A method for mass spectrometry analysis of aromatic isomers based on the electrochemical reactivity of thiamethoxam, its application and implementation device

Abstract

This invention discloses a mass spectrometry analysis method for aromatic isomers based on the electrochemical reactivity of thiazolium, as well as its application and implementation apparatus. The analytical method claimed in this invention includes: placing two or more aromatic isomers to be analyzed with thiazolium in a predetermined reaction system; applying a potential under conditions separate from the mass spectrometry ionization process to perform electrochemical derivatization; detecting the reaction by mass spectrometry; determining whether a thiazolium-derived product meeting a preset mass spectrometry criterion is formed based on the precursor ion information of the expected thiazolium-derived product and / or the characteristic fragment ion information of the thiazolium source; and determining the electrochemical reactivity of the analytical thiazolium based on this determination; when there are differences in the electrochemical reactivity of the analytical thiazolium among the aromatic isomers to be analyzed, using these differences to obtain structural analysis information to assist in distinguishing the aromatic isomers to be analyzed. This invention also claims protection for the application and implementation apparatus of this analytical method.

Description

Technical Field

[0001] This invention belongs to the field of analysis, specifically relating to a mass spectrometry analysis method for aromatic isomers based on the electrochemical analysis reactivity of thiamethoxam, and its application and implementation apparatus. Background Technology

[0002] Aromatic compounds are widely found in pharmaceuticals, metabolites, natural products, environmental pollutants, and various chemical and biological reaction systems. Due to differences in the way atoms are linked, substituted, or arranged in space, aromatic compounds contain a large number of isomers. These compounds have the same molecular formula and molecular mass, but their chemical structures and physicochemical properties may differ, thus requiring a high degree of structural differentiation in analytical identification.

[0003] Mass spectrometry, with its advantages of high sensitivity, fast analysis speed, and ability to obtain molecular mass and fragment ion information, has been widely used for the qualitative, quantitative, and structural analysis of small molecule compounds. For compounds with significant structural differences, information such as precursor ions, isotopic distribution, and tandem mass spectrometry fragments can be combined for identification. However, for some aromatic isomers, due to their identical molecular formula and molecular mass, and their similar or highly similar aromatic skeletons and functional groups, they may produce the same precursor ions and similar fragment ions under conventional mass spectrometry conditions. Therefore, relying solely on molecular mass and conventional tandem mass spectrometry information still limits the analytical dimensions available for distinguishing their structures.

[0004] To improve the analytical selectivity of isomers, existing techniques typically employ methods such as chromatographic separation, ion mobility separation, tandem mass spectrometry, and chemical derivatization to enhance structural identification information. Liquid chromatography (LC) can separate some isomers by utilizing the differences in interactions between different compounds and the stationary phase; however, the separation efficiency is usually affected by factors such as column type, mobile phase composition, and gradient conditions, often requiring targeted optimization for different target analytes. When dealing with a large number of candidate compounds or batches of samples, the long chromatographic separation time can also limit overall analytical efficiency. Chemical derivatization, on the other hand, can alter the ionization efficiency and mass spectrometric behavior of the target compound by introducing easily ionized groups, permanently charged groups, or structures with characteristic fragmentation behavior. However, traditional chemical derivatization usually relies on specific functional groups such as hydroxyl, amino, carboxyl, and carbonyl groups. When different isomers have the same or similar functional group compositions, the additional structural information obtained from conventional derivatization targeting the same functional group may still be insufficient to effectively reflect their molecular structural differences.

[0005] In order to overcome the shortcomings or defects of the existing technology, the applicant has developed a mass spectrometry analysis method for aromatic isomers, and hereby proposes this invention. Summary of the Invention

[0006] To address the challenge that some aromatic isomers with the same molecular formula and molecular weight produce the same or highly similar precursor ions in conventional mass spectrometry analysis and may exhibit similar fragmentation behavior, resulting in limited information available for structural differentiation, this invention provides a mass spectrometry analysis method for aromatic isomers based on the electrochemical analysis reactivity of thiaanthracite, along with its application and implementation apparatus.

[0007] This invention aims to utilize the structure-dependent reaction differences exhibited by different aromatic isomers under predetermined thiazoline electrochemical derivatization and mass spectrometry analysis conditions to transform molecular structural differences that are difficult to characterize by conventional molecular mass into analytical reactivity differences that can be detected by mass spectrometry. This provides an additional structural analysis dimension for aromatic isomers that is distinct from precursor ion mass and conventional fragment information.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution:

[0009] This invention provides a mass spectrometry method for analyzing aromatic isomers based on the electrochemical reactivity of thiazide. The method involves performing steps S1 to S3 on two or more aromatic isomers to be analyzed to determine the analytical thiazide electrochemical reactivity of each isomer. When there are differences in the analytical thiazide electrochemical reactivity among the aromatic isomers, structural analysis information is obtained using these differences to help distinguish the aromatic isomers.

[0010] Step S1: Add the aromatic isomer to be analyzed and thiaanthracite to the reaction system;

[0011] Step S2: Apply an electric potential to the reaction system to electrochemically oxidize thiaanthra to generate active species, and then cause the active species to undergo a derivatization reaction with the aromatic isomer to be analyzed to form thiaanthra derivatives.

[0012] Step S3: Mass spectrometry is performed on the reaction system obtained in step S2. Based on the precursor ion information of the expected thiathracene derivative and / or the characteristic fragment ion information of the thiathracene source, it is determined whether the aromatic isomer to be analyzed forms a thiathracene derivative that meets the preset mass spectrometry judgment criteria under the predetermined thiathracene electrochemical derivatization conditions. The analytical thiathracene electrochemical reactivity of the aromatic isomer to be analyzed is determined according to the judgment result.

[0013] The predetermined thiathracene electrochemical derivatization conditions described in this invention refer to pre-determined reaction conditions for obtaining repeatable and comparable analytical thiathracene electrochemical reactivity. These conditions may include one or more of the following: thiathracene dosage or concentration, electrolyte composition and concentration, reaction solvent, electrode materials and configuration, applied potential, reaction time, reaction volume, and reaction vessel. For the aromatic isomers to be compared, it is preferable to determine their analytical thiathracene electrochemical reactivity under the same key thiathracene electrochemical derivatization and mass spectrometry detection conditions.

[0014] The analytical thiazide electrochemical reactivity of this invention refers to the detectable reaction characteristics of an aromatic isomer of the analyte, under preset thiazide electrochemical derivatization and mass spectrometry detection conditions, to generate a thiazide derivative that yields a corresponding mass spectrometry detection signal. If, under specified conditions, the aromatic isomer of the analyte yields mass spectrometry evidence of a thiazide derivative that meets the preset mass spectrometry criteria, the analytical thiazide electrochemical reaction of the analyte is determined to be positive; if, under the same or corresponding conditions, no mass spectrometry evidence of a thiazide derivative that meets the aforementioned criteria is obtained, the analytical thiazide electrochemical reaction of the analyte is determined to be negative. This analytical thiazide electrochemical reactivity differs from the feasibility of a synthetic reaction evaluated by chemical synthesis yield and conversion efficiency at specific sites; its evaluation object is the thiazide derivative actually generated under specific analytical conditions and its mass spectrometry detection results.

