Method for determining migration volume of 3-butene-2-alcohol in food contact material and product by using dry food simulant

Abstract

The invention discloses a method for determining the migration volume of 3-butene-2-alcohol in a food contact material and a product by using a dry food simulant. The method comprises the following steps: S1, dissolving 3-butene-2-alcohol in a solvent, and preparing a standard working solution of 3-butene-2-alcohol; s2, the pretreated simulation material is transferred into a headspace bottle, a solvent is added to prepare a sample solution, and the simulation material is prepared from a food contact material and dry food simulant modified polyphenyl ether through a migration experiment; s3, dissolving the dry food simulant modified polyphenyl ether in a solvent to prepare a blank sample solution; and S4, detecting the standard working solution, the sample solution and the blank sample solution by using headspace-gas chromatography / mass spectrometry, and performing quantitative analysis by using a peak area. The invention relates to a method for determining the migration volume of 3-butene-2-alcohol in modified polyphenyl ether by adopting a headspace-gas chromatography / mass spectrometry method. The method is high in sensitivity and low in detection limit.

Description

Technical Field:

[0001] The present invention relates to the technical field of analysis of food contact materials, and particularly to a method for determining the migration amount of 3-buten-2-ol in food contact materials and articles by using a dry food simulant. Background Art:

[0002] At present, there is no report on the detection technology for the migration amount of 3-buten-2-ol in modified polyphenylene ether (MPPO) at home and abroad. 3-Buten-2-ol (also known as methyl vinyl carbinol), with an appearance of colorless transparent liquid, is a widely used organic chemical raw material. As an important intermediate for synthesizing monomer esters and drugs, it is applied in many fields such as plastics, rubber, coatings, daily chemical industry, pharmaceutical manufacturing, dyes, etc. 3-Buten-2-ol can be used as an additive in food-contact coating products. If the production process is not qualified, it may lead to residues in the products and migrate into food through contact with food, thus posing a threat to human health. 3-Buten-2-ol is a highly toxic substance, and the median lethal dose (LD 50 ) for rats by oral administration is 34 mg / kg. The specific migration limit (SML) of 3-buten-2-ol is specified as not detectable (the detection limit is 0.01 mg / kg) in China's standard GB9685-2016.

[0003] The detection method for the migration amount of 3-buten-2-ol in modified polyphenylene ether (MPPO) has obvious lag. For small molecule alcohol substances similar to the target substance, the currently reported detection methods mainly include gas chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, etc. Among them, gas chromatography-mass spectrometry has certain advantages in the qualitative and quantitative analysis of trace low-boiling compounds and is commonly used in the qualitative confirmation and quantitative analysis of such substances. The existing reports mainly focus on the determination of the migration amount of 3-buten-2-ol in water-based simulant, oil-containing food simulant, and chemical alternative solvents. There is no report on the analysis and detection method or related standard of this substance in dry food simulant (modified polyphenylene ether) for the time being, so it cannot meet the increasingly strict regulatory or hygiene standard requirements. Summary of the Invention:

[0004] The present invention solves the problem of the lack of detection method for 3-buten-2-ol in dry food simulant, and provides a method for determining the migration amount of 3-buten-2-ol in food contact materials and articles by using a dry food simulant. This method has little interference and high sensitivity, can meet the detection requirements for the migration amount of 3-buten-2-ol in dry food simulant in food contact materials and articles, and provides a basis for the safety assessment of the use of this target substance in packaging materials.

[0005] The object of the present invention is to provide a method for determining the migration amount of 3-buten-2-ol in food contact materials and articles by using a dry food simulant, comprising the following steps:

[0006] S1. Dissolve 3-buten-2-ol in a solvent to prepare a standard working solution of 3-buten-2-ol with a concentration of 0.02 - 0.20 mg / L, and the solvent is selected from one of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide;

[0007] S2. Transfer the pretreated simulant material into a headspace vial, add a solvent to prepare a sample solution, and the simulant material is prepared by a migration experiment with a food contact material and a dry food simulant modified polyphenylene ether, and the solvent is the same as that in step S1;

[0008] S3. Dissolve the dry food simulant modified polyphenylene ether in a solvent to prepare a blank sample solution, and the solvent is the same as that in step S1;

[0009] S4. Detect the standard working solution, the sample solution, and the blank sample solution by headspace-gas chromatography / mass spectrometry, and perform quantitative analysis on them using the peak area.

[0010] The solvents used in preparing the standard working solution, the sample solution, and the blank sample solution are the same.

