the present disclosure, the extraction process uses a rapid solvent extractor, and the extraction solvent used by the rapid solvent extractor is methanol; the solvent extractor obtains the organic phase to be tested based on high performance liquid chromatography extraction; specifically, the temperature during the extraction is 75-100°C, the pressure is 1500psi, the heating time is 5min, the static time is 5min, the flushing volume is 60%, and the purge time is 100 seconds; the number of cycles is 1 time.

[0043] Table 1 shows the temperature effect of extracting petroleum hydrocarbons from soil in the embodiment of the present disclosure. Increasing the temperature not only increases the extraction recovery rate, but also improves the repeatability of the extraction. When the temperature is 75-100°C, the extraction recovery rate is about 100%, and the relative standard deviation is small, which meets the requirements of the present invention.

[0044] Table 1 Effect of extraction temperature on the recovery rate of petroleum hydrocarbons extracted from soil

[0045] Example: Determine instrument analysis conditions, including chromatographic conditions and mass spectrometry conditions: Chromatographic column: Agilent J&W HP-5, 30m; Column box heating program: 80℃ for 2 minutes, then increase the temperature to 240℃ at 8℃ / min, and maintain for 2 minutes; then increase the temperature to 280℃ at 8℃ / min, and maintain for 2 minutes; then run 300℃ backflush for 1.5 minutes; Carrier gas: helium, purity ≥99.999%; injection port temperature: 280℃; injection volume: 1μL; injection mode: splitless injection; electron bombardment source: 70eV; ion source temperature: 280℃; transfer line temperature: 280℃; solvent delay: 5min; The detection results of each compound in the 50 μg / mL standard solution obtained according to the analytical conditions are shown in Table 1.

[0046] Table 1 Organic substances detected in standard solutions and their retention times

[0047] First, select the precursor ions with higher response and larger mass number; then fragment the precursor ions at different collision energies (5, 15, 25, 35) and select the product ions with higher response. The ion pairs with the highest response are used as quantitative ion pairs, and two pairs of qualitative ion pairs are selected for each compound; finally, optimize the collision energy to obtain the collision energy with the highest response, thus obtaining a complete MRM optimization method.

[0048] The total ion chromatogram of the 50 μg / mL standard solution obtained according to the established MRM optimization method is shown in Figure 1 shown.

[0049] Table 2 Ion pairs and collision energy results selected for the established MRM analysis method

[0050] Establishment of quantitative method: The prepared mixed standard solutions of o-phenylenediamine and 2-methylbenzimidazole with concentrations of 10 μg / mL, 20 μg / mL, 30 μg / mL, 40 μg / mL and 50 μg / mL were detected using the MRM optimization method to obtain the linear regression equation of the characteristic ion current peak area y of each compound and its concentration x (μg / mL), and the standard curve equation and its linear correlation coefficient R2 were obtained; The obtained standard curves of o-phenylenediamine and 2-methylbenzimidazole are as follows: Figure 2-3 The linear regression equations of the compounds are shown in Table 3: Table 3 Linear regression equation results of each compound

[0051] Testing of actual samples: Samples 1 and 2 synthesized with different catalysts were subjected to sample pretreatment, respectively, and detected using the established MRM method, and characteristic peaks corresponding to the detected compounds were obtained through quantitative and qualitative ion pairs; The total ion currents of samples 1 and 2 measured according to the MRM optimization method are as follows: Figure 4-5 shown.

[0052] The test results are then used in the quantitative standard curve equation, and the content of each specific compound in the sample to be tested is obtained based on the characteristic ion current peak area of ​​each compound and the quantitative standard curve equation.

[0053] Table 4 Detection results of each compound in sample 1

[0054] Table 5 Detection results of each compound in sample 2

[0055] Table 6 Qualitative results of compounds detected in sample 1

[0056] Table 7 Qualitative results of compounds detected in sample 2

[0057] The retention time of the detected compound in the sample to be tested is very close to the retention time of the corresponding compound in the standard solution, and the accuracy of the two pairs of qualifier ions is about 100%, indicating that the qualitative results of the detected compounds are accurate and reliable. The retention time of the undetected compound in the sample to be tested does not match the retention time of the corresponding compound in the standard solution, and the two pairs of qualifier ions are not found, indicating that the sample does not contain the compound.