[0015] In some embodiments, in addition to determining whether a thiaanthra derivative is formed that meets preset mass spectrometry criteria, the electrochemical reactivity of the analytical thiaanthra can be further characterized using one or more of the following: precursor ion response, characteristic fragment ion response, peak intensity, peak area, peak height, and normalized response of the thiaanthra derivative. The above information can be used as auxiliary analytical information, but is not required as a necessary condition for implementing the isomer-assisted differentiation method of the present invention.

[0016] In some embodiments, preliminary mass spectrometric evidence for candidate thiaanthracite derivatives can be obtained based on the matching of theoretical or expected precursor ions with measured precursor ions. Further, tandem mass spectrometry analysis can be performed on the candidate precursor ions, and the formation of thiaanthracite derivatives can be further confirmed based on characteristic fragment ions from the thiaanthracite source. In a preferred embodiment, the characteristic fragment ions from the thiaanthracite source include ions with a mass-to-charge ratio of approximately m / z 216. Various experimentally confirmed thiaanthracite derivatives can be observed with corresponding precursor ions and characteristic fragments of approximately m / z 216; this mass spectrometric evidence can be used to establish analytical thiaanthracite electrochemical reaction tags.

[0017] This invention does not require that all aromatic isomers with analytical thiazide electrochemical reactivity must obtain characteristic fragment ions of exactly the same strength; the precursor ions, characteristic fragments and derivative responses can be used alone or in combination to assist in characterizing the analytical thiazide electrochemical reactivity.

[0018] The differences in the electrochemical reactivity of the analytical thiazolium can be related to the molecular structure of the aromatic isomers and their local chemical environment, and may be influenced by one or more factors such as electronic properties, substitution environment, polarity, molecular size, spatial environment, and conformational accessibility. This invention utilizes the differences in analytical reactivity measurable under experimental conditions, rather than determining the specific contribution of the aforementioned factors or adhering to a particular reaction mechanism as a necessary condition for implementing this invention.

[0019] For aromatic isomers, although different isomers have the same molecular formula and molecular mass, their molecular structures and local chemical environments differ. Therefore, under predetermined thiaanthracite electrochemical derivatization conditions, they can exhibit different analytical thiaanthracite electrochemical reactivity. When at least one candidate isomer forms a thiaanthracite derivative that meets the preset mass spectrometry criteria, while at least another does not form a thiaanthracite derivative that meets the criteria, this difference in analytical reactivity can be directly used to provide auxiliary isomer differentiation information. In one embodiment, the aromatic isomers include aromatic positional isomers. For example, 1,2-dimethoxybenzene and 1,4-dimethoxybenzene, as well as catechol, resorcinol, and hydroquinone, can all be specific examples of the aromatic positional isomers.

[0020] Experimental evaluation of various structurally different aromatic isomers showed that different compounds exhibited different analytical thiazide electrochemical reactivity under uniform thiazide electrochemical derivatization conditions, indicating that this analytical reactivity is structure-dependent. Specific experimental results can be found in the corresponding examples.

[0021] To improve the repeatability of the electrochemical reactivity of the analytical thiazolium and the compatibility with subsequent mass spectrometry analysis, this invention further provides a preferred reaction system suitable for implementing the above method. In a preferred embodiment, a pair of paired graphite anodes and cathodes are used as working electrodes, and the graphite electrodes are inserted into a reaction solution containing the aromatic isomer to be analyzed and thiazolium for electrochemical reaction. Comparative experiments conducted by the applicant show that among various electrode materials tested, the target product response obtained by the graphite electrode is more regular and consistent; therefore, a graphite electrode is used in a preferred embodiment.

[0022] In a preferred embodiment, the reaction system comprises thiaanthracene, trifluoroacetic acid, and acetonitrile, wherein trifluoroacetic acid serves as the supporting electrolyte and / or acidic medium, and acetonitrile serves as the organic reaction solvent. The applicant's experimental results indicate that the acetonitrile system containing trifluoroacetic acid achieves a good balance in terms of thiaanthracene derivative response, mass spectrometry background, and overall performance among different substrates under the tested conditions. In a preferred embodiment, the reaction is carried out in a glass reaction vessel, more preferably a glass high-performance liquid chromatography (HPLC) sample vial; under the tested conditions, the glass reaction vessel yields a more regular and reproducible thiaanthracene derivative response.

[0023] The electrochemical derivatization process is separated from the subsequent mass spectrometry ionization process. After the electrochemical reaction is completed, analysis can be performed using methods such as direct microplate sampling mass spectrometry, flow injection mass spectrometry, electrospray mass spectrometry, liquid chromatography-mass spectrometry, or liquid chromatography-tandem mass spectrometry, depending on the analytical requirements. Among these, direct microplate sampling mass spectrometry can be used to rapidly obtain the reaction response of a large number of samples, while liquid chromatography-mass spectrometry or liquid chromatography-tandem mass spectrometry can be used for chromatographic separation and orthogonal confirmation of candidate thiaanthra derivatives.

[0024] In some embodiments, the aromatic isomers to be analyzed are compounds with the same molecular formula but different molecular structures, and the molecular structures contain at least one aromatic ring; each aromatic isomer to be analyzed is subjected to thiathracene electrochemical derivatization and mass spectrometry detection under the same or corresponding thiathracene concentration, electrolyte system, solvent system, electrode conditions, applied potential and reaction time conditions.

[0025] In some embodiments, the analytical thiathane electrochemical reactivity includes analytical thiathane electrochemical reaction positive and analytical thiathane electrochemical reaction negative; wherein, the analytical thiathane electrochemical reaction positive means that mass spectrometric evidence of thiathane derivatives meeting the preset mass spectrometry criteria is detected under the predetermined thiathane electrochemical derivatization conditions; the analytical thiathane electrochemical reaction negative means that no mass spectrometric evidence of thiathane derivatives meeting the preset mass spectrometry criteria is obtained under the same or corresponding predetermined thiathane electrochemical derivatization conditions.

[0026] In some embodiments, the thiaanthracite derivative includes an arylthiaanthracite derivative; the preset mass spectrometry determination criteria include at least one of the following (1) and (2):

[0027] (1) The measured precursor ions match the thiaanthra derivative precursor ions calculated or expected based on the aromatic isomers to be analyzed.

[0028] (2) Characteristic fragment ions from thiaethracene were detected after tandem mass spectrometry analysis of the precursor ions.

