A method for non-targeted identification of perfluorinated compounds in plastic consumer goods

Abstract

This application belongs to the field of material analysis and identification technology, and provides a non-targeted identification method for perfluorinated compounds in plastic consumer products. The method includes pretreatment of plastic consumer product samples to obtain a test solution, analysis of the test solution using liquid chromatography-tandem mass spectrometry (LC-MS / MS), and execution of a collaborative acquisition strategy including iterative data-dependent acquisition mode, full-scan acquisition mode, and target data-dependent acquisition mode to obtain mass spectrometry data. Based on the mass spectrometry data, material identification is performed to obtain the perfluorinated compound identification result. The proposed scheme integrates the advantages of multiple mass spectrometry acquisition modes, can accommodate the identification needs of perfluorinated compounds with different abundances, improves the ability to detect suspicious signals, enables the identification of emerging perfluorinated compounds in complex matrix backgrounds, and reduces the risk of missed detection in conventional screening methods, thereby providing technical support for the safety evaluation of plastic consumer products.

Description

Technical Field

[0001] This application belongs to the field of material analysis and identification technology, specifically relating to a non-targeted identification method for perfluorinated compounds in plastic consumer products. Background Technology

[0002] Perfluorinated compounds (PFAS), also known as perfluorinated and polyfluoroalkyl substances, are a class of synthetic organic chemicals containing a perfluorinated methyl or methylene group. With their high stability and surface activity, they have excellent performance in applications such as adhesion, waterproofing, and high temperature resistance, and are widely used in the manufacture of consumer products such as non-stick coatings and waterproof fabrics.

[0003] Existing research indicates that perfluorinated compounds (PFCs) are persistent, bioaccumulative, and potentially toxic, posing a threat to the environment and human health. Traditional PFCs such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) have been banned and are subject to strict regulation under standards. Currently, industry is shifting towards using emerging PFCs as alternatives, but most of these emerging PFCs are not yet included in regulatory testing scopes. Because these emerging PFCs have structures similar to traditional PFCs, there is evidence that they also possess significant persistence, bioaccumulation, and potential toxicity; therefore, the potential environmental and health risks of emerging PFCs also require close attention.

[0004] Currently, many products, such as plastic products, contain a large number of plasticizers, antioxidants, light stabilizers and other chemicals to improve their performance. The variety of additives and the wide range of concentrations create extremely high chemical background noise. Even after pretreatment and enrichment, complex background irrelevant ions may still mask trace amounts of added perfluorinated compounds during chromatographic separation and mass spectrometry detection. Therefore, conventional screening methods are prone to false negatives and cannot achieve an effective non-targeted identification method for perfluorinated compounds in plastic consumer products. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this application proposes a non-targeted identification method for perfluorinated compounds in plastic consumer products, the method comprising:

[0006] The plastic consumer product sample was pretreated to obtain the test solution; The test solution was analyzed by liquid chromatography-tandem mass spectrometry, and a collaborative acquisition strategy including iterative data-dependent acquisition mode, full scan acquisition mode and target data-dependent acquisition mode was executed to obtain mass spectrometry data; Based on the mass spectrometry data, substance identification was performed to obtain the identification results of perfluorinated compounds.

[0007] Specifically, the pretreatment of the plastic consumer product sample to obtain the test solution includes: The plastic consumer product sample was cut into several block-shaped samples of the same specification; The block sample was subjected to ultrasonic-assisted extraction with a solvent to obtain an extract. The extract was subjected to nitrogen blowing concentration, volume adjustment and membrane filtration in sequence to obtain the test solution.

[0008] Preferably, the collaborative acquisition strategy includes: First, the iterative data-dependent acquisition mode is performed multiple times on the test liquid; The full scan acquisition mode was then performed once on the test liquid; Finally, a pre-identified ion list is generated based on the identification results of the data acquired in the full-scan acquisition mode. After removing duplicate ions in the pre-identified ion list that have already obtained secondary mass spectrometry data through the iterative data-dependent acquisition mode, the target data-dependent acquisition mode is applied to the test solution.

[0009] Specifically, the iterative data-dependent acquisition mode is used to acquire secondary mass spectrometry data of high-abundance ions in the plastic consumer product sample; the full-scan acquisition mode is used to acquire primary mass spectrometry data of ions of different abundances in the plastic consumer product sample; and the target data-dependent acquisition mode is used to acquire secondary mass spectrometry data of the remaining ions after removing duplicate ions that have already obtained secondary mass spectrometry data in the iterative data-dependent acquisition mode, based on the pre-identified ion list.

[0010] Preferably, the step of identifying substances based on the mass spectrometry data to obtain perfluorinated compound identification results includes: Based on the secondary mass spectrometry data obtained by the iterative data-dependent acquisition mode and the primary mass spectrometry data obtained by the full scan acquisition mode, suspected perfluorinated compound ions are screened and a pre-identified ion list is generated. Based on the pre-identified ion list, the target data-dependent acquisition mode is driven to acquire the secondary mass spectrometry data of the remaining ions in the pre-identified ion list after removing the ions that have already obtained secondary mass spectrometry data in the iterative data-dependent acquisition. Based on the secondary mass spectrometry data obtained from the iterative data-dependent acquisition mode and the target data-dependent acquisition mode, perfluorinated compounds in plastic consumer products are identified, and the perfluorinated compound identification results are obtained.

