最新刊期
卷 40 ， 期 11 ， 2021
- 摘要：An ultra-performance liquid chromatography coupled to quadrupole time of flight mass spectrometry（UPLC－QTOF MS） was established and employed for the untargeted screening of non-volatile organic compounds in washed recycled polyethylene terephthalate（rPET） flakes．Influences of pretreatment methods including choice of precipitation solvent，method of solvent removal，amount of test sample，and the chromatographic conditions including different mobile phases and eluent gradients on the determination of non-volatile organic compounds in rPET bottle flakes were investigated．A satisfied results could be obtained by using the following optimized condition or method：0.2 g rPET flakes was dissolved in 10 mL hexafluoro-isopropanol，20 mL methanol was used as precipitation solvent，the solvent was removed by nitrogen-assisted evaporation，methanol－0.1% formic acid water system was used as the mobile phase by gradient elution，and the data-dependent acquisition（DDA） mode was employed as data acquisition method．The qualitative analysis on the analyte was carried out by using MS database and secondary spectroscopy，while the semi-quantitative analysis was performed using compounds with similar structures．A total of 30 non-volatile organic compounds were detected in the rPET flakes，with amount of 0.038－4.92 mg/kg．The detected compounds included 27 types of non-intentionally added substances such as cyclic and linear oligomers，by-products of additives，degradation and contaminants，and the remaining 3 compounds might be associated with intentionally added additives．The recoveries ranged fron 66.0% to 80.4%，with relative standard deviations（RSD） not higher than 5.1%，indicating that this method has good stability and repeatability．24 types of rPET bottle flakes（rPET C and rPET N） from two different geographic manufacturers were detected by the established non-targeted screening methods with principal component analysis（PCA）．The（PCA） results showed that there were significant differences observed between rPET group C and group N，while 15 different types of compounds were detected．These results indicated that the recycled PET bottle flakes with the same type but having different sources may have different compositions．The UPLC－QTOF MS method was demonstrated to be accurate，reliable，simple and rapid，which could be effectively used for the analysis and safety assessment of non-volatile organic compounds in rPET intended for food contact applications.关键词：recycled polyethylene terephthalate（rPET）;ultra-performance liquid chromatography－quadrupole time-of-flight mass spectrometry（UPLC－QTOF MS）;non-intentionally added substances;untargeted screening
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发布时间：2023-02-13 - 摘要：Based on the whole chain of recycled polyethylene terephthalate（recycled PET，rPET），potential migrants in recycled flakes，pellets，preforms and bottles/migrants in the food simulation solution were untargeted screened by ultrahigh performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry（UPLC－Q－TOF MS）．Thirty kinds of intentionally or non-intentionally added substances including PET oligomers，lubricants and rinsing agents were screened out．MS－DIAL（Mass spectrometry－data independent analysis software） was employed to screen the markers of rPET products in different production stages．The results showed that new PET oligomers were formed during the processing from pellet to preform．Alcohol ethoxylate was detected in the flakes of rPET due to the clean process．Comparing the relative content of PET oligomers，it was found that the relative content of cyclic oligomers in rPET was higher than that of linear oligomers，while the relative content of the second series of cyclic dimers was the highest．The relative content of several kinds of oligomers and lubricants increased during rPET processing．Finally，the TEST（Toxicity estimation software tool） was used to predict the rat oral acute toxicity，developmental toxicity and Ames mutagenicity of potential migrants/migrants．And the classification of potential migrants/migrants by Cramer rules was performed by Toxtree software. It was found that PET cyclic oligomers and amide lubricants were all classified as Cramer Ⅲ，which was more toxic than linear oligomers，suggesting that attention should be paid during the rPET recycling process．关键词：recycled PET;food contact materials;ultrahigh performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry;MS－DIAL;risk assessment