[0029] This invention further provides the application of the above-mentioned mass spectrometry analysis method for aromatic isomers in assisting in the differentiation of aromatic isomers. The aromatic isomers may include aromatic positional isomers and aromatic structural isomers with the same molecular formula but different aromatic ring substitution positions and / or functional group linkages. The following (a) to (h) are specific embodiments of this invention that have been experimentally verified, and do not constitute a limitation on the scope of aromatic isomers to which this invention applies:

[0030] (a) Vanillin and 2-hydroxy-5-methoxybenzaldehyde;

[0031] (b) 3-(4-hydroxyphenyl)propionic acid and 3-methoxyphenylacetic acid;

[0032] (c) 1,2-Dimethoxybenzene and 1,4-Dimethoxybenzene;

[0033] (d) Resorcinol, hydroquinone, and catechol;

[0034] (e) 3-hydroxyacetophenone and 4-hydroxyacetophenone;

[0035] (f) Methyl 2-hydroxybenzoate, methyl 3-hydroxybenzoate and methyl 4-hydroxybenzoate;

[0036] (g) 2,3-dihydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde and 3,5-dihydroxybenzaldehyde;

[0037] (h) Salicylic acid, 4-hydroxybenzoamide and 3-aminobenzoic acid.

[0038] This invention provides a high-throughput electrochemical reaction apparatus for implementing the aromatic isomer mass spectrometry analysis method described in any of the above claims. It includes a multi-channel DC voltage output unit, one or more reaction modules, multiple independent reaction containers, and replaceable electrode pairs corresponding to each reaction container. The electrode pairs are installed by an electrode fixing assembly to maintain the electrode spacing, insertion depth, and reaction liquid contact state in multiple reaction positions in a predetermined state.

[0039] In some embodiments, the reaction module is a printed circuit board reaction module, each printed circuit board reaction module is provided with multiple reaction positions, and each reaction position is respectively provided with a reaction container and an electrode group; the multi-channel DC voltage output unit includes multiple output channels that can independently set the applied voltage and reaction time, each output channel is electrically connected to at least one of the printed circuit board reaction modules, so that multiple samples to be analyzed can undergo parallel offline thiaanthra electrochemical derivatization reaction under the same or different predetermined electrochemical conditions.

[0040] In some embodiments, both the anode and cathode of the electrode assembly are graphite electrodes.

[0041] Beneficial effects:

[0042] This invention derivatizes the aromatic compound to be analyzed with thiaanthra under offline electrochemical conditions, and determines whether a product meeting the preset mass spectrometry criteria is formed based on the expected thiaanthra derivative precursor ions and / or characteristic fragment ions (including ion species and ion strength) of thiaanthra. This transforms molecular structural differences that are difficult to characterize with conventional mass spectrometry into analytical differences in the electrochemical reactivity of thiaanthra that can be detected by mass spectrometry. This difference can serve as an additional structural analysis dimension, distinguishing it from molecular mass, conventional precursor ions, and fragment ions, to help differentiate aromatic isomers with the same molecular formula and molecular mass, especially aromatic positional isomers, and provides new analytical basis for systems with limited information on conventional mass spectrometry structure identification. Attached Figure Description

[0043] Figure 1 This is a schematic diagram illustrating the principle and overall process of the mass spectrometry analysis method for aromatic isomers based on the electrochemical analysis reactivity of thiamethoxam according to the present invention.

[0044] Figure 2 , 3 The image shows the mass spectrometry results of the electrochemical derivatization of representative aromatic compounds to form thiaanthracite derivatives; among them, Figure 2 The electrochemical derivatization reaction and mass spectrometry detection results of thiaanthracite, a representative aromatic compound, are presented. Figure 3 The results are verified by liquid chromatography-tandem mass spectrometry for the corresponding thiaanthra derivatives.

[0045] Figure 4 , 5 The figure shows the screening results of the electrochemical derivatization reaction conditions for thiaanthra; among them, Figure 4 The results show the comparison of different electrode materials. Figure 5 The results show the comparison of different reaction vessels.

[0046] Figure 6 The figure shows the evaluation results of the electrochemical reactivity of various aromatic compounds under predetermined electrochemical derivatization and mass spectrometry detection conditions for analytical thiathracene. Among them, A is the repeated experimental response results of 138 aromatic compounds, B is the representative mass spectrometry results of positive and negative electrochemical reactions of analytical thiathracene, and C is the binary classification statistical results of the electrochemical reactivity of analytical thiathracene.

[0047] Figure 7 , 8 Figures 9 and 1 show the comparison and auxiliary differentiation results of the electrochemical reactivity of analytical thiazolium isomers of candidate aromatic isomers; among them, Figure 7 The results are shown in the DMS-MS target ion pair detection results for the corresponding thiaanthra derivatives. Figure 8The results are the DMS-MS primary mass spectrometry precursor ion detection results of the corresponding thiaanthra derivatives. Figure 9 The results are verified by liquid chromatography-tandem mass spectrometry for the corresponding thiaanthra derivatives.

[0048] Figure 10 , 11 This is a schematic diagram of a high-throughput electrochemical reaction apparatus for the batch implementation of the thiamethoxam electrochemical derivatization method of the present invention; wherein, Figure 10 This is a schematic diagram of the overall structure of the device. Figure 11 A schematic diagram of a single reaction site and electrode fixing method; Figure 10 , 11 In the middle section: 1 is a multi-channel voltage output unit, 2 is a voltage output interface, 3 is a connecting wire, 4 is a voltage input connector, 5 is an expansion port, 6 is a reaction container, 7 is a reaction support plate, 8 is an electrode plug-in end, 9 is a pluggable electrode fixing assembly, 10 is an electrode positioning hole, 11 is an electrode group, and 12 is a reaction solution. Detailed Implementation

[0049] The substantive content of the present invention is described in detail below with reference to specific embodiments. However, those skilled in the art should understand that the scope of protection of the present invention should not be limited to these specific embodiments. In the following embodiments, unless otherwise specified, the reagents and instruments used are all commercially available products in the art; the experimental methods and detection methods used are all conventional and well-known methods in the art, unless otherwise specified.

[0050] Unless otherwise specified, the following examples use thianthrene (TT) as the electrochemical derivatization reagent, acetonitrile as the reaction solvent, and trifluoroacetic acid (TFA) as the supporting electrolyte and / or acidic medium. All analytes, thianthrene, trifluoroacetic acid, and organic solvents used are commercially available analytical grade or chromatographic grade reagents.