[0011] The technical route adopted by the method proposed by the present invention is as follows: using modified polyphenylene ether (MPPO) as a food simulant for a migration experiment, after the target substance migrated out from the food contact materials and articles is adsorbed by MPPO, adding a high-boiling solvent as a diluent, and performing analysis by headspace-gas mass spectrometry, and quantifying by external standard method of peak area.

[0012] The present invention selects modified polyphenylene ether (MPPO) as a dry food simulant for a migration experiment; adding a high-boiling solvent as a diluent to remove the matrix effect, saving the use of the dry simulant in the standard curve, and saving costs; a method for determining the migration amount of 3-buten-2-ol in modified polyphenylene ether by headspace-gas chromatography / mass spectrometry (HS-GC / MS); the method has high sensitivity and low detection limit.

[0013] Preferably, the standard working solution in step S1 is specifically prepared by the following steps:

[0014] S11. Weigh a 3-buten-2-ol standard product and prepare a standard stock solution of 3-buten-2-ol with a concentration of 1000 mg / L;

[0015] S12. Pipette the 3-buten-2-ol standard stock solution into a volumetric flask, and make up to the mark with the solvent to prepare a standard intermediate solution of 3-buten-2-ol with a concentration of 10 mg / L;

[0016] S13. Then, the standard intermediate solution is serially diluted with the solvent described above to prepare standard working solutions of 3-buten-2-ol with concentrations of 0.02 - 0.20 mg / L. The concentrations of the standard working solutions are 0.020 mg / L, 0.040 mg / L, 0.080 mg / L, 0.10 mg / L, and 0.20 mg / L, respectively.

[0017] Preferably, the migration experiment in step S2 is specifically as follows: The modified polyphenylene ether is covered on the surface of the food contact materials and articles in an amount of 3.5 - 4.5 g / dm 2 . After sealing, it is placed in an environment of 40°C - 60°C for 10 days to complete the migration experiment.

[0018] More preferably, the migration experiment in step S2 is specifically as follows: The modified polyphenylene ether is covered on the surface of the food contact materials and articles in an amount of 4 g / dm 2 . After sealing, it is placed in an environment of 60°C for 10 days to complete the migration experiment.

[0019] For bag-like specimens, place the specimens on a glass plate, cover them with the outer cover of a petri dish, and cut along the edge of the outer cover with a paper cutter. At the same time, prepare 3 specimens, lay them flat inside the inner covers of 3 petri dishes respectively, and calculate the specimen surface area based on the area of the inner cover. Cover the surface of the specimens evenly with MPPO in an amount of 4 g / dm 2 , and cover them completely with the inner cover without spilling outside; for container-like specimens, measure the bottom diameter of the container, calculate the bottom area, and cover the bottom of the container evenly with MPPO in an amount of 4 g / dm 2 . If the specimen is irregular and has no flat surface, it is necessary to find a suitable method to make the specimen fully contact with MPPO, cut the specimen into appropriate parts, and then cover it with MPPO. If necessary, the mass of MPPO can be appropriately increased to ensure that the sample is completely covered. Place the above samples to be tested steadily into an oven that has reached the test temperature for the migration experiment. After the migration experiment is completed, take out the samples and place them in a desiccator. After cooling to room temperature, transfer the MPPO covering the surface of the specimens to a 20 mL headspace vial, add a high-boiling solvent, quickly seal the vial, and send it to the instrument for detection.

[0020] Preferably, the working parameters of the headspace-gas chromatography / mass spectrometry method in step S4 are as follows:

[0021] a) Headspace temperature: 85°C - 95°C;

[0022] b) Headspace time: 25 - 35 min;

[0023] c) Chromatographic column: 6% cyanopropyl / phenyl 94% dimethyl polysiloxane capillary chromatographic column, 30 m × 0.25 mm × 1.4 μm, or an equivalent chromatographic column;

[0024] d) The temperature increase program is as follows: maintain at 50 °C for 0 min, increase to 100 °C at a rate of 3 °C / min, and maintain for 2 min; then increase to 250 °C at a rate of 25 °C / min and maintain for 1 min;

[0025] e) Injector temperature: 100 °C - 250 °C;

[0026] f) Column flow rate: 0.5 - 1.5 mL / min;

[0027] g) Injection volume: 1 mL;

[0028] h) Injection mode: split injection, split ratio is 2:1;

[0029] i) Ion source: electron impact ionization source EI;

[0030] j) Ion source temperature: 230 °C;

[0031] k) Quadrupole mass analyzer temperature: 150 °C;

[0032] l) Transfer line temperature: 280 °C;

[0033] m) Ionization energy: 70 eV;

[0034] n) Solvent delay: 5.0 min;

[0035] o) Detection mode: SIM selected ion monitoring mode.