[0011] Furthermore, the process of screening suspected perfluorinated compound ions and generating a pre-identified ion list based on the secondary mass spectrometry data obtained from the iterative data-dependent acquisition mode and the primary mass spectrometry data obtained from the full-scan acquisition mode includes: The secondary mass spectrometry data acquired by the iterative data-dependent acquisition mode are matched with the secondary perfluorinated compound database to determine the ions for which secondary mass spectrometry data has been obtained; The primary mass spectrometry data acquired in the full-scan acquisition mode are matched with a primary perfluorinated compound database to screen out suspected perfluorinated compound ions. Ions for which secondary mass spectrometry data has been obtained through the iterative data-dependent acquisition mode are removed from the suspected perfluorinated compound ions, and a pre-identified ion list is generated. The pre-identified ion list is used to drive the target data-dependent acquisition mode to acquire secondary mass spectrometry data for the corresponding ions.

[0012] Optionally, matching the primary mass spectrometry data acquired in the full-scan acquisition mode with the primary perfluorinated compound database includes: The primary mass spectrometry data acquired in the full scan acquisition mode are matched with the primary perfluorinated compound database using the molecular formula search function or the suspect list matching function in the mass spectrometry analysis software.

[0013] Specifically, the step of driving the target data-dependent acquisition mode to acquire the secondary mass spectrometry data of each ion in the pre-identified ion list based on the pre-identified ion list includes: Using the pre-identified ion list as a trigger, during the analysis of the test solution using liquid chromatography-tandem mass spectrometry, ions with preset mass-to-charge ratio and retention time information are collected within the chromatographic retention time window corresponding to each ion in the pre-identified ion list, thereby obtaining the secondary mass spectrometry data of each ion in the pre-identified ion list.

[0014] Specifically, the identification of perfluorinated compounds in the plastic consumer products based on secondary mass spectrometry data of all ions, and the resulting perfluorinated compound identification results include: Based on all mass spectrometry data of all ions, a progressive judgment method from low to high is adopted. Under the premise of meeting the conditions of the lower identification level, the requirements of the higher identification level are gradually met, and finally the identification confidence level is determined.

[0015] Preferably, the primary perfluorinated compound database is obtained through the following method: acquiring perfluorinated compound information through literature retrieval and importing the Chinese names, chemical formulas, chemical substance registration numbers, and simplified molecular linear input canonical expressions from the perfluorinated compound information into PCDL workstation software to obtain the primary perfluorinated compound database; and / or The secondary perfluorinated compound database is obtained as follows: secondary mass spectrometry data of perfluorinated compound standards are acquired using the target data-dependent acquisition mode, the acquired secondary mass spectra are imported into the PCDL workstation software, and supplemented by the MS-Dial open-source secondary mass spectrometry database of perfluorinated compounds to obtain the secondary perfluorinated compound database.

[0016] This application has at least the following beneficial effects: The proposed scheme employs a collaborative acquisition strategy. First, it uses an iterative data-dependent acquisition mode to rapidly capture secondary mass spectrometry data of high-abundance ions, ensuring efficient identification of major perfluorinated compound components. Then, a full-scan acquisition mode is used to comprehensively record primary mass spectrometry information of all detectable ions, effectively identifying ions with perfluorinated compound characteristics that may have been missed in the first round of acquisition. Finally, based on the pre-identified ion list generated from the results of the first two rounds, the target data-dependent acquisition mode is driven to accurately trigger the acquisition of secondary spectra of suspected low-abundance ions, significantly improving the detection capability of novel perfluorinated compounds. Furthermore, this application automatically matches and filters the full scan data through a primary perfluorinated compound database, generates a pre-identified ion list using a preset matching threshold, and achieves standardized and automated screening of suspected target ions. Based on the pre-identified ion list, it directionally acquires secondary mass spectra of specific ions within the corresponding chromatographic retention time window, effectively avoiding acquisition failures caused by collision energy mismatch, trigger logic limitations, or time window deviations in traditional acquisition methods. This significantly improves the success rate and quality of acquiring secondary spectra of low-abundance ions. At the same time, through multi-level data matching and cross-validation, it reduces the systematic error and random error of a single algorithm, thereby improving the overall reliability and confidence of compound identification results. Furthermore, the primary perfluorinated compound database can be constructed based on literature retrieval and research, covering various identification information of compounds; the secondary perfluorinated compound database is constructed by target data-dependent collection of standards and supplemented by an open-source secondary mass spectrometry database to improve the consistency between spectra and instrument conditions and the database coverage; this application expands the screening scope of suspected compounds and improves the accuracy of spectrum matching by combining the primary and secondary perfluorinated compound databases, providing a solid data foundation for the reliable identification of perfluorinated compounds.