[0051] After the electrochemical reaction is complete, the resulting reaction solution can be detected using direct microplate sampling mass spectrometry (DMS-MS) or liquid chromatography-mass spectrometry (LC-MS). Rapid mass spectrometry detection can be performed using a DMS-MS system with an open-port interface. The reacted sample is transferred to a microplate and sampled sequentially, using a 90% (v / v) acetonitrile aqueous solution as the transport fluid at a flow rate of approximately 550 μL / min. An LTQ XL mass spectrometer can be used in positive ion mode. Specific detection conditions include a spray voltage of approximately 5 kV, a capillary temperature of approximately 275 °C, a tube lens voltage of approximately 40 V, and a sheath gas pressure of approximately 55 arb. Depending on the detection objective, primary mass spectrometry, extracted ion current, selected reaction monitoring, and / or tandem mass spectrometry can be used to obtain the appropriate mass spectrometry information.

[0052] HPLC-MS validation can be performed using a Shimadzu LC-20A high-performance liquid chromatography system coupled with an LTQ XL mass spectrometer. The chromatographic column is an Ultimate AQ C18 column (2.1 mm × 150 mm, 3 μm), the column temperature is 40 ℃, mobile phase A is water containing 0.1% formic acid, mobile phase B is acetonitrile containing 0.1% formic acid, the flow rate is 0.3 mL / min, and the injection volume is 5 μL. For thiathracene derivatives that can produce stable characteristic fragments, selective reaction monitoring can be performed using target ion pairs with the corresponding thiathracene derivative precursor ion as the precursor ion and the characteristic fragment ion from thiathracene source at approximately m / z 216 as the product ion. The normalized collision energy during collision-induced dissociation can be set to approximately 45%. The above instrument model and parameters are one specific implementation method, and the present invention is not limited to the above-described mass spectrometry detection equipment and specific parameters.

[0053] Example 1: Electrochemical derivatization of representative aromatic compounds and mass spectrometric confirmation of thiaanthracite derivatives

[0054] This embodiment illustrates the formation of thiathracene derivatives from aromatic compounds via electrochemical derivatization, and establishes an analytical method for determining the electrochemical reactivity of thiathracene based on precursor ions of thiathracene derivatives and characteristic fragment ions from thiathracene sources.

[0055] 3-hydroxybenzyl alcohol (3-HBA), 2-naphthol (2-NP), aniline (ANI), and 1,2-dimethoxybenzene (1,2-DMB) were selected as representative aromatic compounds. Solutions of the above-mentioned compounds with a concentration of 20 μg / mL and solutions of thiaanthracite with a concentration of 200 μg / mL were prepared, both using acetonitrile containing 10 mM trifluoroacetic acid.

[0056] 500 μL of the analyte solution and 500 μL of thiamethoxam solution were mixed separately, resulting in a total reaction volume of 1.0 mL. The final concentration of the analyte was 10 μg / mL, and the final concentration of thiamethoxam was 100 μg / mL, with a mass concentration ratio of thiamethoxam to the analyte of 10:1. The reaction solution was added to a 2 mL glass high-performance liquid chromatography (HPLC) sample vial, and a pair of graphite electrodes were inserted. A 0 V control group and a 5 V electrochemical reaction group were set up. The 5 V group was subjected to a 5 V DC voltage for 10 min, while the 0 V group was the same as the control group except that no voltage was applied. After the reaction, the electrodes were removed, and the resulting reaction solution was analyzed under the mass spectrometry detection conditions described above. (Current patent) Figure 2 , 3 The corresponding implementation conditions adopted a 0 V and 5 V control and a 10 min reaction time, therefore this embodiment retains these specific experimental conditions.

[0057] Based on the expected quality of each compound after forming thiaanthra derivatives, the m / z values ​​of TT-3-HBA (339.1), TT-2-NP (359.1), TT-ANI (308.1), and TT-1,2-DMB (353.1) were monitored.

[0058] DMS-MS test results are as follows: Figure 2 As shown. Under 0 V control conditions, the target ions corresponding to the expected thiathracene derivatives did not form obvious and repetitive target responses; under 5 V electrochemical reaction conditions, 3-HBA, 2-NP, ANI, and 1,2-DMB all obtained obvious target ion responses for their respective thiathracene derivatives. The corresponding ions with m / z of approximately 339.1, 359.1, 308.1, and 353.1 were detected in DMS-MS primary mass spectrometry, consistent with the expected thiathracene derivatives of TT-3-HBA, TT-2-NP, TT-ANI, and TT-1,2-DMB.

[0059] To further confirm the target ions, the samples obtained from the 5 V reaction were analyzed by liquid chromatography-tandem mass spectrometry, and the target ion pairs were monitored at m / z 339→216 for TT-3-HBA, m / z 359→216 for TT-2-NP, m / z 308→216 for TT-ANI, and m / z 353→216 for TT-1,2-DMB.

[0060] The results of the liquid chromatography-tandem mass spectrometry validation are as follows: Figure 3As shown, all four thiathracene derivatives exhibited a clear chromatographic response from the corresponding precursor ion to the product ion at approximately m / z 216. Furthermore, tandem mass spectrometry analysis of the corresponding precursor ions revealed characteristic fragment ions of thiathracene origin at approximately m / z 216. These results further support the view that the detected target precursor ions originate from the corresponding thiathracene-containing derivatives.

[0061] Based on the above experimental results, in a preferred determination method, when both a precursor ion matching the expected thiaanthracite derivative and a thiaanthracite-derived characteristic fragment ion generated by tandem mass spectrometry analysis of the precursor ion are simultaneously obtained, the corresponding aromatic compound to be analyzed is considered to have formed a thiaanthracite derivative that meets the preset mass spectrometry determination criteria, and is determined to be a positive electrochemical reaction of analytical thiaanthracite. Preferably, the ion with m / z approximately 216 is used in conjunction with the corresponding thiaanthracite derivative precursor ion and its tandem mass spectrometry relationship, rather than using the m / z approximately 216 ion appearing alone in the reaction system as the sole criterion for the formation of the thiaanthracite derivative.

[0062] Under the conditions used in this embodiment, 3-HBA, 2-NP, ANI, and 1,2-DMB all yielded evidence of precursor ions of the corresponding thiathracene derivatives and characteristic fragment ions of thiathracene origin, and were therefore all determined to be positive for analytical thiathracene electrochemical reactions. These results demonstrate that by performing thiathracene electrochemical derivatization under specified conditions and detecting mass spectrometric evidence of the corresponding thiathracene derivatives, the analytical thiathracene electrochemical reactivity of aromatic compounds can be obtained, providing a basis for subsequent comparison of reactivity differences among candidate aromatic isomers.

[0063] Example 2: Screening of electrode materials and reaction vessels in the electrochemical reactivity test of thiaanthracite

[0064] This embodiment is used to compare the effects of different electrode materials and reaction vessels on the electrochemical derivatization results of thiaanthracite and to determine the preferred reaction unit for subsequent analytical comparison of the electrochemical reactivity of thiaanthracite.