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发布时间：2023-02-13 - 摘要：Analysis of polycyclic aromatic hydrocarbons（PAHs） has drawn great attention due to their high bio-accumulative，carcinogenic and teratogenic properties．PAHs might migrate to foods through contaminated food contact materials（FCMs），causing huge potential damages to human health．It is very important to screen PAHs in FCMs with high rapidity and accuracy．Surface-enhanced Raman spectroscopy（SERS） is a promising optical tool for contaminants screening due to its unique properties of rapidity，sensitivity and molecule fingerprint characteristic．However，PAHs is a class of pollutants including over 200 chemicals with two or more benzene rings，meaning the similar structure and overlapping of characteristic Raman peaks．Principal component analysis（PCA） is an ideal data processing method，which could be used to extract useful information from large amount of data by dimensionality reduction process.Researchers have developed methods for identifying chemicals with similar structure by SERS combined with PCA method，obtaining good segregation and identification results．In this paper，a simple analytical method was established for rapid screening of four PAHs，i.e.pyrene（Pyr），fluoranthene（FlA），benzo［b］fluorathene（BbF） and benzo［k］fluorathene（BkF） in FCMs of polyethylene terephthalate（PET） and polypropylene（PP） based on the combination of SERS and PCA．Ag nanoparticles（AgNPs） were mixed with inorganic salt of potassium iodide（KI） to form the aggregated AgNPs with denser“hot spot”，which were used as the enhanced substrate for SERS analysis with high sensitivity．In order to obtain the optimum sensitivity，some analytical parameters including inorganic salt，concentration of KI，incubation time and volume ratio of KI∶BbF∶AgNPs were optimized．Under the optimum conditions，the Raman characteristic peak of Pyr，FlA，BbF and BkF were recorded and sorted for next PCA analysis．Afterwards，PCA method was adopted for the rapid identification of four PAHs to overcome the overlapping of characteristic peaks with similar structure．Results showed that the four PAHs could be easily and obviously identified in the same or different concentration or mixed samples．In addition，the minimum tolerance method was used for identifying PAHs in mixed samples with better segregation and identification results，indicating that the minimum tolerance method could eliminate interference of mixed PAHs samples with similar structure．Furthermore，two FCMs including PET and PP were migrated in 95%（by volume） ethanol at 100 ℃ for 4 h to evaluate the feasibility and accuracy．The migration of PAHs in PET and PP FCMs were rapidly screened and identified based on the established method with satisfactory results，indicating the practicability and accuracy of the PCA－SERS method．The developed method shows great potentials in rapid screening of four PAHs in FCMs migration with high rapidity，accuracy and practicability，which could be used to monitor the safety of FCMs containing PAHs．Also，the method could be used for the detection and screening of other contaminants in FCMs．关键词：surface-enhanced Raman spectroscopy;principal component analysis;food contact materials;polycyclic aromatic hydrocarbons;rapid screening
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发布时间：2023-02-13
Scientific Paper
- 摘要：In order to solve the “odor” problem in food contact paper，ensuring the safety of food contact paper，a static headspace/gas chromatography－mass spectrometry（SHS/GC－MS） combined with spectrum search and retention index was used for the identification of volatile odorous substances in food contact paper，and the semi-quantitation was carried out by means of peak area normalization method. Meanwhile，the main odorants that make up the paper's “peculiar smell” was identified by calculating the relative odor activity value（ROAV）．Under three conditions of equilibrium temperature（80，100 and 120 ℃） and equilibrium time（20，30 and 40 min），120 ℃ and 30 min were optimally selected as static headspace conditions. A total of 119 volatile and semi-volatile organic compounds were detected in all paper samples， 106 of which could be identified by MS－DIAL software．According to the results of the odor library search，there are 51 volatile odor components in these paper samples，including 10 categories such as aldehydes，ketones，alcohols，alkanes，aromatic hydrocarbons，olefins，heterocyclics，esters，ethers and carboxylic acids．