Sample treatment method for determining photoinitiator in packaging material

Abstract

The invention provides a sample treatment method for determining a photoinitiator in a packaging material, and belongs to the field of sample treatment and detection. The sample treatment method comprises the following steps: extracting a system consisting of a to-be-detected packaging material and an extracting agent in a medium collision extraction instrument, and then carrying out solid-liquid separation to obtain a to-be-detected sample solution; the extracting agent is methanol; the material-liquid ratio of the area of the sample to be detected to the volume of the extracting agent is 1-10cm < 2 > / mL; the linear speed of the medium collision extraction instrument is 4 m.s <-1 >-5.5 m.s <-1 >; in the extraction treatment process, a cracking medium is 1 / 4 inch cylindrical ceramic beads; the time of single extraction treatment is less than or equal to 60 seconds, and the total time of the extraction treatment process is 1-3 minutes; the photoinitiator is at least one of 2-methyl benzophenone, 3-methyl benzophenone, 4-isopropyl thioxanthone and biphenyl benzophenone. The photoinitiator is at least one of 2-methyl benzophenone, 3-methyl benzophenone, 4-isopropyl thioxanthone and biphenyl benzophenone. Based on the sample treatment method, the sample can be quickly treated, the sample extraction rate is improved, and the condition of missing detection is avoided.

Description

[0001] This invention is a divisional application of Chinese invention patent application No. 202110390487.9, filed on April 12, 2021, entitled "A method for preparing and detecting a sample of photoinitiator in packaging materials". Technical Field

[0002] This invention relates to the field of sample processing and testing, and more particularly to a sample processing method for determining photoinitiators in packaging materials. Background Technology

[0003] Paper packaging is currently the most widely used food packaging material. It is inexpensive, has low processing costs, and is convenient for both production and decoration, as well as storage and transportation.

[0004] Food packaging materials have a significant impact on product safety, and attention must be paid to the potential hazards they pose to products, especially their impact on human health.

[0005] Photoinitiators, also known as photocuring agents, are compounds that can initiate the polymerization, cross-linking, and curing of monomers, and are a major component of printing inks. When harmful photoinitiators are used in printing inks in food packaging materials, these photoinitiators can harm human health through contact and other means. Therefore, accurate testing of the photoinitiator content in packaging materials is necessary.

[0006] Traditional methods require samples to undergo a complex pretreatment process before chromatographic separation and detection, consuming significant manpower, solvents, and time. With the increasing number of samples in actual testing, achieving rapid and complete extraction of target analytes in a short time has remained a pressing issue for analytical researchers. Summary of the Invention

[0007] To address the shortcomings of existing methods for determining photoinitiators in packaging materials, this invention provides a sample processing method for determining photoinitiators in packaging materials. The aim is to provide a sample processing method that can quickly process samples, improve sample extraction rate, and avoid false negatives.

[0008] The present invention also provides a method for determining photoinitiators in packaging materials.

[0009] The composition of photoinitiators in packaging materials is complex, and many photoinitiators are present in low concentrations, resulting in low detection rates and a high likelihood of missed detections. Furthermore, packaging materials have a wetting and adsorption effect on photoinitiators, further increasing the probability of missed detections. To address this technical issue, industry standard methods are not only cumbersome but also struggle to avoid missed detections of certain photoinitiator components, leading to false negatives. This invention provides the following technical solution:

[0010] A sample preparation method for determining photoinitiators in packaging materials involves extracting the packaging material to be tested in a media collision extractor, followed by centrifugation to obtain the sample solution to be tested; the extractant is a single solvent or a miscible mixture of alcohol, acetone, acetonitrile, ester, and alkanes.

[0011] This invention has discovered that by combining extractants and pyrolysis extraction processes, it is possible to achieve simultaneous, rapid, and efficient extraction of photoinitiators from packaging materials. This helps to avoid missed detection of photoinitiator components and to prevent false negatives.

[0012] This invention reveals that the synergistic combination of extractant and pyrolysis extraction process is key to improving the extraction rate of photoinitiators in test samples and reducing false negatives. The study also found that combined control of the type of pyrolysis medium, extractant composition, and extraction procedure helps to further enhance the synergistic effect, improve the extraction efficiency of photoinitiators in test samples, reduce the missed detection of certain difficult-to-identify photoinitiators, and also improve the recovery rate, sensitivity, and other measurement effects.

[0013] In this invention, the alcohol is a C1 to C4 monool.