[0065] Using 3-HBA, 2-NP, ANI, and 1,2-DMB from Example 1 as representative aromatic compounds, electrochemical derivatization experiments of thiaanthracite were conducted using iron, copper, gold-plated, platinum, and graphite electrodes, respectively. Except for the electrode materials investigated, the analyte, TT, TFA, reaction solvent, reaction volume, applied potential, reaction time, and subsequent mass spectrometry detection conditions remained consistent for each group. After the reaction, analysis was performed under the aforementioned mass spectrometry detection conditions, and the m / z values ​​were monitored for TT-3-HBA (339.1), TT-2-NP (359.1), TT-ANI (308.1), and TT-1,2-DMB (353.1).

[0066] The results are as follows Figure 4As shown, the responses of the target thiaanthra derivatives obtained under different electrode material conditions differ. The responses of some target ions are weaker or more volatile under iron and copper electrode conditions; the responses of gold-plated and platinum electrodes show some compound dependence; in contrast, the graphite electrode obtained more regular and consistent reproducible target responses for all four representative aromatic compounds. Therefore, considering the regularity and repeatability of the responses of different analytes, the graphite electrode was selected as a preferred electrode material for subsequent analytical evaluation of the electrochemical reactivity of thiaanthra. This result is consistent with the experimental result that the graphite electrode obtained the most regular and consistent peak shape.

[0067] Further comparisons were made regarding the reaction vessel types. Two mL glass high-performance liquid chromatography (HPLC) vials, 96-well plate wells, and microcentrifuge tubes were used as reaction vessels, with 3-HBA, 2-NP, ANI, and 1,2-DMB as representative analytes. Except for the reaction vessel, the concentrations of the analytes, TT concentrations, TFA concentrations, solvent systems, electrode materials, applied potentials, reaction times, and mass spectrometry detection conditions remained consistent across groups. After the reaction, the target ions of the four corresponding thiathracene derivatives were detected. The results are as follows: Figure 5 As shown, when using 2 mL glass high-performance liquid chromatography (HPLC) vials, TT-3-HBA, TT-2-NP, TT-ANI, and TT-1,2-DMB all obtained relatively regular and consistent repeatable target responses. However, when using 96-well plates or microcentrifuge tubes, the response fluctuations of some analytes increased, or the regularity of the repeatable peaks decreased. Therefore, under the conditions tested in this embodiment, 2 mL glass HPLC vials were selected as the preferred reaction vessel for subsequent electrochemical derivatization of thiaanthracite.

[0068] Based on the above results, subsequent embodiments preferably use a pair of graphite electrodes and a 2 mL glass high-performance liquid chromatography sample vial as the thiaanthra electrochemical reaction unit. For candidate aromatic isomers requiring direct comparison of analytical thiaanthra electrochemical reactivity, all candidate compounds are reacted using electrodes of the same materials and configuration, reaction vessels of the same specifications, and under the same key thiaanthra electrochemical derivatization conditions to improve the comparability of analytical thiaanthra electrochemical reactivity results obtained from different candidate compounds.

[0069] Example 3: Evaluation of the electrochemical reactivity of various aromatic compounds in analytical thiaanthracite

[0070] This embodiment is used to evaluate the analytical electrochemical reactivity of aromatic compounds with different structures under unified thiathracene electrochemical derivatization and mass spectrometry analysis conditions.

[0071] 138 aromatic compounds with different aromatic skeletons, functional group compositions, and substitution modes were selected for experiments. 500 μL of the analyte solution (2 μg / mL) and 500 μL of thiaanthra solution (20 μg / mL) were mixed to obtain a total reaction volume of 1.0 mL, with the analyte concentration at 1 μg / mL and the thiaanthra concentration at 10 μg / mL. Both the analyte and thiaanthra were prepared using acetonitrile solution containing 10 mM trifluoroacetic acid. The reaction solution was placed in a 2 mL glass high-performance liquid chromatography (HPLC) vial, and a pair of graphite electrodes were used to react at 5 V DC for 5 min. Each compound was tested three times independently, and the results were analyzed using DMS-MS with data-dependent acquisition after the reaction.

[0072] For each analyte, the expected precursor ion of the corresponding thiaanthracite derivative is calculated based on its molecular structure. In this example, the calculation is performed with the aromatic hydrogen replaced by the thiaanthracite source group, resulting in an increase of 214.9989 Da relative to the original compound. During mass spectrometry matching, the allowable mass deviation for the candidate thiaanthracite derivative precursor ion is ±0.60 Da, and the allowable mass deviation for the characteristic fragment ion of thiaanthracite source at m / z approximately 216 is ±0.40 Da. In a single independent experiment, if a precursor ion matching the expected thiaanthracite derivative is obtained simultaneously, and a characteristic fragment ion of thiaanthracite source at m / z approximately 216 is obtained from the corresponding precursor ion, the experiment is considered to have obtained complete mass spectrometric evidence for the thiaanthracite derivative; if only precursor ion or partial fragment evidence is obtained, the requirement for complete mass spectrometric evidence is not met.

[0073] Based on the results of three independent experiments, the binary analytical thiathane electrochemical reactivity of 138 aromatic compounds was determined. Under the preset criteria used in this embodiment, compounds that yielded stable and reproducible evidence of the expected thiathane derivative precursor ions and corresponding thiathane-derived fragment ions in all three independent experiments were determined to have a positive analytical thiathane electrochemical reaction; compounds that did not meet the above positive criteria were determined to have a negative analytical thiathane electrochemical reaction.

[0074] Experimental results are as follows Figure 6 As shown: A shows the response results of 138 aromatic compounds in three independent experiments of thiaanthra derivatives; B shows the representative mass spectrometry results of positive and negative compounds in the analytical thiaanthra electrochemical reaction; C shows the final binary classification statistical results.

[0075] Of the 138 aromatic compounds tested, 39 compounds obtained stable and reproducible evidence of the expected thiathracene derivative precursor ions and thiathracene-derived fragment ions, and were judged as positive for analytical thiathracene electrochemical reactions, accounting for 28.3%; the remaining 99 compounds did not meet the above positive criteria and were judged as negative for analytical thiathracene electrochemical reactions, accounting for 71.7%.

[0076] like Figure 6 As shown in Figure B, the representative compound with a positive electrochemical reaction of analytical thiathracene was able to simultaneously obtain a precursor ion that matched the expected thiathracene derivative and a thiathracene-derived fragment ion with a m / z of approximately 216 generated from the corresponding precursor ion; the representative compound with a negative electrochemical reaction of analytical thiathracene, however, did not obtain complete product evidence that simultaneously met the above-mentioned preset mass spectrometry criteria.

[0077] The above results indicate that aromatic compounds with different structures can exhibit different analytical thiazide electrochemical reactivity under the same thiazide electrochemical derivatization and mass spectrometry analysis conditions, suggesting that this reactivity is structure-dependent. This provides an experimental basis for further utilizing the reactivity differences between candidate aromatic isomers to obtain auxiliary structural analysis information.