[0058] The MRM (Multiple Reaction Monitoring) method in the present invention is a mass spectrometry technique, which is mainly used for qualitative and quantitative analysis of target compounds. This technique achieves high sensitivity and high selectivity detection of specific compounds by selectively monitoring the conversion of pre-set parent ions to daughter ions. In the analysis of complex samples, the MRM method is particularly effective because it can filter out interfering signals and focus on the signal measurement of the molecules to be tested, making the quantitative analysis more accurate.

[0059] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0060] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for determining the content of o-phenylenediamine and 2-methylbenzimidazole, characterized in that: The following steps are involved: The MRM method was optimized based on the GC-QQQ optimizer, and the MRM optimization method suitable for o-phenylenediamine and 2-methylbenzimidazole was obtained; Based on the MRM optimization method, the mixed standard solutions of o-phenylenediamine and 2-methylbenzimidazole with different concentration gradients were detected to obtain the linear regression equation between the characteristic ion current peak area of ​​each compound and the concentration of each compound, and the concentration linear regression equation was used as the quantitative standard curve equation of each compound; The sample to be tested is extracted into an organic phase in a rapid solvent extractor, and the catalyst particles suspended in the raw material are separated to obtain an organic phase to be tested; The organic phase to be tested is detected using the MRM optimization method to obtain the corresponding characteristic peak of the organic phase to be tested; According to the peak area of ​​the characteristic peak of each compound in the organic phase to be tested, based on the quantitative standard curve equation, the specific content of each compound in the sample to be tested is obtained.

2. The method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 1, characterized in that: The process of optimizing the MRM method based on the GC-QQQ optimizer to obtain the MRM optimization method suitable for o-phenylenediamine and 2-methylbenzimidazole is as follows: The precursor ions are fragmented at different collision energies, and the product ions with higher responses are selected; Selecting the ion pair with the highest response among the product ions with higher response as the quantitative ion pair; Two additional pairs of qualifier ion pairs were selected for each compound, the responses of which were just below the highest responding ion pair.

3. The method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 2, characterized in that: Based on the collision energies corresponding to the quantitative ion pair and the qualitative ion, the collision energy is optimized to obtain the collision energy with the highest response; When optimizing the collision energy, the collision energy is increased and decreased in equal proportion, and the collision energy with the highest response and the most optimized collision energy is selected under the increased and decreased collision energies.

4. The method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 1, characterized in that: The mixed standard solutions of o-phenylenediamine and 2-methylbenzimidazole with different concentration gradients are: The concentrations of o-phenylenediamine and 2-methylbenzimidazole are 10 μg / mL, 20 μg / mL, 30 μg / mL, 40 μg / mL and 50 μg / mL of mixed standard solutions.

5. The method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 1, characterized in that: The detection conditions in the MRM optimization method are: Chromatographic column: Agilent J&W HP-5, 30m; Carrier gas: helium, purity ≥ 99.999%.

6. The method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 2, characterized in that: The instruments and equipment used in the MRM optimization method detection are: Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer, Dionex ASE 350 rapid solvent extractor and Gilson ASPEC XL liquid handling system.

7. The method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 6, characterized in that: The column box heating steps of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer are as follows: 80℃ for 2min; Raise the temperature to 240°C at 8°C / min and hold for 2 min; Raise the temperature to 280°C at 8°C / min and hold for 2 min; The post-operation temperature of the column box was 300° C., and backflushing was performed for 1.5 min.

8. The method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 7, characterized in that: The carrier gas of the Agilent 8890-7000D gas chromatograph coupled to a triple quadrupole mass spectrometer is helium, and the purity of the helium is ≥99.999%; The injection port temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer was 280° C. and the injection volume was 1 μL; The injection method is splitless injection; The electron bombardment source of the Agilent 8890-7000D gas chromatograph coupled to a triple quadrupole mass spectrometer is 70 eV; The ion source temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is 280°C; The transmission line temperature of the Agilent 8890-7000D gas chromatograph tandem triple quadrupole mass spectrometer is 280°C; The solvent delay of the Agilent 8890-7000D gas chromatograph coupled to a triple quadrupole mass spectrometer was 5 min.

9. The method for measuring the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 1, characterized in that: The extraction process uses a rapid solvent extractor, and the extraction solvent used by the rapid solvent extractor is methanol.

10. The method for determining the contents of o-phenylenediamine and 2-methylbenzimidazole according to claim 9, characterized in that: The temperature during the extraction is 75-100° C., the pressure is 1500 psi, the heating time is 5 min, the static time is 5 min, the flushing volume is 60%, the purge time is 100 seconds; and the number of cycles is 1.

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