[0014] Preferably, the ester is a C3-C6 carboxylic acid ester.

[0015] Preferably, the alkane is C3-C4. 12 Alkanes or cycloalkanes.

[0016] Preferably, the extractant is a single solvent or a miscible mixture of methanol, ethanol, acetonitrile, acetone, n-hexane, and ethyl acetate.

[0017] Further optimization revealed that methanol was chosen as the extractant. Using methanol as the extractant provides better synergy with the extraction process, helping to improve the extraction efficiency of photoinitiators in the sample, reduce missed extraction rates, decrease false negatives, and further improve the recovery rate, sensitivity, and accuracy of subsequent assays.

[0018] In this invention, the material-to-liquid ratio of the sample (area) to the extractant (volume) is 1–10 cm³. 2 / mL; more preferably 4–6 cm2 / mL.

[0019] In this invention, the media collision extraction instrument is, for example, the FastPrep from MP Biomedicals. @ -24 instrument.

[0020] During the uniform grinding process, the pyrolysis medium used is at least one of medium S, medium M, or medium D; wherein, medium S is a 1 / 8-inch stainless steel bead; medium M is a 1 / 4-inch cylindrical ceramic bead; and medium D is a 1.4 mm ceramic bead.

[0021] Preferably, the pyrolysis medium used is medium M.

[0022] Preferably, the linear velocity of the extractor is 4 m / s. -1 ~6.5m·s -1 .

[0023] In this invention, the time for a single pyrolysis extraction process is less than or equal to 60 seconds; the total time for the extraction process is 1 to 3 minutes.

[0024] In this invention, the photoinitiator is at least one selected from 2-hydroxy-2-methyl-1-phenylpropanone, methyl benzoylcarbamate, benzophenone, 2-methylbenzophenone, 1-hydroxycyclohexylphenyl ketone, ethyl p-N,N-dimethylaminobenzoate, 3-methylbenzophenone, 4-methylbenzophenone, 2,2-dimethoxy-2-phenylacetophenone, methyl o-benzoylbenzoate, isooctyl p-dimethylaminobenzoate, 2-methyl-1-(4-methylthio)phenyl-2-morpholino-1-propanone, 4-isopropylthioxanthonone, 2-isopropylthioxanthonone, biphenylbenzophenone, 2,4-diethylthioxanthonone, 4,4-bis(dimethylamino)benzophenone, and 4,4-bis(diethylamino)benzophenone.

[0025] Preferably, the photoinitiator comprises two or more of the photoinitiators, more preferably 18 of them. This invention enables the simultaneous extraction of up to 18 photoinitiators, avoiding missed extractions and helping to reduce false negatives.

[0026] In this invention, the packaging paper is various types of food packaging paper.

[0027] The sample preparation method of the present invention has a short extraction time, high extraction efficiency and low solvent consumption for extracting photoinitiators in food packaging materials, which can change the traditional pretreatment mode and method that mainly relies on extraction methods such as oscillation and ultrasound.

[0028] The present invention also provides a method for determining photoinitiators in packaging materials, wherein the test solution is prepared by the above method and then GC-MS is performed.

[0029] In this invention, the above-described process can be used for extraction, followed by centrifugation and membrane filtration to obtain the extract. The extract is then subjected to GC-MS analysis.

[0030] In this invention, the GC-MS determination conditions are as follows: a capillary column is used; the stationary phase is 5% phenyl / 95% methylpolysiloxane, with dimensions of [30m (length) × 0.25mm (inner diameter) × 0.25μm (film thickness)]; the injection port temperature is set to 300℃; the carrier gas is helium (purity ≥99.999%), with a constant flow rate of 1.0mL / min; the injection volume is 1μL, using split injection with a split ratio of 40:1; the temperature program is as follows: initial temperature 70℃, increasing to 300℃ at a rate of 10℃ / min, holding for 5min, and then maintaining at 300℃ for 5min in the run mode. The mass spectrometer transfer line temperature is set to 300℃; electron impact ionization (EI) is used with an ionization energy of 70eV; the ion source temperature is set to 280℃; the quadrupole temperature is set to 150℃; and the solvent delay is 6min.

[0031] This invention allows for simultaneous batch pretreatment of multiple samples based on the characteristics of the adapter. The adapters used are primarily available in sizes of 48×2mL, 24×2mL, 24×4.5mL, 12×15mL, and 2×50mL. The adapter size is selected based on the required sample volume.