[0036] Further preferably, the operating parameters of the headspace-gas chromatography / mass spectrometry in step S4 are as follows:

[0037] a) Headspace temperature: 90 °C;

[0038] b) Headspace time: 30 min;

[0039] c) Chromatographic column: 6% cyanopropyl / phenyl 94% dimethyl polysiloxane capillary chromatographic column, 30 m × 0.25 mm × 1.4 μm, or equivalent chromatographic column;

[0040] d) The temperature increase program is as follows: maintain at 50 °C for 0 min, increase to 100 °C at a rate of 3 °C / min, and maintain for 2 min; then increase to 250 °C at a rate of 25 °C / min and maintain for 1 min;

[0041] e) Injector temperature: 150 °C;

[0042] f) Column flow rate: 1.0 mL / min;

[0043] g) Injection volume: 1 mL;

[0044] h) Injection mode: split injection, split ratio is 2:1;

[0045] i) Ion source: Electron impact ionization source EI;

[0046] j) Ion source temperature: 230 °C;

[0047] k) Quadrupole mass analyzer temperature: 150 °C;

[0048] l) Transfer line temperature: 280 °C;

[0049] m) Ionization energy: 70 eV;

[0050] n) Solvent delay: 5.0 min;

[0051] o) Detection mode: SIM Selected ion monitoring mode.

[0052] Further preferably, in step S4, the quantitative ion of 3-buten-2-ol is m / z 57, and the qualitative ions are m / z 43, m / z 45, and m / z 71.

[0053] Preferably, the specific steps for quantitative analysis of it using the peak area in step S4 are as follows: Detect the standard working solution by headspace-gas chromatography / mass spectrometry, draw a standard working curve, then detect the sample solution and the blank sample solution by headspace-gas chromatography / mass spectrometry, obtain the peak area of the chromatographic peak of the target to be measured, and calculate the concentrations of 3-buten-2-ol in the sample solution and the blank sample solution according to the standard working curve, so as to obtain the migration amount of 3-buten-2-ol in the food contact material.

[0054] Further preferably, the standard working curve is drawn with the concentration of 3-buten-2-ol in the simulated material as the abscissa, with the unit expressed in mg / kg, and the corresponding average peak area as the ordinate.

[0055] The present invention also protects the application of the above method in determining the migration amount of 3-buten-2-ol in food contact materials and articles.

[0056] Compared with the prior art, the present invention has the following advantages:

[0057] 1. The method proposed by the present invention is based on HS-GC / MS technology to study the migration amount of 3-buten-2-ol in modified polyphenylene ether (MPPO), and establish an accurate and efficient qualitative and quantitative detection technology to achieve the rapid identification and accurate determination of this substance.

[0058] 2. Currently, there is no report on the detection technology for the migration amount of 3-buten-2-ol in modified polyphenylene ether (MPPO) at home and abroad. The method proposed in this invention fills the blank in the determination of the migration amount of target substances in dry food simulants for food contact materials and articles. The headspace gas chromatography-mass spectrometry method for detecting 3-buten-2-ol in modified polyphenylene ether has advantages such as good separation effect, high sensitivity, low detection limit, etc., and also has advantages such as rapidity and solvent saving, and has a very broad application prospect. Adding a high-boiling solvent as a diluent can remove the matrix effect and at the same time reduce the use of dry simulants in the standard curve, saving costs. Description of the Drawings:

[0059] Figure 1 It is the total ion current chromatogram of 3-buten-2-ol in the dry food simulant in Example 1.

[0060] Figure 2 It is the response situation of 3-buten-2-ol on the instrument at different headspace temperatures and times in Example 1 and Example 3.

[0061] Figure 3 It is the response situation of 3-buten-2-ol on the instrument at different headspace temperatures and times in Example 1 and Example 4.

[0062] Figure 4 It is the response situation of 3-buten-2-ol on the instrument at different injection port temperatures in Example 1 and Example 5. Detailed Embodiments:

[0063] The following examples are further illustrations of the present invention rather than limitations thereof.

[0064] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention. Unless otherwise specified, the experimental materials and reagents in this article are all conventional commercially available products in this technical field.