[0017] This application proposes a non-targeted identification method for perfluorinated compounds in plastic consumer products, which integrates the advantages of multiple mass spectrometry acquisition modes. It can take into account the identification needs of perfluorinated compounds with different abundances, improve the ability to detect suspicious signals, realize the identification of emerging perfluorinated compounds in complex matrix backgrounds, and reduce the risk of missed detection in conventional screening methods, thereby providing technical support for the safety evaluation of plastic consumer products. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1A schematic diagram of a non-targeted identification method for perfluorinated compounds in plastic consumer products; Figure 2 A schematic diagram illustrating the specific process of a non-targeted identification method for perfluorinated compounds in plastic consumer products; Figure 3 A flowchart illustrating the process of collecting non-targeted combination information; Figure 4 This is a schematic diagram of a method for pre-treating samples of plastic consumer products. Figure 5 This is a schematic diagram of a method for obtaining perfluorinated compound identification results based on mass spectrometry data; Figure 6 A schematic diagram of a method for screening suspected perfluorinated compound ions and generating a pre-identified ion list based on primary mass spectrometry data obtained in full-scan acquisition mode; Figures 7(a) and 7(b) are schematic diagrams of the results of non-targeted screening of perfluorinated compounds in plastic consumer products. Figure 7(a) is a schematic diagram of the screening results using a conventional data-dependent acquisition mode, and Figure 7(b) is a schematic diagram of the screening results using the non-targeted identification method for perfluorinated compounds in plastic consumer products provided in the embodiments of this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] Various embodiments of this application will be described more fully below. This application may have various embodiments, and adjustments and changes may be made therein. However, it should be understood that there is no intention to limit the various embodiments of this application to the specific embodiments disclosed herein, but rather this application should be understood to cover all adjustments, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of this application.

[0022] In the following, the terms “comprising” or “may include” as used in the various embodiments of this application indicate the presence of the disclosed functions, operations, or elements, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in the various embodiments of this application, the terms “comprising,” “having,” and their cognates are intended only to indicate a particular feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or the possibility of adding one or more combinations of features, numbers, steps, operations, elements, components, or combinations of the foregoing.

[0023] In various embodiments of this application, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0024] The terms used in the various embodiments of this application (such as "first," "second," etc.) may modify various constituent elements in the various embodiments, but do not limit the corresponding constituent elements. For example, the above terms do not limit the order and / or importance of the elements. The above terms are only used for the purpose of distinguishing one element from other elements. For example, a first user device and a second user device refer to different user devices, although both are user devices. For example, without departing from the scope of the various embodiments of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0025] It should be noted that, in this application, unless otherwise explicitly specified and defined, terms such as "installation," "connection," and "fixation" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] In this application, those skilled in the art should understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings and are only for the purpose of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0027] The terminology used in the various embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. The terms (such as those defined in a generally used dictionary) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0028] Currently, domestic standards for the detection of perfluorinated compounds in plastic consumer products mainly rely on targeted analysis, that is, the use of liquid chromatography-tandem mass spectrometry (LC-MS) technology to quantitatively detect regulated traditional perfluorinated compounds such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS).

[0029] Because this method relies on standards, it can no longer meet the current needs for detecting and screening thousands of emerging perfluorinated compounds. Targeted analysis cannot identify other emerging perfluorinated compounds with unknown structures that are outside the target compound range. This makes it impossible to keep track of whether emerging perfluorinated compounds are added during the production of plastic products in a timely manner. Moreover, the various chemicals added during the production of plastic consumer products constitute a complex matrix background. The complex matrix background will produce a strong shielding effect and increase background noise. Furthermore, there may be concentration differences of several orders of magnitude between perfluorinated compounds and coexisting additives. This will cause the signal of trace perfluorinated compounds to be submerged by the signal of high-concentration additives. As a result, the effective data coverage of non-targeted screening based on conventional data-dependent data acquisition mode is greatly reduced, which will cause significant interference to conventional non-targeted analysis methods.

[0030] Therefore, there is an urgent need to introduce non-targeted screening based on high-resolution mass spectrometry as a better solution for screening perfluorinated compounds in plastics, so as to overcome the interference of complex matrix background in plastic products on the accurate identification of perfluorinated compounds.

[0031] This application proposes a non-targeted identification method for perfluorinated compounds (PFOCs) in plastic consumer products. It addresses the limitations of current standard analytical methods for PFOCs in the field of additive screening for plastic consumer products, improving upon conventional methods' difficulty in achieving high-throughput screening of emerging PFOCs and overcoming the significant background interference from the plastic product matrix. It also reduces the risk of missed detection of low-abundance substances in conventional non-targeted screening and is suitable for non-targeted identification of PFOCs in plastic consumer products. Based on similar analytical principles, after adaptation to pretreatment conditions and mass spectrometry acquisition parameters, this method can also be extended to the screening of PFOCs in textiles, coating materials, and paper food contact materials.

[0032] Please see Figures 1-3 The non-targeted identification method for perfluorinated compounds in plastic consumer products proposed in this application specifically includes: S100: Pretreatment of plastic consumer product samples to obtain the test solution.

[0033] S200: The test solution is analyzed by liquid chromatography-tandem mass spectrometry, and a collaborative acquisition strategy including iterative data-dependent acquisition mode, full scan acquisition mode and target data-dependent acquisition mode is executed to obtain mass spectrometry data.

[0034] Specifically, the collaborative acquisition strategy includes: first, performing multiple iterations of data-dependent acquisition mode (Iterative DDA) on the test solution; then, performing one full scan acquisition mode (Full Scan) on the test solution; finally, generating a pre-identified ion list based on the identification results of the data acquired in the full scan acquisition mode; removing duplicate ions in the pre-identified ion list that have already obtained secondary mass spectrometry data through the iterative data-dependent acquisition mode; and then applying the target data-dependent acquisition mode (Target DDA) to the test solution.