Among them，（E，E）-2，4-nonadienal（ROAVmin = 100），nonanal（ROAVmin = 18.16），decanal（ROAVmin = 30.77），（E）-2-nonenal（ROAVmin = 2.05）， 2-pentylfuran（ROAVmin = 1.86）， octadecane（ROAVmin = 1.06） and styrene （ROAVmin = 2.04） have minimum relative odor activity values above the level of key odor components. The results showed that （E，E）-2，4-nonadienal，nonanal，decanal，（E）-2-nonenal，2-pentylfuran，octadecane and styrene are the key odor compounds in food contact paper. Under the test conditions used in this research，the SHS/GC－MS method is convenient and efficient to determine the volatile organic compounds in food contact paper．In the production process of food contact paper，the contribution of key odorants could be reduced through the selection of raw materials and additives，so as to solve the problem of paper “odor”．The research results could provide a technical support for process improvement，volatile odor detection and analysis in the food contact paper industry，and lay a foundation for the optimization of food contact paper production processes in the future.关键词：food contact paper;static headspace/gas chromatography－mass spectrometry;retention index;volatile odorous substances;relative odor activity value;peculiar smell
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发布时间：2023-02-13 - 摘要：A method of Fourier transform infrared spectroscopy（FT－IR） coupled with gas chromatography－mass spectrometry（GC－MS） was applied to the qualitative analysis of key chemical components in unknown coating．The components extraction methods and solvents were optimized，and the optimal pretreatment conditions were determined．The coating was dried into film at a constant temperature，then the coating film was cut into stripes and fragments，respectively．After the pieces were extracted with acetonitrile and methanol successively，they were centrifuged at a high speed，and dissolved in tetrahydrofuran．In addition，the stripes and the insoluble matters were analyzed by FT－IR after dissolving．Furthermore，combined with absorption peaks and spectral libraries as well as software，all unknown components were determined．According to the results obtained，the coating film-forming substance was judged to be acrylate to a great extent．Meanwhile，coatings，acetonitrile extracts and methanol extracts were analyzed by GC－MS．Retention index，spectral libraries and literatures were used for the qualitative analysis．Results showed that the solvents in the coating mainly consisted of 2-ethylhexanol，o-xylene，m-xylene，acetophenone，giving coating special odors．What’s more，additives possibly included 1-methylnaphthalene，methyl palmitate，α-methyl styrene，2，4-di-tert-butylphenol，2，4-dimethyl-6-tert-butylphenol and oleamide，etc．The polymerization monomers in the unknown coating were butyl methacrylate and isooctyl acrylate．关键词：coating;component analysis;Fourier transform infrared spectroscopy（FT－IR）;gas chromatography－mass spectrometry（GC－MS）;acrylate
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发布时间：2023-02-13 - 摘要：To address the current issues of traditional methods for photoinitiators（PIs） quantitation，which are time-consuming and have no spatial resolution，a quantitative mass spectrometry imaging method was developed，based on a liquid microjunction surface sampling（LMJSS） technique which is a simple，flexible and low-cost ambient sampling method for mass spectrometry. In this technique，solid surface could be sampled in situ with liquid solvent in a confined area prior to ionization in MS，which makes it possible to achieve in situ analysis or mass spectrometry imaging．Also，it is flexible to tune the sampling selectivity by solvent compositions or add standard in sampling solvent for quantitation in LMJSS technique．In the previous study，the problem of in situ quantification on PIs in packaging paper was effectively solved by combing LMJSS technique with kinetic calibration method．In this study，LMJSS technique was applied to the mass spectrometry imaging of PIs．Results showed that higher sensitivities were obtained for PIs by directly connecting the flow probe of LMJSS system to the inlet of mass spectrometry．Using this imaging method，the kinetic curve（signal-time curve） of analytes could be obtained in each pixel．According to the kinetic curves，it was proved that the extraction efficiencies of PIs in single pixel after 1 min LMJSS were all above 90%，making the quantitation by external standard calibration possible．This new method was finally applied to the quantitative mass spectrometry imaging for PIs in packaging material. The absolute concentrations of PIs in each pixel could be obtained by scanning the sample surfaces with the LMJSS technique，and the quantitative results were compared with those by traditional PIs quantitation method using gas chromatography－mass spectrometry．