Method for determining migration volume of 2-(dimethylamino) ethanol in food contact material and product by using dry food simulant

Abstract

The invention discloses a method for determining the migration volume of 2-(dimethylamino) ethanol in a food contact material and a food contact product by using a dry food simulant. The method comprises the following steps: (1) preparing a standard working solution of 2-(dimethylamino) ethanol by taking methanol as a solvent; (2) dissolving the pretreated simulation material in methanol to prepare a sample solution, wherein the simulation material is prepared from a food contact material and dry food simulant modified polyphenyl ether through a migration experiment; (3) dissolving the dry food simulant modified polyphenyl ether in methanol to prepare a blank sample solution; and (4) detecting the standard working solution, the sample solution and the blank sample solution by high performance liquid chromatography-tandem mass spectrometry, and qualitatively and quantitatively analyzing the migration volume of 2-(dimethylamino) ethanol in the food contact material and the product. The method provided by the invention makes up the blank of measurement of the migration amount of 2-(dimethylamino) ethanol in a food contact material and a product in a dry food simulant.

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 2-(dimethylamino)ethanol in food contact materials and articles by using a dry food simulant. Background Art:

[0002] 2-(Dimethylamino)ethanol is a widely used organic chemical raw material, used as a raw material for medicine, an intermediate for manufacturing dyes, fiber treatment agents, anti-corrosion additives, etc., and can be used as a water-soluble coating base material, a synthetic resin solvent, etc. 2-(Dimethylamino)ethanol can be used as a raw material or additive for food contact coatings, adhesives or paper products. If the production process is not up to standard, it may lead to residues in the products and migrate into food through contact with food, thereby posing a threat to human health. The specific migration limit (SML) of 2-(dimethylamino)ethanol is clearly specified as 18 mg / kg in the Chinese standard GB 9685-2016.

[0003] At present, the detection method for the migration amount of 2-(dimethylamino)ethanol in modified polyphenylene ether (MPPO) has obvious lag, and there is no report on the analysis and detection method or related standard of this substance in paper products, which cannot meet the requirements of increasingly strict regulations or hygiene standards. Summary of the Invention:

[0004] The present invention solves the problem of the lack of a detection method for the target substance in dry food simulants in the prior art, and provides a method for determining the migration amount of 2-(dimethylamino)ethanol 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 2-(dimethylamino)ethanol in food contact materials and articles in dry food simulants, 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 2-(dimethylamino)ethanol in food contact materials and articles by using a dry food simulant, comprising the following steps:

[0006] (1) Using methanol as a solvent, preparing a standard working solution of 2-(dimethylamino)ethanol with a concentration of 0.03 - 0.30 mg / kg;

[0007] (2) Dissolving the pretreated simulated material in methanol to prepare a sample solution, where the simulated material is prepared by a migration experiment with a food contact material and a dry food simulant modified polyphenylene ether;

[0008] (3) Dissolving the dry food simulant modified polyphenylene ether in methanol to prepare a blank sample solution;

[0009] (4) Detect the standard working solution, sample solution and blank sample solution by high performance liquid chromatography-tandem mass spectrometry to qualitatively and quantitatively analyze the migration amount of 2-(dimethylamino)ethanol in food contact materials and articles.

[0010] The technical route adopted by the method proposed in the present invention is as follows: using modified polyphenylene oxide (MPPO) as a food simulant for migration experiments. After the target substances migrated from the food contact materials and articles are adsorbed by MPPO, they are extracted by ultrasonic waves with an organic solvent. After filtration, the filtrate is blown to dryness with nitrogen, redissolved with methanol and then detected by machine. It is determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS), and quantified by the external standard method of peak area.

[0011] Preferably, the migration experiment described in step (2) is specifically: covering the surface of the food contact material with modified polyphenylene oxide in an amount of 3.5 - 4.5 g / dm 2 , sealing it, and placing it in an environment of 70°C - 80°C for 2 - 3 h to complete the migration experiment.

[0012] More preferably, the migration experiment described in step (2) is specifically: covering the surface of the food contact material with modified polyphenylene oxide in an amount of 4 g / dm 2 , sealing it, and placing it in an environment of 70°C for 2 h to complete the migration experiment.

[0013] For bag-like specimens, place the specimens on a glass plate, cover them with the outer cover of a petri dish, 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, divide 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.

[0014] Preferably, the pretreatment described in step (2) is specifically: after the migration experiment, take out the simulation material and place it in an extraction solvent for ultrasonic extraction for 0.5 - 1.5 hours. After filtration, the filtrate is blown to dryness with nitrogen.

[0015] More preferably, the extraction solvent is selected from one of n-hexane, ethyl acetate and tert-butyl methyl ether, and ultrasonic extraction is carried out for 1 hour.