[0065] The reagents used in the following examples: methanol, chromatographically pure; N,N-dimethylacetamide, analytically pure. Standard: 3-buten-2-ol, purity ≥ 98%, or a reference material certified by the state and granted a certificate of reference material.

[0066] The migration experiment steps for food contact materials and articles are as follows: For bag-like specimens, place the specimen on a glass plate, cover it with the outer cover of a petri dish, and cut along the edge of the outer cover with a paper cutter. At the same time, prepare 3 specimens and lay them flat inside the inner covers of 3 petri dishes respectively, and calculate the specimen surface area based on the area of the inner cover. Place the MPPO at 3.5 - 4.5 g / dm 2Cover the surface of the specimen evenly with the specified amount, and completely cover it with the inner lid without spilling outside; for specimen in containers, measure the diameter of the bottom of the container, calculate the bottom area, and cover the bottom of the container evenly with MPPO at a rate of 3.5 - 4.5 g / dm 2 of the specified amount; if the specimen is irregular and has no flat surface, a suitable method needs to be found to ensure full contact between the specimen and MPPO. Divide the specimen into appropriate parts and then cover it with MPPO. If necessary, the mass of MPPO can be appropriately increased to ensure complete coverage of the sample. After sealing, place it in an environment at 40°C - 60°C for 10 days to complete the migration experiment.

[0067] Preferably in the following examples, cover the surface of the specimen evenly with MPPO at a rate of 4 g / dm 2 of the specified amount, and completely cover it with the inner lid without spilling outside; for specimen in containers, measure the diameter of the bottom of the container, calculate the bottom area, and cover the bottom of the container evenly with MPPO at a rate of 4 g / dm 2 of the specified amount; if the specimen is irregular and has no flat surface, a suitable method needs to be found to ensure full contact between the specimen and MPPO. Divide the specimen into appropriate parts and then cover it with MPPO. If necessary, the mass of MPPO can be appropriately increased to ensure complete coverage of the sample. After sealing, place it in an environment at 60°C for 10 days to complete the migration experiment.

[0068] Pretreatment steps for the following specimens: The specimens should be kept clean and avoid direct hand contact. Before preparing the specimens, gently wipe them with non-woven fabric to remove the impurities adhering to the surface of the specimens, and do not wash the specimens with water or solvents.

[0069] Example 1:

[0070] A method for determining the migration amount of 3-buten-2-ol in food contact materials and articles using a dry food simulant, comprising the following steps:

[0071] S1. Prepare a standard working solution of 3-buten-2-ol with a concentration of 0.02 - 0.20 mg / L using N,N-dimethylacetamide as the solvent. The specific steps are as follows:

[0072] S11. Accurately weigh 10 mg (accurate to 0.1 mg) of 3-buten-2-ol standard into a 10 mL brown volumetric flask, and dilute it to the mark with N,N-dimethylacetamide to prepare a 3-buten-2-ol standard stock solution with a concentration of 1000 mg / L. Store it in a refrigerator at 0 - 4°C in the dark and airtight. The validity period is 6 months;

[0073] S12. Accurately pipette 0.1 mL of the 3-buten-2-ol standard stock solution into a 10-mL brown volumetric flask, dilute to the mark with N,N-dimethylacetamide to prepare a 3-buten-2-ol standard intermediate solution with a concentration of 10 mg / L, store it in the dark and airtight in a refrigerator at 0 - 4 °C, and the validity period is 3 months;

[0074] S13. Before use, gradually dilute the standard intermediate solution with N,N-dimethylacetamide to prepare standard working solutions with concentrations of 0.020 mg / L, 0.040 mg / L, 0.080 mg / L, 0.10 mg / L, and 0.20 mg / L;

[0075] S2. Transfer the pretreated simulated material to a headspace vial, add N,N-dimethylacetamide to prepare a sample solution. The simulated material is prepared by the migration experiment of food contact materials and dry food simulants modified polyphenylene oxide;

[0076] Place a sample of a supermarket shopping bag on a glass plate, cover it with the outer lid of a petri dish, cut along the edge of the outer lid with a paper cutter, and prepare 3 samples at the same time. Place them flat inside the inner lids of 3 petri dishes respectively, and calculate the sample surface area based on the area of the inner lid. Cover the surface of the sample evenly with MPPO at a rate of 4 g / dm 2 and cover it completely with the inner lid without spilling outside. After sealing, place it in an environment at 60 °C for 10 d to complete the migration experiment.