From the results，it is found that more kinds of PIs could be detected by the new mass spectrometry imaging method than traditional method，and the quantitation results by two methods were mostly comparable．Moreover，the imaging method could provide the spatio－chemical information which could not be obtained by traditional method. For example，in a certain area of paper packaging material，more isopropylthioxanthone（ITX），4-benzoylbiphenyl（PBZ），2-ethylhexyl-4-dimethylamino benzoate（EHDBA） and o-methyl-benzoyl benzoate（OMBB） were found to distribute in regions of red inks，while benzophenone（BP） and 1-hydroxycyclohexyl phenyl ketone（PI184） mainly distributed in regions of green inks．This specific spatial distribution of PIs makes them difficult to be detected by the traditional quantitative method．The developed imaging method is of great significance for screening and localizing PIs in packaging materials，and for guiding and improving the coating formulation or process of UV curable ink．It can also provide a technical support for the quality control of PIs in packaging materials．关键词：liquid microjunction surface sampling;mass spectrometry imaging;photoinitiators;quantitation analysis;packaging materials
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发布时间：2023-02-13 - 摘要：Polyethylene terephthalate（PET） is an excellent material for recycling due to its low diffusivity and low sorption features．The ideal recycling is to use the recycled PET（rPET） material for the initial intended use．There are some intentionally added and non-intentionally added risk substances in rPET．There will be some safety risks if these substances migrate into food．Due to insufficient data on rPET pollutants for safety assessment，rPET cannot be used in food contact materials in China．In this study，a method was established for the analysis of volatile organic compounds（VOCs） in rPET using comprehensive two-dimensional gas chromatography－quadrupole time-of-flight mass spectrometry（GC × GC－QTOF MS） combined with headspace solid phase microextraction（HS-SPME）．Influences of different SPME fibers（PDMS，DVB/PDMS and DVB/C-WR/PDMS），extraction temperatures（50，70，90，110，130，150 ℃），headspace equilibrium times（15，30，60 min），modulation periods（2，4，6 s） and heating rates of oven（3，5，8，10 ℃/min） on the determination effect were compared．The VOCs were identified with NIST library combined with Kovats indexes．The content of high-frequency compounds was determined by semi-quantification．The best HS-SPME and instrument conditions were as follows：SPME fiber：80 μm DVB/C-WR/PDMS，extraction temperature：110 ℃，equilibrium time：30 min，modulation period：4 s，and heating rate of oven：8 ℃/min. 209 volatile organic compounds were determined in 9 rPET samples，including aromatic compounds，alkanes，alcohols，aldehydes，ketones，esters，olefins，naphthalene，carboxylic acids and phenols．Aromatic compounds could be derived from the degradation of rPET in different environments．Terpene may come from the residue of flavor substances in early PET bottle drinks．Among the 9 rPET samples，the substances with detection frequency greater than 5 were d-limonene，γ-terpinene，5-methyl-1-undecene，tetradecane，naphthalene，1-methyl-naphthalene，1-ethylidene-1h-indene，2-dodecanol，2-decanone and 2，4-di-tert-butylphenol．D-Limonene is a common pollutant in rPET，which comes from the contact between original PET bottle and beverage．2，4-di-tert-butylphenol may be the degradation product of antioxidant 168，and remaining in rPET．The highest content of high-frequency compounds was 2.13 mg/kg（tetradecane）．No misused compound with extremely high concentration was found．This research provided not only a scientific and reliable methodological basis for the investigation of VOCs in rPET，but also the basic data for utilization and safety assessment of rPET.关键词：recycled polyethylene terephthalate（rPET）;comprehensive two-dimensional gas chromatography－quadrupole time of flight mass spectrometry;volatile organic compounds;method optimization
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发布时间：2023-02-13 -
Determination and Influencing Factors of Migration of Primary Aromatic Amines in PA/CPP Retort Pouch