[0016] Preferably, the working parameters of high performance liquid chromatography-tandem mass spectrometry in step (4) are:

[0017] Chromatographic conditions: Chromatographic column ZORBAX SB-Aq, 150 mm * 4.6 mm * 3.5 μm; Mobile phase A: 0.1% formic acid aqueous solution; Mobile phase B: methanol; Flow rate: 0.40 mL / min; Column temperature: 40 °C; Injection volume: 2 μL; Isocratic elution, elution program: 0 - 5 minutes, 20% mobile phase B, 80% mobile phase A;

[0018] Mass spectrometry conditions: Scanning mode: Multiple reaction monitoring (MRM); Spray voltage: 3500 V; Nebulizing gas pressure GS1: 35 psi; Auxiliary gas temperature 300 °C; Gas flow rate: 9 L / min.

[0019] Preferably, the characteristic ions for qualitative determination by selected ion method in step (4): Quantitative ion m / z 72 and qualitative ion m / z 45 of 2-(dimethylamino)ethanol.

[0020] Preferably, external standard method is adopted for quantitative determination in step (4). The specific steps are as follows: Detect the standard working solution by high performance liquid chromatography-tandem mass spectrometry, draw a standard working curve, then detect the sample solution and blank sample solution by high performance liquid chromatography-tandem mass spectrometry, obtain the peak area of the chromatographic peak of the target analyte to be measured, and calculate the concentrations of 2-(dimethylamino)ethanol in the sample solution and blank sample solution according to the standard working curve, so as to obtain the migration amount of 2-(dimethylamino)ethanol in food contact materials.

[0021] More preferably, the standard working curve is drawn with the concentration of 2-(dimethylamino)ethanol in modified polyphenylene oxide as the abscissa, with the unit of mg / kg, and the average value of the corresponding peak area as the ordinate.

[0022] The present invention also protects the application of the above method in the determination of the migration amount of 2-(dimethylamino)ethanol in food contact materials and articles. Based on the technology of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS), the present invention studies the migration amount of 2-(dimethylamino)ethanol in modified polyphenylene oxide (MPPO), and establishes an accurate and efficient qualitative and quantitative detection technology to achieve the rapid identification and accurate determination of this substance.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. There is no report on the detection technology for the migration amount of 2-(dimethylamino)ethanol in modified polyphenylene oxide (MPPO) at home and abroad at present. The present invention makes up for the blank in the determination of the migration amount of the target analyte in dry food simulants in food contact materials and articles.

[0025] 2. The method proposed by the present invention optimizes the extraction solvent, selects n-hexane with a better average recovery rate of the target substance, and n-hexane is easy to recycle and has economic benefits.

[0026] 3. The liquid chromatography-tandem mass spectrometry method proposed by the present invention for detecting 2-(dimethylamino)ethanol in modified polyphenylene ether has the advantages of good separation effect, high sensitivity and good selectivity, and has a very broad application prospect.

[0027] 4. The spiked recovery rate of the method proposed by the present invention for determining the migration amount of 2-(dimethylamino)ethanol in modified polyphenylene ether (MPPO) is between 98% and 103%, and the relative standard deviation is between 3.5% and 7.9%, with good recovery rate and precision. Description of the drawings:

[0028] Figure 1 It is the total ion current chromatogram of 2-(dimethylamino)ethanol in the dry food simulant in Example 1. Detailed implementation manners:

[0029] The following examples are further descriptions of the present invention, rather than limitations on the present invention.

[0030] 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.

[0031] In the following examples, the migration experiment steps of food contact materials and articles are as follows: For bag-like specimens, place the specimens on a glass plate, cover them with the outer cover of a petri dish, cut along the edge of the outer cover with a paper cutter, and prepare 3 specimens at the same time. Place 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 specimen evenly with MPPO in an amount of 3.5 - 4.5 g / dm 2 , and cover it 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 3.5 - 4.5 g / dm 2 ; if the specimen is irregular and has no flat surface, a suitable method needs to be found to make the specimen fully contact with 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 that the sample is completely covered. After sealing, place it in an environment of 70°C - 80°C for 2 - 3 h to complete the migration experiment.

[0032] Example 1:

[0033] Method for determining the migration amount of 2-(dimethylamino)ethanol in food contact materials and articles using dry food simulants, comprising the following steps:

[0034] (1) Prepare a standard working solution of 2-(dimethylamino)ethanol with a concentration of 0.03 - 0.30 mg / kg using methanol as the solvent;

[0035] (2) Conduct a migration experiment on the bag-like specimen. After the migration experiment, take out the material and ultrasonically extract it with n-hexane for 1 hour. Filter the filtrate and blow it to dry with nitrogen. Then dissolve the pretreated simulant material in methanol to prepare a sample solution with a concentration of 0.03 - 0.30 mg / kg;

[0036] (3) Dissolve the dry food simulant modified polyphenylene ether in methanol to prepare a blank sample solution with a concentration of 0.03 - 0.30 mg / kg;

[0037] (4) Detect the standard working solution, sample solution, and blank sample solution by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS) to qualitatively and quantitatively analyze the migration amount of 2-(dimethylamino)ethanol in food contact materials and articles.