[0032] Beneficial effects:

[0033] 1. Addressing the unique characteristics and identification challenges of photoinitiators in packaging materials, this invention innovatively proposes a media collision extraction process. Building upon this, further control of the pyrolysis medium, extractant, and extraction procedure effectively improves the extraction efficiency of photoinitiators and reduces the rate of missed extraction. This method can rapidly and efficiently extract up to 18 photoinitiators from food packaging materials, significantly shortening pretreatment time (e.g., reducing treatment time to 1 minute), reducing the amount of extractant used, and eliminating the need for sample purification. The process is simple, efficient, and yields superior detection results, effectively reducing false negatives.

[0034] 2. Thanks to the innovative sample processing method described above, the technical solution of this invention can determine up to 18 photoinitiators in packaging materials, reducing false negatives. Moreover, it also helps to improve the recovery rate, sensitivity and accuracy of the determination. Attached Figure Description

[0035] Figure 1 The chromatograms of 18 photoinitiators and internal standard (deuterated anthracene) are shown.

[0036] Figure 2The results of photoinitiator tests using different extractants are shown (S5: n-hexane: ethyl acetate = 3:7; S8: acetonitrile: n-hexane: ethyl acetate = 20:9:21).

[0037] Figure 3 The test results of the traditional treatment method and the new treatment method are shown;

[0038] Figure 4 The chromatogram for detecting photoinitiators in biscuit packaging paper is shown;

[0039] Figure 5 The changes in paper samples before and after treatment with the new method are shown. Detailed Implementation

[0040] 1) Pretreatment condition optimization: Based on the hardness and thickness of food packaging materials, some pyrolysis media with greater impact force were selected for screening; based on the polarity and solubility of photoinitiators, different extractants were screened; in order to achieve the maximum extraction of photoinitiators, the pretreatment procedure was optimized and the processing time was minimized as much as possible; the impact of purification operation on test results was investigated to determine whether additional purification steps are needed.

[0041] 2) Conduct recovery rate experiments on 18 kinds of photoinitiators.

[0042] 3) GC-MS was used to detect the actual samples, and the results of the traditional and new processing methods were compared. Precision experiments were also conducted to further examine whether the new processing method meets the actual testing requirements.

[0043] In this case, unless otherwise stated, the media collision extraction instrument was manufactured by MP Biomedicals, model FastPrep. @ -twenty four.

[0044] In this invention, unless otherwise stated, the extraction time for a single extraction is 1 minute. When the extraction time is a multiple of 1 minute, it means that multiple extractions were performed, and the time interval between the multiple extractions is, for example, 1 to 2 minutes.

[0045] The traditional pretreatment method refers to the industry standard "YQ / T 31-2013 Determination of photoinitiators in cigarette packs and box packaging paper by gas chromatography-mass spectrometry".

[0046] Pretreatment method according to industry standard YQ / T 31-2013: Accurately cut a 10.0cm × 5.0cm sample. Cut the sample into fragments of approximately 0.5cm × 0.5cm. Place the fragmented sample in a 50mL stoppered Erlenmeyer flask, add 20mL of water, let stand for 30min, then add 20mL of acetonitrile and 200μL of internal standard solution (deuterated anthracene, 1mg / mL), sonicate for 40min, let stand for 5min, take 4mL of the supernatant and put it into a 15mL centrifuge tube, add 3mL of n-hexane-ethyl acetate solution, vortex at a linear speed of 500r / min for 5min, let stand, and take the supernatant for purification. Transfer (1.5±0.2) mL of the supernatant to a 2 mL centrifuge tube containing 150 mg of anhydrous magnesium sulfate, 50 mg of PSA and 50 mg of C18 adsorbent. Vortex at 500 r / min for 5 min, then centrifuge at 5000 r / min for 10 min. Take the supernatant for GC-MS analysis.

[0047] Example 1:

[0048] Preparation of internal standard solution of deuterated anthracene: Accurately weigh 100 mg of deuterated anthracene into a 100 mL volumetric flask, and dilute to volume with acetonitrile to obtain an internal standard solution with a concentration of 1 mg / mL. This solution can be stored in a refrigerator (4 °C) protected from light for two months.