摘要：A liquid chromatography－triple quadrupole tandem mass spectrometry（LC－MS/MS） was developed for determination of the migration amounts of three primary aromatic amines（PAAs） including 2，4-diaminotoluene，2，6-diaminotoluene，4，4′-diaminodipheny/methane in Polyamide/cast polypropylene（PA/CPP） retort pouch．Results showed that this method has the advantages of simple operation and high sensitivity，which meets the specific migration limit（SML） detection requirements for individual PAAs revised in the European Regulation（EU） No 10/2011. This method was used to detect the migration amounts of PAAs in 30 kinds of PA/CPP retort pouches under the condition of 100 ℃ for 2 h．It was found that 4，4´-MDA was detected in all retort pouches，and the migration amounts of 4，4´-MDA in 17 kinds of retort pouches were higher than its SML（0.002 mg/kg）．Afterwards，the influence of heat treatment on retort pouches and the influences of storage and transportation on the migration of 4，4´-MDA in retort pouches were investigated．The results showed that heating temperature and heating time might lead to the increase of isocyanate monomer in retort pouches，and finally promote the migration of PAAs．During the simulation of the storage and transportation process，it is found that the increase in ambient temperature and the vibration during transportation could promote the migration of 4，4´-MDA in retort pouches. The amount of 4，4´-MDA migration might exceed the standard if the sample bag was exposed to an ambient temperature of 60 ℃ for 5 d，and there may be food safety issues.关键词：polyamide/cast polypropylene（PA/CPP）;primary aromatic amines（PAAs）;liquid chromatography-tandem mass spectrometry（LC－MS/MS）;food simulants;migration- 2
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发布时间：2023-02-13 - 摘要：In order to investigate the volatile odor components of recycled polyethylene（PE） and their contribution to the overall odor of recycled PE，the volatile odor compounds in 8 kinds of recycled PE were analyzed by headspace solid phase microextraction/gas chromatography－mass spectrometry（HS－SPME/GC－MS） coupled with retention indexs（RI）．The main odor substances were evaluated by relative odor activity value（ROAV）．The extraction temperature was 80 ℃，the equilibrium time was 30 min，the extraction time was 40 min，the extraction fiber was 50/30 μm DVB/CAR/PDMS and the chromatographic column was HP－5 MS（30 m × 0.25 mm，0.25 μm）．Results showed that 47 odor substances in 8 kinds of recycled PE were detected，including 14 esters，11 alcohols，6 ketones，4 aldehydes，4 phenols，2 alkanes，2 olefins，2 ethers，1 carboxylic acid and 1 amine．Among the obtained odor compounds，there were 31 kinds of common ingredients. The ROAV showed that nonanal，isophorone，amyl salicylate，diphenyl ether，2-methoxynaphthalene，phenol and borneol were the main odor substances in eight kinds of recycled PE. The odor of recycled PE was one of the important factors limiting its application．This research could provide a theoretical basis for the improvement of degassing and deodorization process of recycled PE．关键词：recycled polyethylene;headspace solid phase microextraction/gas chromatography－mass spectrometry;main odor substances;relative odor activity value
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发布时间：2023-02-13 - 摘要：A high performance liquid chromatographic（HPLC） method was established for the simultaneous determination of 9 phenols such as phenol，methyl-phenols and xylenols in food simulants. The sample was separated on an Agilent ZORBAX SB－Aq column by gradient elution，using methanol and water as mobile phase at a flow rate of 1.0 mL/min，and finally determined by fluorescence detection at an excitation wavelength of 214 nm and an emission wavelength of 315 nm．Meanwhile，the extraction method for 9 phenols in the fat-contained simulant was optimized，and the performances of the method including linearity，spiked recovery and precision were studied．Results demonstrated that 67% methanol aqueous solution was the best extraction solvent for the 9 phenols in fat simulants．The results also showed that there were good linear relationships for 9 phenols in all food simulants studied，with correlation coefficients（r2） higher than 0.999．The recoveries for 9 phenols at 3 spiked levels in all food simulants ranged from 90.7% to 99.8%，with relative standard deviations （RSD） all below 6.0%．The limits of quantitation（LOQs） were in the ranges of 0.07－0.10 mg/L for aqueous simulants，and 0.15－0.20 mg/kg for fat simulants. This method was successfully applied to the migration determination of 9 phenols released from 11 plastics articles（PC） and 15 coatings intended to contact with food．The method was sensitive and accurate，and was suitable for the determination of 9 phenols in food simulants.关键词：phenols;migration;food contact materials;high performance liquid chromatography （HPLC）;fluorescence detector
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发布时间：2023-02-13
Scientific Papers