[0078] It should be noted that the negative analytical thiathracene electrochemical reaction in this embodiment means that the corresponding compound did not obtain thiathracene derivative mass spectrometry evidence that met the positive determination requirements under the above-mentioned reaction conditions and mass spectrometry determination criteria. It does not mean that the corresponding compound absolutely cannot undergo thiathracene-related chemical reactions under other reaction conditions.

[0079] In one optional implementation, a predictive model can be established using the experimental analytical thiazide electrochemical reactivity results of the known structural aromatic compounds obtained in Example 3 to assist in screening candidate aromatic isomer combinations that may have different analytical thiazide electrochemical reactivity. Specifically, molecular descriptors and / or molecular structural fingerprints are calculated based on the molecular structures of each known structural aromatic compound, and the experimentally obtained analytical thiazide electrochemical reactivity binary labels are used as supervised learning labels to train a classification model. The classification model can employ random forest, logistic regression, support vector machine, or other models capable of classification or probability prediction based on molecular structure information. In one specific implementation, the experimental results of the 138 aromatic compounds described in Example 3 are used as model data, with 39 analytical thiazide electrochemical reaction positive compounds serving as model positive samples and 99 analytical thiazide electrochemical reaction negative compounds serving as model negative samples.

[0080] RDKit molecular descriptors were calculated based on the standardized molecular structures of each compound. After preprocessing for missing values, low-variance features, and highly correlated features, a random forest classification model was used for training. In one specific model, the random forest consisted of 600 decision trees, and 130 preprocessed input features were used for the final model training. Hierarchical 5-fold cross-validation was used to evaluate the model performance, and the final prediction model was retrained on all training samples. The established random forest model can probabilistically distinguish between positive and negative samples in the electrochemical reaction of analytical thiathracene based on molecular structure information, with an out-of-fold prediction ROC-AUC of approximately 0.88. The trained model outputs the predicted probability of forming thiathracene derivatives that meet preset mass spectrometry criteria under the corresponding electrochemical derivatization and mass spectrometry analysis conditions based on the molecular structure of the aromatic compound to be predicted.

[0081] For two or more aromatic isomers with known candidate structures, their predicted probabilities can be obtained separately. Candidate combinations whose predicted results indicate potential differences in analytical thiathracene electrochemical reactivity are prioritized for actual thiathracene electrochemical derivatization and mass spectrometry verification. The prediction model is used for pre-screening of candidate compounds and candidate isomer combinations, and is not directly used to determine isomer identity; the actual analytical thiathracene electrochemical reactivity of each candidate compound is still based on the results of thiathracene electrochemical derivatization and mass spectrometry experiments.

[0082] Example 4: Aromatic isomer differentiation based on differences in the electrochemical reactivity of analytical thiazolium

[0083] This embodiment illustrates that candidate aromatic isomers with the same molecular formula and molecular weight can exhibit different analytical thiathane electrochemical reactivity under the same thiathane electrochemical derivatization conditions, and this difference can be used to obtain auxiliary structural analysis information.

[0084] The following eight candidate aromatic isomers were selected for verification: vanillin (VAN) and 2-hydroxy-5-methoxybenzaldehyde (2H5OMe-Bzald); 3-(4-hydroxyphenyl)propionic acid (4-HPPA) and 3-methoxyphenylacetic acid (3-HPPA). acid, 3-MPAA; 1,2-dimethoxybenzene (1,2-DMB) and 1,4-dimethoxybenzene (1,4-DMB); resorcinol (RES), hydroquinone (HQ) and catechol (CAT); 3-hydroxyacetophenone (3-HAP) and 4-hydroxyacetophenone (4-HAP); methyl 2-hydroxybenzoate (Me2HB), methyl 3-hydroxybenzoate (Me3HB) and methyl 4-hydroxybenzoate (Me3HB) 4-hydroxybenzoate (Me4HB); 2,3-dihydroxybenzaldehyde (2,3-DHBAld), 2,4-dihydroxybenzaldehyde (2,4-DHBAld), 3,4-dihydroxybenzaldehyde (3,4-DHBAld), and 3,5-dihydroxybenzaldehyde (3,5-DHBAld); salicylamide (SalAm), 4-hydroxybenzamide (4-HBAm), and 3-aminobenzoic acid (3-ABA). The compounds in each of the above candidate groups have the same molecular formula and molecular weight, but differ in their substitution positions and / or functional group linkages.

[0085] Each candidate compound was subjected to thiaanthra electrochemical derivatization under the conditions described in Example 3, using a pair of graphite electrodes, a 2 mL glass high-performance liquid chromatography (HPLC) vial, and an acetonitrile reaction system containing trifluoroacetic acid. The mass concentration ratio of thiaanthra to the analyte was approximately 10:1, and the reaction was carried out at 5 V DC for 5 min. After the reaction, the target ion pairs and primary mass spectrometry information were obtained by DMS-MS, and the corresponding thiaanthra derivatives were further verified by liquid chromatography-tandem mass spectrometry.

[0086] Since the same group of candidate isomers has the same theoretical mass of thiane derivatives, this embodiment does not distinguish isomers based on the mass-to-charge ratio of the theoretical thiane derivatives themselves, but compares whether each candidate compound actually forms a thiane derivative that meets the preset mass spectrometry criteria under the same reaction conditions.

[0087] Among them, VAN and 2H5OMe-Bzald were used to monitor the expected thiaanthracite derivative precursor ion at approximately 367.0 m / z and the target ion pair at 367.0→216.0 m / z; 4-HPPA and 3-MPAA were used to monitor m / z at approximately 381.1 m / z and 381.1→216.0 m / z; 1,2-DMB and 1,4-DMB were used to monitor m / z at approximately 353.1 m / z and 353.1→216.0 m / z; RES, HQ, and CAT were used to monitor m / z at approximately 325.0 m / z and 325.0→216.0 m / z; 3-HAP and 4 -HAP monitoring m / z approximately 351.1 and 351.1→216.0; Me2HB, Me3HB and Me4HB monitoring m / z approximately 367.0 and 367.0→216.0; 2,3-DHBAld, 2,4-DHBAld, 3,4-DHBAld and 3,5-DHBAld monitoring m / z approximately 353.0 and 353.0→216.0; SalAm, 4-HBAm and 3-ABA monitoring m / z approximately 352.0 and 352.0→216.0.

[0088] DMS-MS target ion pair detection results are as follows Figure 7 As shown, the precursor ion detection results of DMS-MS primary mass spectrometry are as follows: Figure 8 As shown, different candidate isomers exhibited different formation states of thiaanthracite derivatives under the same reaction conditions. Further verification was performed using liquid chromatography-tandem mass spectrometry, with the corresponding thiaanthracite derivative precursor ions as precursor ions and the characteristic fragment ions of thiaanthracite source at m / z approximately 216 as product ions. The results are shown in the figure. Figure 9 As shown.