[0038] The working parameters of HPLC-MS / MS are as follows:

[0039] Chromatographic conditions: Chromatographic column: ZORBAX SB-Aq, 150 mm * 4.6 mm * 3.5 μm; Mobile phase A: 0.1% formic acid aqueous solution; Mobile phase B: methanol; Flow rate: 0.40 mL / min; Column temperature: 40 °C; Injection volume: 2 μL; Isocratic elution, elution program: 0 - 5 minutes, 20% mobile phase B, 80% mobile phase A;

[0040] Mass spectrometry conditions: Scanning mode: multiple reaction monitoring (MRM); Spray voltage: 3500 V; Nebulizing gas pressure GS1: 35 psi; Auxiliary gas temperature: 300 °C; Gas flow rate: 9 L / min. The mass spectrometry parameters of the compound are shown in Table 1:

[0041] Table 1

[0042]

[0043] Qualitatively identify by comparing the retention time of the specimen chromatogram with that of the corresponding standard and the characteristic ions of each chromatographic peak with those of the corresponding concentration standard solution. The relative deviation of the retention time between the specimen and the standard should not be greater than 2.5%; if the relative abundance of the characteristic ions of the specimen is consistent with that of the corresponding concentration standard solution and the relative abundance deviation does not exceed the regulations in the following table, it can be determined that 2-(dimethylamino)ethanol exists in the food simulant. As shown in Table 2:

[0044] Table 2 Maximum allowable deviation of relative ion abundance during qualitative determination

[0045] Relative ion abundance ＞50％ 20％～50％ 10％～20％ ≤10％ Allowed relative deviation ±20％ ±25％ ±30％ ±50％

[0046] The specific steps for quantitative determination using the external standard working curve method are as follows: Detect the standard working solution by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS), draw the standard working curve, then detect the sample solution and the blank sample solution by HPLC-MS / MS to obtain the peak areas of the target analytes to be measured. According to the standard working curve, calculate the concentrations of 2-(dimethylamino)ethanol in the sample solution and the blank sample solution, so as to obtain the migration amount of 2-(dimethylamino)ethanol in the food contact material. The standard working curve is drawn with the concentration of 2-(dimethylamino)ethanol in the modified polyphenylene ether as the abscissa, with the unit expressed in mg / kg, and the average value of the corresponding peak areas as the ordinate. As shown in Table 3, X = 0.03 - 0.3 mg / kg.

[0047] Table 3

[0048]

[0049] The test results in Table 3 show that there is a good linear relationship between the concentration and the response value. The linear relationship of 2-(dimethylamino)ethanol is higher than 0.995, and its detection limit is 0.01 mg / kg, and the quantification limit is 0.03 mg / kg, which can well meet the needs of the test work.

[0050] Prepare blank sample solutions with three concentration levels of the target analytes at 0.030 mg / kg, 0.15 mg / kg, and 0.30 mg / kg, and perform 6 individual determinations for each level to conduct the recovery and precision tests. The results are shown in Table 4:

[0051] Table 4

[0052]

[0053] It can be seen from the test results that the spiked recoveries of the method for determining the migration amount of 2-(dimethylamino)ethanol in modified polyphenylene ether (MPPO) are between 98.9% and 102.2%, and the relative standard deviations are between 3.5% and 7.9%, indicating that this method has good recoveries and precision.

[0054] Example 2:

[0055] Same as Example 1, the difference is that the extraction solvent is ethyl acetate.

[0056] Example 3:

[0057] Same as Example 1, the difference is that the extraction solvent is tert-butyl methyl ether.

[0058] The recovery rates with extraction solvents being n-hexane, ethyl acetate, and tert-butyl methyl ether (Examples 1-3) are shown in Table 5 as follows:

[0059] Table 5

[0060]

[0061] As can be seen from Table 5, the average spiked recovery rate of the migration amount of 2-(dimethylamino)ethanol with n-hexane as the extraction solvent reaches 102.2%, which is higher than 77.8% and 75.6% of ethyl acetate and tert-butyl methyl ether.

[0062] Example 4: Determination of paper products

[0063] Same as Example 1, except that the sample is a composite cardboard containing an adhesive.