[0077] S3. Prepare a method blank sample according to step S2, dissolve the modified polyphenylene oxide in N,N-dimethylacetamide to prepare a blank sample solution;

[0078] S4. Detect the standard working solutions, sample solutions, and blank sample solutions by headspace-gas chromatography / mass spectrometry, and perform quantitative analysis using the peak area. The total ion current chromatogram of 3-buten-2-ol in dry food simulants is as Figure 1 shown.

[0079] The headspace-gas chromatography / mass spectrometry conditions are as follows:

[0080] a) Headspace temperature: 90 °C;

[0081] b) Headspace time: 30 min;

[0082] c) Chromatographic column: 6% cyanopropyl / phenyl 94% dimethyl polysiloxane capillary chromatographic column, 30 m × 0.25 mm × 1.4 μm, or equivalent chromatographic column;

[0083] d) Temperature programming: Hold at 50 °C for 0 min, rise to 100 °C at a rate of 3 °C / min, and hold for 2 min; rise to 250 °C at a rate of 25 °C / min and hold for 1 min.

[0084] e) Injection port temperature: 150 °C;

[0085] f) Column flow rate: 1.0 mL / min;

[0086] g) Injection volume: 1 mL;

[0087] h) Injection mode: Split injection, split ratio 2:1;

[0088] i) Ion source: Electron impact ionization source (EI);

[0089] j) Ion source temperature: 230 °C;

[0090] k) Quadrupole mass analyzer temperature: 150 °C;

[0091] l) Transfer line temperature: 280 °C;

[0092] m) Ionization energy: 70 eV;

[0093] n) Solvent delay: 5.0 min;

[0094] o) Detection mode: SIM (Selected Ion Monitoring mode), qualitative and quantitative ions are shown in Table 1:

[0095] Table 1 Qualitative and quantitative ions of 3-buten-2-ol

[0096] Serial number Compound Quantitative ion (m / z) Qualitative ion (m / z) 1 3-Buten-2-ol 57 43、45、71

[0097] According to the above test conditions, the sample solution and the standard working solution are determined respectively. If the deviation of the retention time of the corresponding chromatographic peaks in the sample solution and the standard solution is within the range of ±0.5%, and in the mass spectrum of the sample solution after background subtraction, the selected ions all appear and the signal-to-noise ratio is not less than 3, the relative abundances of the qualitative ions in the mass spectrum of the sample solution are compared with the relative abundances of the corresponding qualitative ions in the spectrum of the standard solution with a concentration close to that of the sample solution, and the deviation does not exceed the range specified in Table 2, then it can be judged that the corresponding target analyte exists in the sample solution.

[0098] Table 2 Maximum allowable deviation of relative ion abundances

[0099] Relative ion abundance, K / % K≥50 20＜K＜50 10＜K≤20 K≤10 Maximum allowable deviation / % ±10 ±15 ±20 ±50

[0100] Under the above-mentioned determination conditions, the standard working solution (0.020 mg / L - 0.20 mg / L) was detected. With the concentration of 3-buten-2-ol in modified polyphenylene oxide (MPPO) as the abscissa, with the unit expressed in mg / L, and the average value of the corresponding peak area as the ordinate, a standard working curve was plotted to obtain the linear equation and correlation coefficient. The test results show that there is a good linear relationship between its concentration and the response value. The linear relationship of 3-buten-2-ol is higher than 0.995, and its detection limit is 0.01 mg / L, and the quantification limit is 0.020 mg / L, which can well meet the needs of the test work.

[0101] Table 3 Linear relationship table of 0.020 mg / L - 0.20 mg / L

[0102]

[0103] Blank samples without 3-buten-2-ol were pretreated separately, and three concentration levels of the target substances with concentrations of 0.020 mg / L, 0.10 mg / L, and 0.20 mg / L were prepared for determination. Each level was measured separately 6 times to conduct recovery and precision tests. From the test results, it can be seen that the spiked recovery rate of the migration amount of 3-buten-2-ol in modified polyphenylene oxide (MPPO) determined by this method is between 97.5% and 100.5%, and the relative standard deviation is lower than 8.1%. The method proposed by the present invention has good recovery and precision.