- 摘要：In this study，different polylactic acid（PLA） straw samples were collected，and migration experiments were carried out to simulate the usage of PLA straws in real cases. Then，an ultrahigh performance liquid chromatography－quadrupole time-of-flight mass spectrometry（UHPLC－QTOF MS） method was developed for analysis of the chemicals migrated from PLA straws into food simulants．Identification of the migrants was performed via both targeted and non-targeted screening procedures．A total of 30 migrants were identified in different straw samples and food simulants. These identified migrants could be divided into two categories，i.e. oligomers and additives．Considered as non-intentionally added substances（NIAS），the oligomers mainly included polybutylene succinate（PBA） and butylene glycol-hexane diacid-terephthalate acid copolymer（PBAT） in cyclic form．The additives included antioxidants，lubricants and plasticizers， as well as the NIAS related to them such as raw materials，impurities，byproducts，etc．Among all migrants，only 5 of them were found in the positive list of GB9685－2016．Hazard assessment on the rest migrants were performed using threshold of toxicological concern（TTC） approach combined with Cramer decision tree．Most of them were assigned Cramer class Ⅲ（high toxicity），which required special attention to ensure the safe use of PLA straws.关键词：PLA straws;ultrahigh performance liquid chromatography－quadrupole time-of-flight mass spectrometry（UHPLC－QTOF MS）;migrant identification;hazard assessment
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发布时间：2023-02-13 - 摘要：An ultra-high performance liquid chromatography－tandem mass spectrometry was established for simultaneous determination of the migration of 20 photo initiators in food contact inks in order to assess the migration risk of photo initiators in food contact inks．The sample was separated using a mixture of 0.1%（volume fraction） formic acid and methanol solution as the mobile phase by gradient elution. 20 kinds of photo initiators in the food simulants were detected after the migration experiment，and the quantitative and qualitative ions of the target were monitored in multi-reaction monitoring mode．Results showed that the chromatographic separation effects of this method for the photo initiators were good，and there existed good linear relationships for each substance in the concentration range of 0.02－0.5 mg/L，with their detection limits and quantitation limits of 0.01 mg/kg and 0.02 mg/kg，respectively．The spiked recoveries ranged from 87.1% to 104%，with relative standard deviations（RSD） of 2.1%－8.6%．A total of 4 types of photo initiators were detected in 10 samples．This method is simple，sensitive and accurate，and is suitable for the detection of the migration amount of 20 photo initiators in food contact inks.关键词：photo initiator;migration;food contact material;ultra-high performance liquid chromatography－tandem mass spectrometry
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发布时间：2023-02-13 - 摘要：While biodegradable plastics continually exhibit many excellent properties，their safety has been increasingly concerned．In this study，the migration risk of calcium in food contact degradation composite film was evaluated，with polylactic acid（PLA） and polylactic acid/poly（butyleneadipate-co-terephthalate） （PBAT） as the substrates and calcium carbonate （CaCO3） as the inorganic filler．The calcium concentrations in five kinds of PLA/PBAT/CaCO3 composite films with various contents of CaCO3 were determined by inductively coupled plasma optical emission spectrometry（ICP－OES）．Meanwhile， the PLA/PBAT/CaCO3 films were characterized by scanning electron microscopy（SEM）．The overall migration of PLA/PBAT/CaCO3 films into three food simulants（3% acetic acid，10% ethanol，95% ethanol） were investigated，and the relationship between the overall migration results and the calcium content was explored．Migrations of calcium from PLA/PBAT/CaCO3 films into the acidic food stimulant of 3% acetic acid at 40 ℃/24 h and 70 ℃/2 h were investigated，respectively．Furthermore，effect of ultraviolet aging treatment on the migration was also studied．Results showed that the overall migration of the five composite films into 95% ethanol was higher than that into 10% ethanol，and the overall migration into 3% acetic acid exceeded the overall migration limit（OML），which may lead to food safety risks．The overall migration was mainly affected by CaCO3，and the calcium concentration had a linear relationship with the overall migration into 3% acetic acid．With the increase of CaCO3 content，different degrees of agglomeration occurred on the surface of the films，while the migration of calcium was affected by the agglomeration．For all the composite films with different CaCO3 contents，the migration equilibriums were obtained in a short time（40 ℃，4 h）．The long time（more than 24 h） UV aging for composite film inhibited the calcium migration due to the cross-linking of PBAT．The safety of these biodegradable composite films as food contact materials is worth further study．关键词：food contact material;bio-degradation film;polylactic acid（PLA）;calcium carbonate;migration;ultraviolet aging