[0089] According to the preset mass spectrometry criteria described in Example 1, under the conditions adopted in this example, VAN showed a positive analytical thiazoline electrochemical reaction and a negative 2H5OMe-Bzald; 4-HPPA was positive and 3-MPAA was negative; 1,2-DMB was positive and 1,4-DMB was negative; RES was positive and HQ and CAT were negative; 3-HAP and 4-HAP were both positive; Me2HB was negative and Me3HB and Me4HB were positive; 2,3-DHBAld and 3,4-DHBAld were negative, and 2,4-DHBAld and 3,5-DHBAld were positive; SalAm was negative and 4-HBAm and 3-ABA were positive. Among them, analytical thiathracene electrochemical reaction positive compounds such as VAN, 4-HPPA, 1,2-DMB and RES all obtained precursor ions that matched the expected thiathracene derivatives, and obtained evidence of thiathracene-derived fragment ions with m / z of approximately 216 generated by the corresponding precursor ions; their corresponding isomers did not obtain evidence of thiathracene derivatives that met the preset mass spectrometry determination criteria under the same conditions.

[0090] Taking 1,2-DMB and 1,4-DMB as examples, both have the same molecular formula and molecular weight, and their corresponding theoretical thiathracene derivatives are both located at approximately m / z 353.1. The two cannot be distinguished solely based on the mass of the original compound or the theoretical thiathracene derivative. Under the same electrochemical derivatization conditions for thiathracene, 1,2-DMB can detect the corresponding thiathracene derivative precursor ion at approximately m / z 353.1 and obtains a target ion pair response from 353.1 to 216.0; while 1,4-DMB does not obtain evidence of the corresponding thiathracene derivative that meets the preset mass spectrometry criteria. Therefore, the difference in the analytical electrochemical reactivity of the two thiathracenes can be used to obtain auxiliary distinguishing information.

[0091] Similarly, among the three dihydroxybenzene positional isomers RES, HQ, and CAT, RES shows a positive electrochemical reaction for analytical thiazolium, while HQ and CAT show negative reactions. Therefore, this difference in reactivity can be used to help distinguish RES from HQ and CAT. However, since HQ and CAT are both negative under the above binary determination, the electrochemical reactivity of analytical thiazolium alone cannot further distinguish HQ and CAT.

[0092] This embodiment also demonstrates that both 3-HAP and 4-HAP exhibit positive analytical thiazide electrochemical reactivity under specified conditions; therefore, the two cannot be distinguished solely based on the binary reactivity index of positive / negative. This invention does not require all aromatic isomers to exhibit different analytical thiazide electrochemical reactivity, but rather utilizes the actual differences in analytical thiazide electrochemical reactivity among candidate aromatic isomers as additional structural analysis information.

[0093] The above results indicate that although aromatic isomers have the same molecular formula and molecular weight, their structural differences can be transformed into different thiathracene derivative formation states under specified thiathracene electrochemical derivatization conditions. When candidate aromatic isomers have different analytical thiathracene electrochemical reactivity, this difference can be used to narrow down the candidate structural range or to help distinguish the corresponding aromatic isomers.

[0094] Example 5: High-throughput implementation of the thiamethoxam electrochemical analysis method of the present invention

[0095] This embodiment illustrates that the aromatic isomer mass spectrometry analysis method based on the electrochemical analysis reactivity of thiathracene described in this invention can be implemented in batches using a multi-site electrochemical reaction device to improve the offline thiathracene electrochemical derivatization efficiency of multiple analyte compounds or multiple groups of candidate aromatic isomers.

[0096] The high-throughput electrochemical reaction device used in this embodiment is as follows: Figure 10 and Figure 11 As shown, the device includes a multi-channel voltage output unit 1, one or more reaction support plates 7, multiple reaction containers 6, and electrode groups 11 corresponding to each reaction container 6. The multi-channel voltage output unit 1 has multiple voltage output interfaces 2, each of which is electrically connected to a voltage input connector 4 on the corresponding reaction support plate 7 via connecting wires 3, for providing DC voltage to the corresponding reaction module. In one specific embodiment, the multi-channel voltage output unit 1 has four independently controllable DC voltage output channels, each of which can be set with an applied voltage and reaction time. The device uses four reaction support plates 7, each with 10 reaction positions, thus forming 40 electrochemical reaction positions capable of accommodating independent reaction samples. The reaction support plates 7 can be printed circuit boards, with conductive lines for connecting different reaction positions, voltage input connectors 4, and expansion ports 5; the expansion ports 5 can be used to connect other compatible reaction modules to expand the reaction positions according to the number of samples.

[0097] like Figure 11 As shown, each reaction position corresponds to a reaction vessel 6, and is equipped with an electrode insertion terminal 8, a pluggable electrode fixing assembly 9, an electrode positioning hole 10, and an electrode assembly 11. The reaction vessel 6 is used to contain a reaction solution 12 composed of the compound to be analyzed, TT, TFA, and a reaction solvent. The electrode assembly 11 includes paired anodes and cathodes, preferably using the graphite electrodes screened in Example 2. The electrode assembly 11 is installed via the pluggable electrode fixing assembly 9, and the installation position is defined by the electrode positioning hole 10, so that the spacing, insertion direction, insertion depth, and contact state with the reaction solution of the electrodes in different reaction positions are maintained in a predetermined state. The reaction vessel 6 is preferably a 2 mL glass high-performance liquid chromatography sample vial.

[0098] In implementing the method of this invention, multiple aromatic compounds or candidate aromatic isomers to be analyzed are added to different reaction vessels 6, and a predetermined TT electrochemical reaction system is added to each. For candidate isomers for which direct comparison of analytical TT electrochemical reactivity is required, different compounds in the same candidate group are subjected to the same TT concentration, TFA concentration, solvent system, reaction volume, electrode material, applied potential, and reaction time. After installing the electrode assembly 11, a predetermined DC voltage is applied to the corresponding reaction support plate 7 through the multi-channel voltage output unit 1, so that the samples in multiple independent reaction vessels can be simultaneously subjected to offline TT electrochemical derivatization. In one specific embodiment, the acetonitrile reaction system containing TFA described in Examples 3 and 4, the TT to analyte mass concentration ratio of approximately 10:1, and a 5 V DC voltage can be used for the reaction. Different voltage output channels can be set with the same reaction conditions for simultaneous processing of multiple samples, or different electrochemical conditions can be set for comparison of reaction conditions.