[0035] The iterative data-dependent acquisition mode is used to acquire secondary mass spectrometry data of high-abundance ions in plastic consumer product samples; the full-scan acquisition mode is used to acquire primary mass spectrometry data of ions with different abundances in plastic consumer product samples; and the target data-dependent acquisition mode is used to acquire secondary mass spectrometry data of the remaining ions after removing duplicate ions that have already acquired secondary mass spectrometry data in the iterative data-dependent acquisition mode, based on a pre-identified ion list.

[0036] It should be noted that the method proposed in this application can define high-abundance ions and low-abundance ions based on the absolute response ranking of ions in the primary spectrum. Specifically, ions for which secondary mass spectrometry data are acquired through iterative data-dependent acquisition mode are all acquired ions and can be defined as high-abundance ions, while ions without secondary mass spectrometry data can be defined as unacquired low-to-medium abundance ions. In an optional implementation, the method proposed in this application performs three iterations of data-dependent acquisition mode on the test solution.

[0037] It should also be noted that primary mass spectrometry data and primary spectra are essentially the same type of data, differing only in their form of representation. Primary mass spectrometry data refers to the precursor ion signal directly acquired by a mass spectrometer under collision-free induced dissociation conditions. When primary mass spectrometry data is presented graphically, it forms what is commonly known as a primary spectrum. In other words, a primary spectrum is a visual representation of primary mass spectrometry data, and both have the same substantive content in data processing, database matching, and substance identification.

[0038] S300: Based on mass spectrometry data, it identifies substances and obtains results for the identification of perfluorinated compounds.

[0039] Specifically, please see Figure 4 Step S100 includes: S110: Cut the plastic consumer product sample into several block-shaped test specimens of the same specification.

[0040] S120: The block sample is subjected to ultrasonic-assisted extraction using a solvent to obtain an extract.

[0041] S130: The extract is subjected to nitrogen blowing concentration, volume adjustment and membrane filtration in sequence to obtain the test solution.

[0042] Specifically, please see Figure 5 Step S300 includes: S310: Based on the secondary mass spectrometry data obtained by the iterative data-dependent acquisition mode and the primary mass spectrometry data obtained by the full scan acquisition mode, suspected perfluorinated compound ions are screened and a pre-identified ion list is generated.

[0043] S320: Based on the pre-identified ion list, drive the target data-dependent acquisition mode to acquire the secondary mass spectrometry data of the remaining ions in the pre-identified ion list after removing the ions that have already obtained secondary mass spectrometry data in the iterative data-dependent acquisition.

[0044] S330: Based on the secondary mass spectrometry data obtained by the iterative data-dependent acquisition mode and the target data-dependent acquisition mode, perfluorinated compounds in plastic consumer products are identified to obtain perfluorinated compound identification results.

[0045] Preferably, the method proposed in this application embodiment can use at least two independent processing paths based on different data processing platforms or matching algorithms to perform feature extraction and database matching on the secondary mass spectrometry data respectively, and comprehensively compare the results of each path to select the matching results that meet the preset confidence conditions in at least one path, and generate the identification result of perfluorinated compounds in the sample to be tested based on the matching results.

[0046] Specifically, please see Figure 6 Step S310 includes: S311: Match the secondary mass spectrometry data acquired by the iterative data-dependent acquisition mode with the secondary perfluorinated compound database to determine the ions for which secondary mass spectrometry data has been obtained.

[0047] S312: Match the primary mass spectrometry data acquired in the full scan acquisition mode with the primary perfluorinated compound database to screen and obtain suspected perfluorinated compound ions.

[0048] S313: Remove ions from the suspected perfluorinated compound ions that have already obtained secondary mass spectrometry data through the iterative data-dependent acquisition mode, and generate a pre-identified ion list. The pre-identified ion list is used to drive the target data-dependent acquisition mode to acquire secondary mass spectrometry data of the corresponding ions.

[0049] In this embodiment, step S312 can use the molecular formula search function or the suspect list matching function in the mass spectrometry analysis software to match the primary mass spectrometry data acquired in the full scan acquisition mode with the primary perfluorinated compound database. Therefore, step S320 includes: using the pre-identified ion list as a trigger, during the analysis of the test solution using liquid chromatography-tandem mass spectrometry, ions with preset mass-to-charge ratios and retention times are acquired within the chromatographic retention time window corresponding to each ion in the pre-identified ion list, to obtain the secondary mass spectrometry data of each ion in the pre-identified ion list.

[0050] Based on this, step S330 can use all mass spectrometry data of all ions to adopt a progressive judgment method from low to high, and gradually meet the judgment requirements of higher levels while meeting the conditions of lower identification levels, and finally determine the identification confidence level.