[0104] Table 4 Recovery and precision

[0105]

[0106] In the prior art, the determination of the migration amount of 3-buten-2-ol mainly focuses on aqueous-based simulants, fat-containing food simulants, and chemical alternative solvents. However, all of these methods have the following limitations: for aqueous-based simulants, although they can simulate part of the food environment, the detection effect for dry food contact materials is limited because the migration characteristics of dry foods are quite different from the aqueous-based environment; for fat-containing food simulants, although they can better simulate the migration of fat-containing foods, the simulation effect for dry food simulants is not good, and they may be interfered by the fat components, affecting the sensitivity and accuracy of the detection; for chemical alternative solvents, although they have a certain degree of generality, they may not be able to fully simulate the actual food contact environment, and there is matrix effect interference, resulting in inaccurate detection results. The method proposed by the present invention uses modified polyphenylene oxide (MPPO) as a dry food simulant and combines headspace-gas chromatography / mass spectrometry (HS-GC / MS) for detection, which has the advantages of strong specificity, high sensitivity, strong anti-interference ability, and high reliability.

[0107] Comparative Example 1: Detection method for aqueous-based simulant

[0108] Test object: Water was used as a food simulant, and the migration amount of 3-buten-2-ol was detected according to the method of Example 1.

[0109] Result: Since the water-based simulant is quite different from the dry food environment, the detection sensitivity is low, and it cannot accurately reflect the true migration of 3-buten-2-ol in dry food contact materials. In addition, the water-based simulant cannot effectively adsorb and extract the target substance, resulting in a high detection limit.

[0110] Comparative Example 2: Detection method for food simulant containing oils and fats

[0111] Test object: A food simulant containing oils and fats (olive oil) was used, and the migration amount of 3-buten-2-ol was detected according to the method of Example 1.

[0112] Result: Although the oil-based simulant can simulate some migration characteristics, due to its complex chemical composition, it interferes with the detection signal, resulting in an enhanced matrix effect and reducing the detection sensitivity and accuracy. At the same time, the processing process of the oil-based simulant is relatively complex, increasing the detection cost and operation difficulty.

[0113] Comparative Example 3: Detection method for chemical alternative solvents

[0114] Test object: Chemical alternative solvents (95% ethanol and isooctane) were used, and the migration amount of 3-buten-2-ol was detected according to the method of Example 1.

[0115] Result: Although the chemical alternative solvents have a certain degree of generality, they cannot fully simulate the actual migration environment of dry foods, resulting in a large deviation between the detection results and the actual situation. In addition, the chemical alternative solvents may interact with food contact materials, affecting the extraction efficiency of the target substance and the accuracy of the detection results.

[0116] Example 2:

[0117] Same as Example 1, except that the solvents are N,N-dimethylformamide or dimethyl sulfoxide.

[0118] By analyzing the spectra obtained in Example 1 and Example 2, when N,N-dimethylacetamide is used as the solvent, matrix interference can be effectively eliminated. There is no need to use modified polyphenylene oxide (MPPO) to prepare the corresponding standard curve. The standard curve can be directly prepared by diluting with N,N-dimethylacetamide, and accurate quantification of 3-buten-2-ol in modified polyphenylene oxide (MPPO) can be achieved.

[0119] Example 3:

[0120] Same as Example 1, except that the headspace temperature is 85 °C and the equilibrium time is 35 min.

[0121] Example 4:

[0122] Same as Example 1, except that the headspace temperature is 95 °C and the equilibration time is 30 min.

[0123] Comparing Examples 1, 3, and 4, the response of 3-buten-2-ol on the instrument generally increases gradually with the increase of temperature and then tends to be stable. When the headspace temperature increases, the residue amount of high-boiling solvents at the instrument injection port end, chromatographic column, etc. will also increase. The headspace temperature is selected as 90 °C and the equilibration time is 30 min.

[0124] Example 5:

[0125] Same as Example 1, except that the injection port temperatures are 100 °C, 200 °C, and 250 °C respectively.

[0126] Comparing Example 1 and Example 5, for these 4 different injection port temperatures, the peak area of the target compound increases with the increase of the injection port temperature. When the injection port temperature reaches 150 °C, the response reaches the maximum value. After that, the increase in the peak area response with the increase of the injection port temperature is not significant. Considering comprehensive factors such as instrument energy consumption, the injection port temperature is finally set at 150 °C.

[0127] Example 6:

[0128] Same as Example 1, except that the injection mode is splitless injection.

[0129] Example 7:

[0130] Same as Example 1, except that the injection mode is split injection and the split ratio is 1:1.

[0131] Example 8:

[0132] Same as Example 1, except that the injection mode is split injection and the split ratio is 5:1.

[0133] Example 9:

[0134] Same as Example 1, except that the injection mode is split injection and the split ratio is 10:1.

[0135] After the determination of Examples 1 and 6 - 9 on the instrument, it is found that when the split ratio is 2:1, the peak shape of the 3-buten-2-ol chromatographic peak is the best. Therefore, the injection mode is selected as the split mode (split ratio of 2:1), and the headspace injection volume is 1 mL.