[0099] After the predetermined reaction time is reached, the voltage output is stopped and electrode assembly 11 is removed. The resulting reaction solution can be transferred to a microplate and analyzed by DMS-MS according to the aforementioned general mass spectrometry detection conditions. For thiaanthra derivatives requiring further confirmation, liquid chromatography-mass spectrometry or liquid chromatography-tandem mass spectrometry can be used for detection. For each compound to be analyzed, according to the determination method described in Example 1, it is determined whether it forms a thiaanthra derivative that meets the preset mass spectrometry determination criteria based on the corresponding expected thiaanthra derivative precursor ions and thiaanthra source characteristic fragment ions, and its analytical thiaanthra electrochemical reactivity is determined accordingly.

[0100] For example, 1,2-DMB and 1,4-DMB from Example 4 can be placed at different reaction sites and simultaneously electrochemically derivatized under the same conditions of TT concentration, TFA concentration, acetonitrile system, graphite electrode, applied potential, and reaction time. After the reaction, the m / z of the corresponding expected thiaanthra derivatives of both can be detected as approximately 353.1 for the precursor ion and 353.1→216.0 for the target ion pair. The results are processed according to the determination method described in Example 4. When 1,2-DMB obtains evidence of thiaanthra derivatives that meet the preset mass spectrometry determination criteria, while 1,4-DMB does not obtain corresponding evidence under the same conditions, the difference in the electrochemical reactivity of the two analytical thiaanthra compounds can be used to obtain auxiliary structural analysis information.

[0101] Similarly, multiple groups of candidate aromatic isomers can be simultaneously placed at different reaction sites to complete the electrochemical derivatization of thiaanthracite in the same batch, and the analytical thiaanthracite electrochemical reactivity of each candidate compound can be obtained in batches by combining subsequent rapid mass spectrometry detection.

[0102] The above results show that Figure 10 , 11The multi-channel electrochemical reaction apparatus shown can be used as a batch implementation of the method of the present invention to improve the processing efficiency of thiaanthra electrochemical derivatization and subsequent mass spectrometry evaluation of multiple aromatic compounds or multiple groups of candidate aromatic isomers. This high-throughput device is not a necessary condition for implementing the core analytical method of the present invention. The present invention can also be implemented using other single-sample or multi-sample reaction apparatuses capable of performing offline thiaanthra electrochemical derivatization under predetermined conditions.

[0103] The purpose of the above embodiments is to specifically illustrate the substantive content of the present invention, but those skilled in the art should know that the scope of protection of the present invention should not be limited to the specific embodiments.

Claims

1. A method of mass spectrometric analysis of aromatic isomers based on thianthrene electrochemical analytical reactivity, characterized by: The two or more than two to-be-analyzed aromatic isomers are subjected to the following steps S1 to S3 to determine the analytical thianthrene electrochemical reactivity of each to-be-analyzed aromatic isomer; when there is a difference in the analytical thianthrene electrochemical reactivity between the to-be-analyzed aromatic isomers, the difference is used to obtain structural analysis information for assisting in distinguishing the to-be-analyzed aromatic isomers: Step S1, adding the to-be-analyzed aromatic isomer and thianthrene into a reaction system; Step S2, applying a potential to the reaction system to make the thianthrene electrochemically oxidized to generate an active species, and make the active species and the to-be-analyzed aromatic isomer undergo a derivatization reaction to form a thianthrene derivative product; Step S3, detecting the reaction system obtained in step S2 by mass spectrometry, judging whether the to-be-analyzed aromatic isomer forms a thianthrene derivative product meeting a preset mass spectrometry judgment standard under a predetermined thianthrene electrochemical derivatization condition based on precursor ion information and / or thianthrene-derived characteristic fragment ion information of the expected thianthrene derivative product, and determining the analytical thianthrene electrochemical reactivity of the to-be-analyzed aromatic isomer according to the judgment result.

2. The method of aromatic isomer mass spectral analysis of claim 1, wherein, The to-be-analyzed aromatic isomer is a compound having the same molecular formula but different molecular structures, and containing at least one aromatic ring in the molecular structure.

3. The method of aromatic isomer mass spectral analysis of claim 1, wherein, The analytical thianthrene electrochemical reactivity includes analytical thianthrene electrochemical reaction positive and analytical thianthrene electrochemical reaction negative; wherein the analytical thianthrene electrochemical reaction positive refers to detecting mass spectrometry evidence of a thianthrene derivative product meeting a preset mass spectrometry judgment standard under a predetermined thianthrene electrochemical derivatization condition; and the analytical thianthrene electrochemical reaction negative refers to not obtaining mass spectrometry evidence of a thianthrene derivative product meeting the preset mass spectrometry judgment standard under the predetermined thianthrene electrochemical derivatization condition.

4. The method of aromatic isomer mass spectral analysis of claim 1, wherein, The thianthrene derivative product includes an arylthianthrenium derivative product.

5. The method of mass spectrometric analysis of aromatic isomers according to any one of claims 1 to 4, characterized in that, The thianthrene electrochemical derivatization is performed by using mutually paired graphite anodes and graphite cathodes which are inserted into the reaction system.

6. The method of aromatic isomer mass spectral analysis according to any one of claims 1 to 4, wherein The reaction system includes thianthrene, trifluoroacetic acid and acetonitrile; the thianthrene electrochemical derivatization is performed offline in a glass reaction vessel under conditions separated from the ionization process of mass spectrometry; and after the reaction is completed, one or more of direct microwell plate sampling mass spectrometry, flow injection mass spectrometry, electrospray mass spectrometry, liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry is used to detect the mass spectrometry of the obtained reaction solution.

7. Application of the aromatic isomer mass spectrometry analysis method of any one of claims 1 to 6 in assisting in distinguishing aromatic isomers; the aromatic isomers are aromatic structural isomers having the same molecular formula and containing at least one aromatic ring, but different aromatic ring substitution positions and / or functional group connection modes.

8. A high-throughput electrochemical reaction device for performing the method of mass spectrometric analysis of aromatic isomers according to any one of claims 1 to 6, characterized in that, The multi-channel direct current voltage output unit, one or more reaction modules, a plurality of mutually independent reaction vessels and a replaceable electrode pair corresponding to each reaction vessel are included; the electrode pair is installed by an electrode fixing assembly to keep the electrode spacing, insertion depth and reaction liquid contact state in the plurality of reaction positions in a predetermined state.

9. The high flux electrochemical reaction device of claim 8, wherein, The reaction module is a printed circuit board reaction module, each printed circuit board reaction module is provided with a plurality of reaction positions, each reaction position is respectively provided with a reaction container and an electrode group; the multi-channel direct current voltage output unit includes a plurality of output channels capable of independently setting an applied voltage and a reaction time, each output channel is electrically connected with at least one printed circuit board reaction module, so that a plurality of samples to be analyzed can perform parallel offline thianthrene electrochemical derivatization reactions under the same or different predetermined electrochemical conditions.

10. The high flux electrochemical reaction device of claim 8 or 9, wherein, The anode and the cathode of the electrode group are both graphite electrodes.

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