[0051] For example, the identification confidence level of mass spectrometry data can be divided into five levels. Level 5 represents the ion of interest obtained solely based on the precise mass number of the first-stage mass spectrometry, lacking further structural information and thus having the lowest confidence level. Level 4 represents the ion whose molecular formula can be determined based on the first-stage mass spectrometry data, but whose specific structure cannot yet be reliably annotated. Level 3 represents the analyte whose candidate structure, candidate substituents, or candidate category can be provisionally annotated based on the precise mass number, isotope distribution, characteristic fragment ions, and / or homologue patterns. Level 2 represents the analyte that has not passed standard verification, but whose second-stage mass spectrometry has a high degree of matching with the database, and whose structure can be annotated with a high degree of confidence by combining evidence such as retention time patterns and homologue distribution patterns. Level 1 represents the analyte that has passed standard verification, meaning that the retention time, first-stage mass spectrometry, and second-stage mass spectrometry of the analyte are all consistent with the standard, and thus has the highest confidence level.

[0052] Optionally, the primary perfluorinated compound database is obtained as follows: information on perfluorinated compounds is obtained through literature retrieval and survey, and the Chinese names, chemical formulas, chemical substance registration numbers, and simplified molecular linear input canonical expressions of the perfluorinated compounds are imported into the PCDL workstation software (Agilent MassHunter PCDL manager) to obtain the primary perfluorinated compound database.

[0053] Optionally, the secondary perfluorinated compound database is obtained by: acquiring secondary mass spectrometry data of perfluorinated compound standards using the target data-dependent acquisition mode, importing the acquired secondary mass spectra into the PCDL workstation software, and supplementing it with the publicly available secondary mass spectrometry database of perfluorinated compounds from MS-Dial to obtain the secondary perfluorinated compound database.

[0054] It should be noted that the fragment ion spectrum obtained based on the target data-dependent acquisition mode... Figure 2 Secondary mass spectrometry (MS / MS) data can be identified by matching the MS / MS data with a secondary perfluorinated compound database, or by using spectral analysis of the MS / MS data for assisted identification. The process of matching the MS / MS data with the secondary perfluorinated compound database is similar to the process of processing data obtained through iterative data-dependent acquisition.

[0055] Those skilled in the art will understand that, in addition to the above-mentioned method of constructing a secondary perfluorinated compound database using PCDL workstation software, other commercial or open-source mass spectrometry databases, such as the MS-Dial supporting open-source database, can also be used as supplementary sources for the secondary mass spectrometry database. The data format conversion or import methods between different database platforms can be adjusted according to the actual software functions, without affecting the implementation of the core identification logic of this method. The PCDL workstation is used as an example in the embodiments of this application, but it does not constitute the only limitation on the database construction tool.

[0056] In an optional implementation, this method can use the open-source software MS-Dial (version 5.3) to extract ion features from the raw file containing secondary mass spectrometry data. The ion feature extraction parameters can be set to MS1 tolerance of 0.01 Da, MS2 tolerance of 0.025 Da, peak height threshold of 1000, mass slice width of 0.1, and addendum ion of [MH]-. Subsequently, the extracted ion features are matched and identified with an online secondary perfluorinated compound database. The matching parameters can be set to MS1 tolerance of 0.001 Da, MS2 tolerance of 0.005 Da, and fragment matching number ≥ 2, thereby identifying ion features that meet the matching parameter conditions as perfluorinated compound candidates. Correspondingly, this method can also utilize the Mass Hunter Qualitative Analysis (Version 10.0) workstation to extract ion features from data files containing secondary mass spectrometry data using the compound exploration - automatic MS / MS search function. The ion feature extraction parameters can be set to a retention time window of 0.25 min, a positive and negative MS / MS TIC threshold of 1000, and a mass matching tolerance of 0.05 Da. The extracted ion features are then matched and identified against a local secondary perfluorinated compound database, with the ion carrier set to a negative ion charge carrier (…). H), the standard mass tolerance for retrieval is 5 ppm, the database retrieval score is composed of mass fraction (100.00), isotope abundance fraction (60.00), and isotope difference fraction (50.00), the spectral library retrieval is set with an exact mass tolerance of ±10.0 ppm for pre-ion and ±15.0 ppm for fragment ion, and the matching source is limited to database (DB-Lib / Lib) retrieval, thereby identifying ion characteristics that meet the requirements of ≥2 fragment matching and ≥70 points as perfluorinated compound candidates.

[0057] Specifically, the method proposed in this application can obtain a data file containing all detectable ion primary mass spectrometry information and corresponding chromatographic retention times through full-scan acquisition mode. Then, using the "Find by Formula" (FBF) function in Agilent mass spectrometry analysis software (version 10.0), the data file is matched with the previously constructed primary perfluorinated compound database. The matching score weight can be set to a mass fraction of 100.00, an isotope abundance fraction of 60.00, and an isotope difference fraction of 50.00, thereby retaining matching results with a matching degree score ≥70. After removing duplicate perfluorinated compound candidate ions identified in the iterative data-dependent acquisition step, the remaining ion characteristics are summarized into a pre-identified ion list of low-abundance perfluorinated compounds, and the mass-to-charge ratio (m / z) of the ions is recorded and the time information is retained.

[0058] Ultimately, the method proposed in this application can comprehensively consider all analytical evidence, including whether the candidate perfluorinated compound has been verified by standards, whether it has obtained high-resolution matching of a secondary spectral library, whether it has a reasonable retention time pattern of homologues, and whether it contains characteristic perfluorinated compound fragment ions, and assign a final identification confidence level to each identified candidate perfluorinated compound according to the aforementioned five-level identification confidence system.