[0049] Preparation of the working solution for the mixed standard curve of 18 photoinitiators: Accurately transfer 0.01 mL, 0.04 mL, 0.1 mL, 0.2 mL, 0.4 mL, 1.0 mL, and 2.0 mL of the mixed standard solution of 18 photoinitiators (100 μg / mL) into seven 10 mL volumetric flasks. Accurately transfer 40 μL of the above internal standard solution into each volumetric flask, and finally dilute to volume with acetonitrile. The concentrations of the prepared mixed standard solutions of 18 photoinitiators are 0.1, 0.4, 1.0, 2.0, 4.0, 10, and 20 μg / mL, respectively. The chromatographic separation chromatograms of the 18 photoinitiators and the internal standard (deuterated anthracene) are shown below. Figure 1 As shown.

[0050] GC-MS analysis was performed on a series of standard working solutions. The ratio of the quantitative ion peak area of ​​the photoinitiator to the internal standard in each standard working solution was plotted on the ordinate, and the content of the photoinitiator in each standard working solution was plotted on the abscissa to obtain standard working curves and regression coefficients (R) for 18 photoinitiators. The 18 photoinitiators showed good linearity in the range of 0.1–20 μg / mL, with correlation coefficients R0. 2 All values ​​were greater than 0.99. The detection limits of the test method were 0.06–0.18 mg / m³. 2 The limit of quantitation is 0.20–0.60 mg / m³. 2The result was much smaller than the value obtained using the industry standard method (the detection limit in the industry standard method YQ / T 31-2013 is 0.30~0.90mg / m³). 2 The limit of quantitation is 1.00–3.00 mg / m³. 2 The results are shown in Table 1, indicating that the method has higher sensitivity.

[0051] Table 1. Linear equations, correlation coefficients, limits of detection, and limits of quantitation for 18 photoinitiators.

[0052]

[0053] Example 2: Study of pyrolysis media

[0054] Initially, three pyrolysis media with significant impact forces were selected: media S, media M, and media D. Media S consisted of 1 / 8-inch stainless steel beads; media M consisted of 1 / 4-inch cylindrical ceramic beads; and media D consisted of 1.4 mm ceramic beads. A 10.0 cm × 5.0 cm sample was accurately cut and then further cut into approximately 0.5 cm × 0.5 cm fragments. These fragments were placed in 15 mL centrifuge tubes containing different types of pyrolysis media, respectively. 10 mL of extraction solvent (a 3:7 volume ratio mixture of n-hexane and ethyl acetate) and the internal standard deuterated anthracene were added. The media collision extraction process was performed for 4 m·s. -1 (Linear velocity), 1 min; centrifugation (4,000 rpm) for 2 min, the supernatant was filtered through a membrane and then analyzed by GC-MS. To compare the different test results after treatment with different pyrolysis media, an actual sample of cigarette box packaging paper a was tested, and the test results are shown in Table 2.

[0055] Table 2. Experimental results using different pyrolysis media.

[0056]

[0057] By comparing the above experimental results and the degree of damage to the packaging paper after treatment with different pyrolysis media, it was found that the paper sample was most thoroughly damaged when treated with medium M, and the test results were also the highest. Therefore, medium M was selected as the optimal pyrolysis medium for the experiment.

[0058] Example 3: Study on the extractant:

[0059] A sample of 10.0cm × 5.0cm was accurately cut from cigarette pack paper (b). The cut sample was then cut into fragments of approximately 0.5cm × 0.5cm and placed in a 15mL centrifuge tube containing lysis medium M. 10mL of the extractant and internal standard deuterated anthracene (as shown in the table below) were added, and the mixture was subjected to collision extraction for 4m·s. -1Centrifuge (4,000 rpm) for 1 min; then centrifuge for 2 min, and filter the supernatant through a membrane for GC-MS analysis. The test results using different extractants are shown in Table 3. The traditional processing method was performed according to the industry standard YQ / T 31-2013 "Determination of Photoinitiators in Cigarette Packaging Paper by Gas Chromatography-Mass Spectrometry," and the results were compared with those obtained using this method. Figure 2 This allows for a more intuitive understanding of the impact of using different extractants on the test results.

[0060] Table 3. Experimental results using different extractants.

[0061]

[0062] Note: 1) ND: Below the detection limit, its content cannot be determined;

[0063] 2) S5: n-hexane: ethyl acetate = 3:7;

[0064] 3) S8: Acetonitrile: n-hexane: ethyl acetate = 20:9:21.