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发布时间：2023-02-13 - 摘要：An ultra performance liquid chromatography－tandem mass spectrometry was established for the determination of acrylamide in order to evaluate and study the compliance and risk of acrylamide migration in paper-based food contact materials．In this method，the test solution was separated on an Agilent Poroshell 120 SB－Aq column（4.6 mm × 100 mm，2.7 μm） with 0.1% formic acid（volume fraction） and methanol solution（9∶1） as mobile phases．The MS detection was performed in positive electrospray ionization（ESI） under multiple reaction monitoring（MRM） mode．The method validation results indicated that there were good linear relationships for acrylamide between the content and chromatographic peak areas in different food simulants．The linear relationships were obtained in the range of 5.0－100.0 μg/L for water-soluble food simulants and 10.0－200.0 μg/kg for oily food simulant，with their limits of detection（LOD） of 1.0 μg/L and 5.0 μg/kg，respectively．The spiked recoveries varied from 90.0% to 113%，with relative standard deviations（RSD，n = 6） of 0.40%－4.6%．The established method was applied to the determination of three kinds of paper-based food contact materials．Results showed that paper straw has higher acrylamide migration and more potential food safety risk than the other two materials.关键词：ultra performance liquid chromatography－tandem mass spectrometry;food contact materials;acrylamide;migration
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发布时间：2023-02-13 - 摘要：Trimethylolpropane，tetrahydrofurfuryl alcohol and 1，6-hexanediol are the raw materials or additives used in the production of laminated films and pouches for food packaging．These three substances may remain in products and migrate into food，thus affecting human health．Specific migration limits（SML） for the above three substances are clearly stipulated in the relevant standards of China．Therefore，it is extremely necessary to establish a targeted detection method for the migration of the above three alcohols in laminated films and pouches for food packaging．A liquid chromatography－tandem mass spectrometry（LC－MS/MS） was established for the simultaneous determination of trimethylolpropane，tetrahydrofurfuryl alcohol and 1，6-hexanediol in laminated films and pouches for food packaging in this paper. Laminated films and pouches were treated with different simulants according to related regulations and standards. After soaking in food simulants， the simulated samples were pretreated with appropriate manners．Water-based，acid-based and part of alcohol-based（ethanol contents are equal to or less than 10% by volume） simulated samples were directly filtered．Other alcohol-based（ethanol contents are more than 10% by volume） simulated samples were adjusted to their original volume with water after removing most of alcohol by nitrogen blowing．The olive oil simulated sample was detected after extraction with 10% methanol solution．The separation was performed on an C18 column by gradient elution with formic acid（0.01%） and acetonitrile as mobile phases．The detection was performed with electrospray ion source in positive ion（ESI+） under multi reaction monitoring（MRM） mode．Meanwhile，external standard method was used for quantitative determination．Results indicated that this method exhibited perfect linear relationships for the 3 alcohols，with their correlation coefficients（r） more than 0.999．The recoveries at three spiked levels ranged from 88.9% to 116%，with relative standard deviations（RSD） of 0.70%－5.0%．The limits of detection（LODs，S/N ≥ 3） and limits of quantitation（LOQs，S/N ≥ 10） for trimethylolpropane in olive oil were 20 µg/kg and 40 µg/kg，respectively，and the LODs and LOQs for both tetrahydrofurfuryl alcohol and 1，6-hexanediol in olive oil were 4 µg/kg and 10 µg/kg，respectively．Meanwhile，the LODs and LOQs for the 3 alcohols in other food simulants were 4 µg/L and 10 µg/L，respectively．The method is simple，reliable，sensitive and stable．The food simulants included in the method basically covered the types specified in the regulations and standards．The LODs and LOQs of the method were lower than the specific migration limits（SML） specified in the regulations and standards．The method could meet the needs for migration determination of 3 alcohols in laminated films and pouches for food packaging.关键词：liquid chromatography－tandem mass spectrometry（LC－MS/MS）;laminated films and pouches for food packaging;trimethylolpropane;tetrahydrofurfuryl alcohol;1，6-hexanediol;migration