[0059] Please refer to Figures 7(a) and 7(b). As shown in Figure 7(a), when analyzing the same sample using the conventional data-dependent acquisition mode, only two perfluorinated compounds were identified. However, as shown in Figure 7(b), after adopting the collaborative acquisition strategy proposed in this application, 20 perfluorinated compounds from 6 major categories can be screened and identified in the same sample. The above results show that, compared with the conventional data-dependent acquisition mode, the collaborative acquisition strategy proposed in this application significantly improves the detection types and coverage of perfluorinated compounds, and can more effectively identify emerging perfluorinated compounds in complex samples. In addition, existing targeted detection methods, such as "Detection Methods for Key Chemical Substances in Consumer Products Part 8: Perfluorooctane Sulfonic Acid (PFOS) and Perfluorooctanoic Acid (PFOA)" (GB / T 44165.8—2025), mainly target the detection of PFOS and PFOA, further illustrating that the method proposed in this application has significant advantages in terms of detection range and screening capability.

[0060] In one specific embodiment, 11 of the most common plastic materials were selected, including: polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene (PE), acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), polyamide (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyoxymethylene (POM), and polyphenylene ether (PPO). The method proposed in this application embodiment can first use ultrasonic-assisted solid-liquid extraction to extract organic pollutants from the plastic sample. The specific steps are as follows: cut the plastic sample into multiple 0.5×0.5cm cubes; weigh 100mg of each cube into a 15mL polypropylene tube using a weighing balance; add an appropriate amount of internal standard solution to the centrifuge tube; then add 4mL of chromatographic grade methanol; perform ultrasonic treatment at room temperature for 1 hour; transfer the supernatant to another clean container; and repeat the ultrasonic extraction process with methanol three times to ensure complete extraction of organic pollutants from the sample.

[0061] After combining the supernatants obtained from each ultrasonic extraction, the combined liquid is purged and concentrated under a nitrogen atmosphere, and the combined solution is brought to a final volume of about 1 mL with methanol. The solution is then filtered using a nylon needle filter with a pore size of 0.22 µm, and the filtrate is collected into a chromatographic injection vial to obtain a plastic sample extract that can be used as the sample to be tested in step S100. The user can store the plastic sample extract at a low temperature of -20°C.

[0062] The determination of perfluorinated compounds in the extract of plastic samples by liquid chromatography was performed using an Agilent 1290 Infinity ultra-high performance liquid chromatography (UHPLC) system. Specifically, a C18 UHPLC column (ACQUITYUPLC BEH C18, 1.7µm, 2.1×100mm) was used for chromatographic separation. The column temperature was maintained at 35℃. The mobile phase system consisted of mobile phase A, which was an aqueous solution containing 2mM ammonium acetate, and mobile phase B, which was a methanol solution containing 2mM ammonium acetate. The flow rate of the mobile phase was 0.2mL / min, and the injection volume was 5μL.

[0063] The specific time for a single rinsing test can be set to 25 min. Under the initial conditions and from 0 min to 1 min, the proportion of mobile phase B is maintained at 5%. From 1 min to 8 min, the proportion of mobile phase B increases linearly from 5% to 50%. From 8 min to 15 min, the proportion of mobile phase B increases linearly from 50% to 100%. From 15 min to 22 min, the proportion of mobile phase B is maintained at 100%. From 22 min to 25 min, the proportion of mobile phase B decreases from 100% to 5%, and column equilibration is performed.

[0064] Mass spectrometry detection was performed using an Agilent 6546 quadrupole time-of-flight high-resolution mass spectrometer. The ion source was an electrospray ionization (ESI) source, operating in negative ion mode. The operating parameters of the ion source were as follows: spray voltage set to 1000V, nebulizing gas pressure set to 25psi, drying gas flow rate set to 10L / min, drying gas temperature set to 300℃, sheath gas temperature set to 330℃, sheath gas flow rate set to 12L / min, and capillary voltage set to -3500V.

[0065] The mass spectrometer's data acquisition strategy specifically combines a composite strategy of Iterative Data Dependent Acquisition (IDA), Full Scan acquisition, and Target Data Dependent Acquisition (DDA).

[0066] In the iterative data-dependent acquisition mode, the first-level spectrum (MS1) data was acquired at a scan rate of 3 spectra / second, with the ion m / z range being 50-1000; the second-level spectrum (MS2) data was acquired at a scan rate of 2 spectra / second with a medium isolation width of approximately 4 m / z. A maximum of 2 precursor ions were selected for fragmentation in each acquisition cycle, with a mass error tolerance of 10 ppm and a retention time exclusion tolerance of ±0.2 minutes. The fragmentation collision energies of each selected ion were set to 10 eV, 20 eV, and 40 eV, respectively. In full-scan acquisition mode, primary spectrum data are acquired at a scan rate of 3 spectra / second, with ion m / z range of 50-1000.

[0067] In the target data-dependent acquisition mode, primary spectral data is acquired at a scan rate of 3 spectra / second, with ion m / z ranging from 50 to 1000. Secondary spectral data is acquired at a scan rate of 2 spectra / second with a moderate isolation width of approximately 4 m / z, acquiring target ions with preset mass-to-charge ratio and retention time information. The mass error tolerance is set to 10 ppm, the retention time exclusion tolerance is ±1.0 minute, and the fragmentation collision energies of each selected ion are set to 10 eV, 20 eV, and 40 eV, respectively.