[0065] The experimental results in the table above show that when extracting various photoinitiators from box packaging paper using different extractants, the test results vary due to the different polarities and solubilities of each photoinitiator. Overall, methanol is the optimal extractant for testing photoinitiators in box packaging paper. Subsequent comparison with the results from industry standard methods revealed that the test results for photoinitiators 4-MBP and 907 were similar, while the results for DETX and EHDBA obtained using the new treatment method were significantly better than those obtained using traditional methods. This suggests that some photoinitiators exist not only on the surface of the packaging box but also within the ink layer or polymer, and traditional ultrasonic pretreatment cannot extract them completely. For 2-ITX, DEAB, PBZ, and EDB, traditional methods suffer from false negatives and missed detections, while this new method can detect their content, demonstrating the advantages of the new method.

[0066] Example 4: Study of extraction processes, such as linear velocity and time

[0067] For the optimization experiment of the processing procedure, the experiment was conducted using boxed packaging paper b. The processing method was as follows: accurately cut a 10.0cm × 5.0cm sample, cut the sample into approximately 0.5cm × 0.5cm fragments, place them in a 15mL centrifuge tube containing lysis medium M, add 10mL of extraction solvent methanol and internal standard deuterated anthracene, and perform the medium collision extraction processing procedure according to the table below; centrifuge (4,000rpm) for 2min, collect the supernatant, filter the membrane, and perform GC-MS analysis. Table 4 shows that the processing speed (linear velocity, from 4m·s) was optimized. -1 →6.5m·s-1 The detection rate showed a slight decrease in the amount of photoinitiator detected, which was attributed to increased heat generation and photoinitiator degradation as the processing speed increased. Appropriate linear speed and time would help further improve the detection results.

[0068] Table 4. Experimental results of extraction treatment using different processing speeds and times.

[0069]

[0070] Example 5: Purification Experiment Study

[0071] To determine whether the new treatment method requires purification to reduce matrix interference, a comparative experiment was conducted. A packaging paper sample (c) was tested using both the industry standard method and the newly developed method (with and without purification). The new method was tested in parallel twice. The specific procedure was as follows: a 10.0cm × 5.0cm sample was accurately cut, and then cut into approximately 0.5cm × 0.5cm fragments. These fragments were placed in a 15mL centrifuge tube containing pyrolysis medium M, and 10mL of extraction solvent methanol and internal standard deuterated anthracene were added. The mixture was subjected to collision extraction for 4 m·s. -1 For purification treatment, add the following procedure: Transfer (1.5±0.2) mL of the supernatant to a 2 mL centrifuge tube containing 150 mg anhydrous magnesium sulfate, 50 mg PSA, and 50 mg C18 adsorbent. Vortex at 500 r / min for 5 min, centrifuge at 4,000 rpm for 2 min, filter the supernatant through a membrane, and perform GC-MS analysis. Table 5 shows a comparison of the test results for the industry standard method and the new method (with and without purification treatment). Figure 3 This allows for a more intuitive view of the differences between the industry standard method and the new treatment method (without purification) test results.

[0072] Table 5 Comparison of purification treatment experiments

[0073]

[0074] Note: ND: Below the detection limit, its content cannot be determined.

[0075] The experimental results in the table above show that the test results for most photoinitiators remained almost unchanged after purification treatment, while the test results for EHDBA decreased slightly. This is attributed to the selective adsorption of the purification agent. Therefore, the new treatment method eliminates the need for purification, saving both cost and time.

[0076] Example 6: Experimental Study on Recovery Rate

[0077] Subsequently, recovery experiments were conducted using a freshly prepared simulated sample (made by coating blank cardstock with ink mixed with photoinitiator and standard) and the optimized method. Specifically, a 10.0cm × 5.0cm sample was accurately cut, then further cut into approximately 0.5cm × 0.5cm fragments. These fragments were placed in a 15mL centrifuge tube containing pyrolysis medium M, and 10mL of extractant methanol and internal standard deuterated anthracene were added. The mixture was subjected to collision extraction for 4 m·s. -1 Centrifuge (4,000 rpm) for 1 min; then centrifuge for 2 min, and filter the supernatant through a membrane for GC-MS analysis. The results are shown in Table 6.

[0078] Table 6 Results of Recovery Rate Experiment

[0079]

[0080] As shown in the table above, when two levels of photoinitiator mixed solutions were added, the spiked recoveries of the 18 photoinitiators ranged from 85.7% to 120.3%, indicating that the developed method has high testing accuracy.