[0064] Blank sample solutions were prepared at three concentration levels of the target substance at 0.030 mg / kg, 0.15 mg / kg, and 0.30 mg / kg, and each level was measured separately 6 times for recovery rate and precision tests. The results are shown in Table 6 as follows:

[0065] Table 6

[0066]

[0067] From the test results, it can be seen that the spiked recovery rate of the migration amount of 2-(dimethylamino)ethanol in modified polyphenylene ether (MPPO) determined by this method is between 91.7% and 94.4%, and the relative standard deviation is between 1.8% and 2.6%, indicating that this method has good recovery rate and precision for adhesive samples.

[0068] Example 5: Determination of coatings and paints

[0069] Same as Example 1, except that the sample is a coated can.

[0070] Blank sample solutions were prepared at three concentration levels of the target substance at 0.030 mg / kg, 0.15 mg / kg, and 0.30 mg / kg, and each level was measured separately 6 times for recovery rate and precision tests. The results are shown in Table 7 as follows:

[0071] Table 7

[0072]

[0073] From the test results, it can be seen that the spiked recovery rate of the migration amount of 2-(dimethylamino)ethanol in modified polyphenylene ether (MPPO) determined by this method is between 97.8% and 105.0%, and the relative standard deviation is between 3.0% and 5.4%, indicating that this method has good recovery rate and precision for coated samples.

[0074] 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 noted that for those skilled in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can still 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 2-(dimethylamino)ethanol in food contact materials and articles using dry food simulants, characterized in that, It includes the following steps: (1) Using methanol as a solvent, prepare a standard working solution of 2-(dimethylamino)ethanol with a concentration of 0.03 - 0.30 mg / kg. (2) Dissolve the pretreated simulated material in methanol to prepare a sample solution. The simulated material is obtained by a migration experiment with a food contact material and a dry food simulant, modified polyphenylene ether. (3) Dissolve the dry food simulant, modified polyphenylene ether, in methanol to prepare a blank sample solution. (4) Use high performance liquid chromatography-tandem mass spectrometry to detect the standard working solution, the sample solution, and the blank sample solution, and conduct qualitative and quantitative analysis of the migration amount of 2-(dimethylamino)ethanol in food contact materials and articles.

2. The method according to claim 1, wherein The migration experiment described in step (2) is specifically as follows: The modified polyphenylene ether is covered on the surface of the food contact material in an amount of 3.5-4.5 g / dm 2 . After sealing, it is placed in an environment of 70°C - 80°C for 2 - 3 h to complete the migration experiment.

3. The method according to claim 1 or 2, characterized in that The specific pretreatment in step (2) is as follows: After the migration experiment, take out the simulated material, place it in an extraction solvent, and ultrasonically extract for 0.5 - 1.5 hours. After filtration, blow the filtrate to dryness with nitrogen.

4. The method according to claim 3, characterized in that, The extraction solvent is selected from one of n-hexane, ethyl acetate, and tert-butyl methyl ether.

5. The method according to claim 1, wherein The working parameters of high performance liquid chromatography-tandem mass spectrometry in step (4) are as follows: Chromatographic conditions: Chromatographic column ZORBAX SB-Aq, 150 mm * 4.6 mm * 3.5 μm; Mobile phase A: 0.1% formic acid aqueous solution; Mobile phase B: methanol; Flow rate: 0.40 mL / min; Column temperature: 40 °C; Injection volume: 2 μL; Isocratic elution, elution program: 0 - 5 minutes, 20% mobile phase B, 80% mobile phase A. Mass spectrometry conditions: Scanning mode: Multiple reaction monitoring MRM; Spray voltage: 3500 V; Nebulizing gas pressure GS1: 35 psi; Auxiliary gas temperature 300 °C; Gas flow rate: 9 L / min.

6. The method according to claim 1 or 5, characterized in that, The characteristic ions for qualitative determination using multiple reaction monitoring MRM in step (4): The quantitative ion of 2-(dimethylamino)ethanol is m / z 90→72, and the qualitative ion is m / z 90→45.

7. The method according to claim 1 or 5, characterized in that Step (4) uses the external standard method for quantitative determination. The specific steps are as follows: Use high performance liquid chromatography-tandem mass spectrometry to detect the standard working solution, draw a standard working curve, then use high performance liquid chromatography-tandem mass spectrometry to detect the sample solution and the blank sample solution, obtain the peak area of the chromatographic peak of the target analyte to be measured, and calculate the concentration of 2-(dimethylamino)ethanol in the sample solution and the blank sample solution according to the standard working curve, so as to obtain the migration amount of 2-(dimethylamino)ethanol in food contact materials and articles.

8. The method according to claim 7, wherein The standard working curve is drawn with the concentration of 2-(dimethylamino)ethanol in the modified polyphenylene ether as the abscissa, with the unit expressed in mg / kg, and the average value of the corresponding peak area as the ordinate.

9. Application of the method according to claim 1 in the determination of the migration amount of 2-(dimethylamino)ethanol in food contact materials and articles.

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