[0068] The non-targeted identification method for perfluorinated compounds in plastic consumer products proposed in this application abandons the traditional single data-dependent acquisition (DDA) mode and integrates three acquisition modes: iterative data-dependent acquisition mode, full-scan acquisition mode, and target data-dependent acquisition mode, to achieve precise coverage of perfluorinated compounds of different abundances. Specifically, it uses the iterative data-dependent acquisition mode to capture high-abundance signals, and the full-scan acquisition mode to unbiasedly screen for medium- and low-abundance signals, providing a data foundation for further analysis and identification of secondary spectra, thereby achieving stable secondary mass spectrometry acquisition of perfluorinated compound ions with a high dynamic range.

[0069] Meanwhile, this application's embodiments employ a hierarchical and progressive data analysis process. A matching hierarchical data processing workflow is designed for the acquired multidimensional data. For high-abundance compounds, automated spectral library matching can be performed using software such as MS-Dial and MassHunter to achieve efficient identification. For medium- and low-abundance suspicious signals in the full-scan acquisition mode, molecular formula lookup (FBF) technology based on primary ion information mining can be used in MassHunter software, combined with a preset primary local database of perfluorinated compounds, to generate a pre-identified ion list. This significantly improves the detection capability of suspicious signals. The pre-identified ion list is then used as a trigger list and fed back to the mass spectrometer for target data-dependent acquisition model acquisition. This forces the acquisition of MS2 fragmentation spectra of all suspicious MS1 precursor ions in the list, realizing a closed-loop analysis from initial suspicion to obtaining confirmatory secondary mass spectrometry evidence for medium- and low-abundance perfluorinated compounds, reducing the risk of missed detection in conventional screening methods.

[0070] Therefore, this application can identify emerging low-to-medium abundance perfluorinated compounds that are easily overlooked under conventional data-dependent acquisition modes, making the identification results more comprehensive and closer to the true composition of perfluorinated compound contamination in the sample. At the same time, the identification of high-abundance ions can still be efficiently completed by combining this method with automated data processing workflows, and supplementary acquisition of suspected ions for which secondary mass spectrometry data was not obtained can be performed through target data-dependent acquisition modes, thereby improving the detection rate while ensuring data processing efficiency and identification accuracy.

[0071] In summary, the proposed solution in this application is a comprehensive technical approach, from sample preparation to confirmatory analysis, designed to address the challenge of screening trace and emerging perfluorinated compounds in plastic consumer products. Its key application-oriented aspects are as follows: (1) Systematic process for plastic matrix: This application constructs a complete workflow from “acquisition and preparation of representative plastic samples” to “on-machine detection” and then to “compound identification”. The method has the universality and stability for non-target screening of common plastic materials and can cover 11 types of plastic materials such as polypropylene and polyvinyl chloride, ensuring that it can be stably applied to detect a variety of perfluorinated compounds on different plastic matrices.

[0072] (2) Multi-dimensional data acquisition strategy: This application abandons the traditional single data-dependent acquisition mode and integrates the iterative data-dependent acquisition mode, the full scan acquisition mode and the target data-dependent acquisition mode in a coordinated manner. It achieves secondary mass spectrometry data coverage for perfluorinated compounds of different abundances, uses the iterative data-dependent acquisition mode to capture high-abundance signals, uses the full scan acquisition mode to unbiasedly screen medium and low-abundance signals, and provides a data basis for further acquisition of secondary spectra for analysis, identification and confirmation, thereby achieving stable acquisition of secondary mass spectrometry of perfluorinated compound ions with high dynamic range.

[0073] (3) Layered and progressive data analysis process: For the above multidimensional data, this application designed a matching layered data processing workflow. Among them, MS-Dial and MassHunter software were used for automated spectral library matching for high-abundance compounds to achieve efficient identification. For medium and low-abundance suspicious signals in the full scan acquisition mode, molecular formula search (FBF) technology based on primary ion information mining was used, combined with the preset primary local database of perfluorinated compounds, to generate a "pre-identification list", thereby significantly improving the ability to detect suspicious signals.

[0074] (4) Closed-loop verification mechanism from “suspected discovery” to “confirmation”: This application uses the above-mentioned “pre-identification list” as a trigger list and feeds it back to the mass spectrometer for target data-dependent acquisition. It can force the acquisition of MS2 fragmentation spectra of all suspicious MS1 precursor ions in the list, realizing closed-loop analysis from initial suspicion to obtaining confirmatory secondary mass spectrometry evidence for low- and medium-abundance perfluorinated compounds, reducing the risk of missed detection in conventional screening methods.

[0075] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A non-targeted identification method for perfluorinated compounds in plastic consumer products, characterized in that, The method includes: The plastic consumer product sample was pretreated to obtain the test solution; The test solution was analyzed by liquid chromatography-tandem mass spectrometry, and a collaborative acquisition strategy including iterative data-dependent acquisition mode, full scan acquisition mode and target data-dependent acquisition mode was executed to obtain mass spectrometry data; Based on the mass spectrometry data, substance identification was performed to obtain the identification results of perfluorinated compounds.

2. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 1, characterized in that, The pretreatment of the plastic consumer product sample to obtain the test solution includes: The plastic consumer product sample was cut into several block-shaped samples of the same specification; The block sample was subjected to ultrasonic-assisted extraction with a solvent to obtain an extract. The extract was subjected to nitrogen blowing concentration, volume adjustment and membrane filtration in sequence to obtain the test solution.

3. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 1, characterized in that, The collaborative acquisition strategy includes: First, the iterative data-dependent acquisition mode is performed multiple times on the test liquid; The full scan acquisition mode was then performed once on the test liquid; Finally, a pre-identified ion list is generated based on the identification results of the data acquired in the full-scan acquisition mode. After removing duplicate ions in the pre-identified ion list that have already obtained secondary mass spectrometry data through the iterative data-dependent acquisition mode, the target data-dependent acquisition mode is applied to the test solution.

4. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 3, characterized in that, The iterative data-dependent acquisition mode is used to acquire secondary mass spectrometry data of high-abundance ions in the plastic consumer product sample; the full-scan acquisition mode is used to acquire primary mass spectrometry data of ions of different abundances in the plastic consumer product sample; the target data-dependent acquisition mode is used to acquire secondary mass spectrometry data of the remaining ions after removing duplicate ions whose secondary mass spectrometry data has been obtained by the iterative data-dependent acquisition mode, based on the pre-identified ion list.

5. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 1, characterized in that, The process of identifying substances based on the mass spectrometry data to obtain perfluorinated compound identification results includes: Based on the secondary mass spectrometry data obtained by the iterative data-dependent acquisition mode and the primary mass spectrometry data obtained by the full scan acquisition mode, suspected perfluorinated compound ions are screened and a pre-identified ion list is generated. Based on the pre-identified ion list, the target data-dependent acquisition mode is driven to acquire the secondary mass spectrometry data of the remaining ions in the pre-identified ion list after removing the ions that have already obtained secondary mass spectrometry data in the iterative data-dependent acquisition. Based on the secondary mass spectrometry data obtained from the iterative data-dependent acquisition mode and the target data-dependent acquisition mode, perfluorinated compounds in plastic consumer products are identified, and the perfluorinated compound identification results are obtained.

6. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 5, characterized in that, The screening of suspected perfluorinated compound ions and the generation of a pre-identified ion list based on the secondary mass spectrometry data obtained by the iterative data-dependent acquisition mode and the primary mass spectrometry data obtained by the full-scan acquisition mode include: The secondary mass spectrometry data acquired by the iterative data-dependent acquisition mode are matched with the secondary perfluorinated compound database to determine the ions for which secondary mass spectrometry data has been obtained; The primary mass spectrometry data acquired in the full-scan acquisition mode are matched with a primary perfluorinated compound database to screen out suspected perfluorinated compound ions. Ions for which secondary mass spectrometry data has been obtained through the iterative data-dependent acquisition mode are removed from the suspected perfluorinated compound ions, and a pre-identified ion list is generated. The pre-identified ion list is used to drive the target data-dependent acquisition mode to acquire secondary mass spectrometry data for the corresponding ions.

7. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 6, characterized in that, The step of matching the primary mass spectrometry data acquired in the full-scan acquisition mode with the primary perfluorinated compound database includes: The primary mass spectrometry data acquired in the full scan acquisition mode are matched with the primary perfluorinated compound database using the molecular formula search function or the suspect list matching function in the mass spectrometry analysis software.

8. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 7, characterized in that, The step of obtaining the secondary mass spectrometry data of the remaining ions in the pre-identified ion list after removing ions that have already obtained secondary mass spectrometry data in the iterative data-dependent acquisition based on the pre-identified ion list and driving the target data-dependent acquisition mode includes: Using the pre-identified ion list as a trigger, during the analysis of the test solution using liquid chromatography-tandem mass spectrometry, ions with preset mass-to-charge ratio and retention time information are collected within the chromatographic retention time window corresponding to each ion in the pre-identified ion list, thereby obtaining the secondary mass spectrometry data of each ion in the pre-identified ion list.

9. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 8, characterized in that, The secondary mass spectrometry data obtained based on the iterative data-dependent acquisition mode and the target data-dependent acquisition mode are used to identify perfluorinated compounds in plastic consumer products, and the perfluorinated compound identification results include: Based on all mass spectrometry data of all ions, a progressive judgment method from low to high is adopted. Under the premise of meeting the conditions of the lower identification level, the requirements of the higher identification level are gradually met, and finally the identification confidence level is determined.

10. The non-targeted identification method for perfluorinated compounds in plastic consumer products according to claim 6, characterized in that, The primary perfluorinated compound database was obtained through the following methods: information on perfluorinated compounds was acquired through literature retrieval and research; and the Chinese names, chemical formulas, chemical substance registration numbers, and simplified molecular linear input canonical expressions of the perfluorinated compounds were imported into the PCDL workstation software to obtain the primary perfluorinated compound database; and / or The secondary perfluorinated compound database is obtained as follows: secondary mass spectrometry data of perfluorinated compound standards are acquired using the target data-dependent acquisition mode, the acquired secondary mass spectra are imported into the PCDL workstation software, and supplemented by the publicly available secondary mass spectrometry database of perfluorinated compounds from MS-Dial to obtain the secondary perfluorinated compound database.

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