[0136] Example 10:

[0137] Same as Example 1, except that the chromatographic column is a weakly polar DB-5MS or a strongly polar HP-INNOWax capillary chromatographic column.

[0138] Comparing Example 1 with Example 10, and contrasting the weakly polar DB-5MS, medium polar DB-624 and strongly polar HP-INNOWax capillary chromatographic columns, it is found that the separation effect of the DB-624 (30m×0.25mm×1.4μm) chromatographic column in Example 1 is the best.

[0139] Example 11:

[0140] Same as Example 1, except that the flow rates of the chromatographic column are 0.5 mL / min, 1.0 mL / min, and 1.5 mL / min respectively.

[0141] Comparing Example 1 with Example 11, when the flow rate of the chromatographic column is low, the peak emergence time is late; when the flow rate of the chromatographic column is high, the peak emergence time is too early. Whether the flow rate of the chromatographic column is too high or too low will affect the column efficiency. Selecting a column flow rate of 1.0 mL / min in Example 1 is the best.

[0142] To further illustrate the universality and applicability of the method of the present invention, the following experiments are carried out for different food contact material samples:

[0143] Example 12: Rubber products for food contact

[0144] Detection object: Silicone rubber food seal

[0145] Migration experiment:

[0146] 1. Cut the silicone rubber seal into small pieces and lay them flat on the bottom of the container, and calculate the bottom area.

[0147] 2. Uniformly cover MPPO in an amount of 4 g / dm 2 , seal it and place it in an environment of 40 °C for migration for 10 days.

[0148] 3. After the migration is completed, transfer the MPPO to a headspace vial, add N,N-dimethylacetamide as a solvent to prepare a sample solution.

[0149] 4. Use the detection method of Example 1 for detection.

[0150] Detection result: The detection result shows that the migration amount of 3-buten-2-ol in the silicone rubber seal is <0.01 mg / kg, meeting the limit requirements, indicating that the rubber product is safe and reliable.

[0151] Example 13: Coating materials for food contact

[0152] Detection object: Inner wall of polyurethane-coated food can

[0153] Migration experiment:

[0154] 1. Scrape the coating sample from the inner wall of the food can, lay it flat on the glass plate, cover it with the outer cover of the petri dish, and cut along the edge of the outer cover to prepare 3 specimens.

[0155] 2. Uniformly cover MPPO on the surface of the specimen at a rate of 4 g / dm 2 . Cover it with the inner cover, seal it, and place it in an environment of 40 °C for 10 days of migration.

[0156] 3. After the migration is completed, transfer MPPO to a headspace bottle, add N,N-dimethylacetamide as a solvent to prepare a sample solution.

[0157] 4. Use the detection method of Example 1 for detection.

[0158] Detection result: The detection result shows that the migration amount of 3-buten-2-ol in the polyurethane coating is <0.01 mg / kg, indicating that the coating material is safe and reliable.

[0159] The method proposed by the present invention is not only applicable to common plastics, but also can effectively detect the migration amount of 3-buten-2-ol in food contact materials such as rubber and coatings. The above examples further prove the universality and reliability of the method of the present invention, and can provide strong technical support for the safety assessment of food contact materials.

[0160] The description of the above embodiments is only used to help understand the technical solution and its core idea of the present invention. It should be pointed out that for those skilled in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. Method for determining the migration amount of 3-buten-2-ol in food contact materials and articles using dry food simulants, characterized in that, It includes the following steps: S1. Dissolve 3-buten-2-ol in a solvent to prepare a standard working solution of 3-buten-2-ol with a concentration of 0.02 - 0.20 mg / L. The solvent is selected from one of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide; S2. Transfer the pretreated simulated material to a headspace vial, add the solvent to prepare a sample solution. The simulated material is prepared by a migration experiment of a food contact material and a dry food simulant modified polyphenylene ether. The solvent is the same as that in step S1; S3. Dissolve the dry food simulant modified polyphenylene ether in the solvent to prepare a blank sample solution. The solvent is the same as that in step S1; S4. Detect the standard working solution, sample solution, and blank sample solution by headspace-gas chromatography / mass spectrometry, and perform quantitative analysis using the peak area.