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发布时间：2023-02-13 - 摘要：A gas chromatography－mass spectrometry（GC－MS） was developed for the determination of migration of 2-methyl-1，3-propanediol（MPO） and 2，2-methyl-1，3-propanediol（NPG）in food contact materials. After the migration test of food contact materials，the obtained soaking solution was firstly derivatized with phenylboric acid solution，then extracted with n-hexane，and finally determined by GC－MS. Results showed that there were good linear relationship of this method in the optimized conditions，with correlation coefficients（r2） larger than 0.995. The detection limits for MPO and NPG in 4% acetic acid，10% ethanol，50% ethanol and isooctane were all 0.01 mg/L within linear ranges of 0.02－0.10 mg/L.The detection limit of MPO in 95% ethanol was 0.30 mg/L within a linear range of 0.50－1.6 mg/L. The detection limit for NPG in 95% ethanol was 0.03 mg/L within a linear range of 0.05－0.16 mg/L.The relative standard deviations（RSD） of this method were in the range of 0.60%－9.5%，and the average recoveries were 85.0%－112%.With the high accuracy and sensitivity，the method could be used to determine the migration of 2-methyl-1，3-propanediol and 2，2-methyl-1，3-propanediol in food contact coatings and plastic products， so as to meet the limited requirements of Chinese regulations.关键词：2-methyl-1，3-propanediol（MPO）;2，2-methyl-1，3-propanediol（NPG）;food contact materials;gas chromatography－mass spectrometry （GC－MS）;derivatization method
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发布时间：2023-02-13
Experimental Techniques and Methods
- 摘要：Plastic food contact materials are the most commonly used category of materials．The chemical hazardous substances potentially contained in plastic food contact materials may contaminate food and threaten food safety by absorption，dissolution，diffusion，and other migration behaviors．It has always been a great challenge for the analysis of plastic food contact materials to identify and quantify the migrants in plastic food contact materials with appropriate sample pretreatment and analytical techniques．In this paper，the sample pretreatment and instrumental analytical techniques for plastic food contact materials are reviewed．The development trend and application prospect are discussed，which may provide some technical instructions for the researchers engaged in the quality and safety control of plastic food contact materials.关键词：plastic food contact materials;sample pretreatment;analytical techniques;review
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发布时间：2023-02-13 - 摘要：In this paper，the sources，extraction and analysis methods of microplastics in food were systematically reviewed，and the related countermeasures were proposed for the research of microplastics to promote the treatment of microplastics in food．Research has shown that food raw materials，processing and packaging are all potential sources of microplastics，while digestion is the primary method to extract microplastics in food．At present，the main methods for the identification and quantification of microplastics in food include visual method，Fourier transform infrared spectroscopy，Raman spectroscopy，scanning electron microscopy，pyrolysis/gas chromatography－mass spectrometry，etc．In the future，it is suggested that study on standard test method for microplastics in food should be carried out，and the spectral identification and quantitative techniques for nanoscale microplastics should be developed. Meanwhile，confronting more and more serious microplastics pollution in food，the traceability analysis and control technology research of microplastics pollution in the process of food production should be strengthened，and the development of new materials should be speeded up.关键词：microplastics;food safety;Fourier transform－infrared spectroscopy;Raman spectroscopy;scanning electron microscopy;pyrolysis/gas chromatography－mass spectrometry
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发布时间：2023-02-13
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