[0081] Example 7: Experimental Study on Sample Precision

[0082] A packaging paper sample d was tested using both the industry standard processing method and an optimized new processing method, with each test performed in triplicate. The new processing method involved accurately cutting a 10.0cm × 5.0cm sample into approximately 0.5cm × 0.5cm fragments, placing them in a 15mL centrifuge tube containing pyrolysis medium M, adding 10mL of extraction solvent methanol and internal standard deuterated anthracene, and performing collision extraction for 4m·s. -1 Centrifuge (4,000 rpm) for 1 min; then centrifuge for 2 min, and filter the supernatant through a membrane for GC-MS analysis. Intra-day and inter-day precision experiments were conducted on the new treatment method, and the results are shown in Table 7. The intra-day precision RSD was 0.36%–3.94%, and the inter-day precision RSD was 1.55%–5.23%, demonstrating high stability and the ability to detect low levels of photoinitiators that are undetectable by industry-standard methods.

[0083] Table 7.1 Comparison of traditional and new methods and intraday precision experiments of the new method

[0084]

[0085] Table 7.2 Results of daytime precision test of the new method

[0086]

[0087] Note: ND: Below the detection limit, its content cannot be determined.

[0088] Example 8: Detection of actual samples

[0089] An optimized media collision extraction pretreatment method coupled with GC-MS was used to analyze photoinitiators contained in various packaging materials in daily life. Twenty paper packaging samples of food (including milk, biscuits, instant noodles, yogurt, and disposable paper cups) were tested, with each sample tested in triplicate. Eleven positive samples were detected, and the test results are shown in Table 7. Specifically, 1173 was detected in 5 samples, 2-MBP in 2 samples, 4-MBP in 2 samples, 184 in 2 samples, BDK in 1 sample, 907 in 1 sample, PBZ in 2 samples, BP in 3 samples, MBF in 2 samples, and EHDBA in 1 sample. Figure 4 4-MBP (0.973 mg / m³) was detected in the biscuit packaging paper. 2 ) and EHDBA (2.452 mg / m²) 2 The chromatogram of the sample was obtained. Quantitative results showed that this method can rapidly and effectively detect and quantify a variety of photoinitiators. Figure 5 The changes in paper samples before and after processing using the method developed in this invention are shown.

[0090] Table 8. Detection results of photoinitiators in food packaging materials

[0091]

[0092] This invention establishes a rapid pretreatment and detection method for 18 photoinitiators (PIs) in food packaging materials. The method exhibits high recovery rates, and the limits of detection and quantitation are significantly lower than those of industry standard methods. Analysis of actual samples demonstrates that this method is rapid, simple, highly efficient, and accurate, making it suitable for high-throughput processing and detection of 18 photoinitiators in food packaging materials. Furthermore, due to the advantages of this method, the sensitivity for photoinitiator detection is higher, enabling the detection of low concentrations of photoinitiators that are undetectable by traditional methods.

Claims

1. A sample preparation method for determining photoinitiators in packaging materials, characterized in that, The system consisting of the packaging material to be tested and the extractant is extracted in a medium collision extractor, and then the solid-liquid separation is performed to obtain the sample solution to be tested. The extractant is methanol; The ratio of the sample area to the extractant volume, in terms of the solid-liquid ratio, is 1~10 cm². 2 / mL; The linear velocity of the media collision extractor is 4 m / s. -1 ~5.5m·s -1 ; During the extraction process, the pyrolysis medium used is 1 / 4-inch cylindrical ceramic beads; the time of a single extraction process is less than or equal to 60 seconds, and the total time of the extraction process is 1 to 3 minutes. The photoinitiator is at least one of 2-methylbenzophenone, 3-methylbenzophenone, 4-isopropylthioxanthone, and biphenylbenzophenone.

2. The sample preparation method for determining photoinitiators in packaging materials according to claim 1, characterized in that, The media collision extraction instrument is MP Biomedicals' FastPrep. @ -24 instrument.

3. The sample preparation method for determining photoinitiators in packaging materials according to claim 1, characterized in that, The photoinitiator is 3-methylbenzophenone or biphenylbenzophenone.

4. The sample preparation method for determining photoinitiators in packaging materials according to claim 1, characterized in that, The packaging material is food packaging paper.

5. The sample preparation method for determining photoinitiators in packaging materials according to claim 1, characterized in that, Centrifuge the sample solution for 2 minutes, filter it through a membrane, and then perform GC-MS analysis.

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