2. The method according to claim 1, wherein The standard working solution in step S1 is specifically prepared as follows: S11. Weigh the 3-buten-2-ol standard product and prepare a standard stock solution of 3-buten-2-ol with a concentration of 1000 mg / L; S12. Pipette the 3-buten-2-ol standard stock solution into a volumetric flask, and make up to the mark with the solvent to prepare a standard intermediate solution of 3-buten-2-ol with a concentration of 10 mg / L; S13. Then, serially dilute the standard intermediate solution with the solvent to prepare a standard working solution of 3-buten-2-ol with a concentration of 0.02 - 0.20 mg / L. The concentrations of the standard working solution are 0.020 mg / L, 0.040 mg / L, 0.080 mg / L, 0.10 mg / L, and 0.20 mg / L respectively.

3. The method according to claim 1, wherein The migration experiment described in step S2 is specifically as follows: The modified polyphenylene ether is covered on the surface of food contact materials and articles in an amount of 3.5 - 4.5 g / dm 2 . After sealing, it is placed in an environment of 40°C - 60°C for 10 days to complete the migration experiment.

4. The method according to claim 3, characterized in that, The migration experiment described in step S2 is specifically as follows: The modified polyphenylene ether is covered on the surface of food contact materials and articles in an amount of 4 g / dm 2 , and after sealing, it is placed in an environment of 60 °C for 10 d to complete the migration experiment.

5. The method according to claim 1, characterized in that, The working parameters of the headspace-gas chromatography / mass spectrometry in step S4 are as follows: a) Headspace temperature: 85°C - 95°C; b) Headspace time: 25 - 35 min; c) Chromatographic column: 6% cyanopropyl / phenyl 94% dimethyl polysiloxane capillary column, 30 m × 0.25 mm × 1.4 μm, or an equivalent chromatographic column; d) Temperature programming: Hold at 50°C for 0 min, increase to 100°C at a rate of 3°C / min, and hold for 2 min; increase to 250°C at a rate of 25°C / min and hold for 1 min; e) Injector temperature: 100°C - 250°C; f) Column flow rate: 0.5 - 1.5 mL / min; g) Injection volume: 1 mL; h) Injection mode: Split injection, split ratio is 2:1; i) Ion source: Electron impact ionization source EI; j) Ion source temperature: 230°C; k) Quadrupole mass analyzer temperature: 150°C; l) Transfer line temperature: 280°C; m) Ionization energy: 70 eV; n) Solvent delay: 5.0 min; o) Detection mode: SIM selected ion monitoring mode.

6. The method according to claim 5, wherein The working parameters of the headspace-gas chromatography / mass spectrometry in step S4 are as follows: a) Headspace temperature: 90°C; b) Headspace time: 30 min; c) Chromatographic column: 6% cyanopropyl / phenyl 94% dimethyl polysiloxane capillary column, 30 m × 0.25 mm × 1.4 μm, or an equivalent chromatographic column; d) The temperature increase program is as follows: maintain at 50°C for 0 min, increase to 100°C at a rate of 3°C / min, and maintain for 2 min; then increase to 250°C at a rate of 25°C / min and maintain for 1 min. e) Injector temperature: 150°C; f) Column flow rate: 1.0 mL / min; g) Injection volume: 1 mL; h) Injection mode: split injection, split ratio is 2:1; i) Ion source: electron impact ionization source EI; j) Ion source temperature: 230°C; k) Quadrupole mass analyzer temperature: 150°C; l) Transfer line temperature: 280°C; m) Ionization energy: 70 eV; n) Solvent delay: 5.0 min; o) Detection mode: SIM selected ion monitoring mode.

7. The method according to claim 5 or 6, characterized in that, In step S4, the quantitative ion of 3-buten-2-ol is m / z 57, and the qualitative ions are m / z 43, m / z 45, and m / z 71.

8. The method according to claim 1, wherein The specific steps for quantitative analysis of it using the peak area in step S4 are as follows: detect the standard working solution by headspace-gas chromatography / mass spectrometry, draw a standard working curve, then detect the sample solution and the blank sample solution by headspace-gas chromatography / mass spectrometry to obtain the peak area of the chromatographic peak of the target analyte to be measured. According to the standard working curve, calculate the concentrations of 3-buten-2-ol in the sample solution and the blank sample solution, so as to obtain the migration amount of 3-buten-2-ol in the food contact material.

9. The method according to claim 8, wherein The said standard working curve is drawn with the concentration of 3-buten-2-ol in the simulated material as the abscissa, with the unit of mg / kg, and the average value of the corresponding peak area as the ordinate.

10. The application of the method according to claim 1 in determining the migration amount of 3-buten-2-ol in food contact materials and articles.

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