Method for determining 9, 9-dimethoxymethylfluorene in food simulation liquid

Abstract

The invention provides a method for determining 9, 9-dimethoxymethylfluorene in food simulation liquid, which comprises the following steps: sampling and detecting the content of 9, 9-dimethoxymethylfluorene in a sample solution, the step of detecting the content of the 9, 9-dimethoxymethylfluorene in the sample solution comprises the following steps: determining the content of the 9, 9-dimethoxymethylfluorene in the sample solution by using a gas chromatography-mass spectrometer; wherein the determination conditions of the gas chromatography-mass spectrometer are as follows: a chromatographic column is DB-5MS; the flow velocity of the carrier gas is 1mL / min; the sample size is 1 [mu] L; the temperature of a sample inlet is 280 DEG C; the initial temperature of the column box is 90 DEG C, the initial temperature is kept for 2 min, and then the initial temperature is increased to 310 DEG C at the speed of 20 DEG C / min and kept for 0 min; quantitative ions: 178; and qualitative ions: 254, 165 and 194. According to the method, the 9, 9-dimethoxymethylfluorene in the food simulation liquid is detected by adopting the gas chromatography-mass spectrometer, the recovery rate reaches 98-107%, the detection limit can reach 0.05 mg / kg, the operation is simple, the used equipment is easy to obtain, and the method has high generalizability.

Description

Technical Field

[0001] The present application relates to the field of consumer product testing, and in particular to a method for determining 9,9-dimethoxymethylfluorene in a food simulation liquid. Background Art

[0002] 9,9-Bis(methoxymethyl)fluorene (BMMF) is an organic catalyst commonly used in the synthesis of polypropylene, so it is easy for this substance to remain in polypropylene materials. According to the research results of the European Chemicals Agency (ECHA), this substance has extremely high aquatic toxicity and is irritating to the human body. Therefore, the EU has included this substance in the scope of control and stipulated that its use in food contact materials is restricted, requiring that its concentration shall not exceed 0.05mg / kg after contact with food simulant liquid.

[0003] At present, the testing method for 9,9-bismethoxymethylfluorene is still in a blank stage, and it is imperative to establish an efficient and reliable detection technology for 9,9-bismethoxymethylfluorene in food simulation liquid. Summary of the invention

[0004] In view of the above problems, the present application is proposed to provide a method for determining 9,9-bismethoxymethylfluorene in a food simulation liquid to overcome the above problems or at least partially solve the above problems, comprising:

[0005] A method for determining 9,9-bismethoxymethylfluorene in a food simulation solution comprises the steps of: sampling and detecting the content of 9,9-bismethoxymethylfluorene in the sample solution;

[0006] The step of detecting the content of 9,9-bismethoxymethylfluorene in the sample solution comprises:

[0007] The content of 9,9-bismethoxymethylfluorene in the sample solution was determined using a gas chromatography-mass spectrometer; wherein the determination conditions of the gas chromatography-mass spectrometer were:

[0008] Chromatographic column: DB-5MS;

[0009] Carrier gas flow rate 1 mL / min;

[0010] Injection volume: 1uL;

[0011] Inlet temperature: 280°C;

[0012] Column box temperature: initial temperature 90°C, hold for 2 min, then increase to 310°C at 20°C / min, hold for 0 min;

[0013] Quantitative ions: 178; Qualifying ions: 254, 165, 194.

[0014] Furthermore, the sampling step comprises:

[0015] Take a first volume of the sample solution into a glass test tube.

[0016] Furthermore, the sample solution is an aqueous simulated liquid or a fat substitute.

[0017] Furthermore, when the sample solution is an aqueous simulated liquid, the step of using a gas chromatography-mass spectrometer to determine the content of 9,9-bismethoxymethylfluorene in the sample solution comprises:

[0018] Adding a specified mass of sodium chloride to the sample solution and fully dissolving it to obtain a mixed solution;

[0019] Add a second volume of toluene to the mixed solution, shake and take the upper toluene layer as the test solution for the machine;

[0020] The content of 9,9-bismethoxymethylfluorene in the test solution was determined by gas chromatography-mass spectrometry.

[0021] Furthermore, the specified mass is 1-5g.

[0022] Furthermore, a volume ratio of the first volume to the second volume is 1:1.

[0023] Furthermore, the step of adding a second volume of toluene to the mixed solution, shaking and taking an upper toluene layer as a test solution for the machine comprises:

[0024] A second volume of toluene was added to the mixture, and the mixture was shaken vigorously for 30 seconds, and then continued to shake on the shaker for 30 minutes.

[0025] Furthermore, when the sample solution is a fat substitute, a gas chromatography-mass spectrometer is directly used to determine the content of 9,9-bismethoxymethylfluorene in the fat substitute.

[0026] Furthermore, the aqueous simulated liquid is water, 3% acetic acid, 10% ethanol, 20% ethanol or 50% ethanol.

[0027] This application has the following advantages:

[0028] In the embodiments of the present application, compared with the prior art which is still at a blank stage in the detection of 9,9-bismethoxymethylfluorene in food simulant liquid, the present application provides a solution for detecting 9,9-bismethoxymethylfluorene in food simulant liquid by gas chromatography-mass spectrometry, specifically: sampling and detecting the content of 9,9-bismethoxymethylfluorene in the sample solution; the step of detecting the content of 9,9-bismethoxymethylfluorene in the sample solution comprises: using a gas chromatography-mass spectrometer to determine the content of 9,9-bismethoxymethylfluorene in the sample solution; wherein the determination conditions of the gas chromatography-mass spectrometer are: chromatographic column: DB-5MS; carrier gas flow rate 1mL / min; injection volume: 1uL; injection port temperature: 280°C; column box temperature: starting temperature 90°C, after maintaining for 2min, increase to 310°C at 20°C / min, and maintain for 0min; quantitative ions: 178; qualitative ions: 254, 165, 194. The present invention adopts gas chromatography-mass spectrometer to detect 9,9-dimethoxymethylfluorene in food simulation liquid, with a recovery rate of 98-107% and a detection limit of 0.05 mg / kg. The operation is simple, the equipment used is easy to obtain, and the invention is highly scalable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the description of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 This is a flow chart of the steps of a method for determining 9,9-bismethoxymethylfluorene in a food simulation liquid provided in one embodiment of the present application;

[0031] Figure 2 This is a chromatogram of 9,9-bismethoxymethylfluorene provided in one embodiment of the present application;

[0032] Figure 3 This is a mass spectrum of 9,9-bismethoxymethylfluorene provided in one embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the objects, features and advantages of the present application more obvious and understandable, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0034] The inventors found through analysis of the prior art that after a certain pretreatment of the sample to be tested, the content of 9,9-bismethoxymethylfluorene in the food simulation liquid can be determined by using a gas chromatography-mass spectrometer by studying instrument parameters and improving instrument methods.

[0035] Reference Figure 1 , showing a method for determining 9,9-bismethoxymethylfluorene in a food simulation liquid provided in one embodiment of the present application;

[0036] The method comprises: S1, sampling and S2, detecting the content of 9,9-bismethoxymethylfluorene in the sample solution;

[0037] The step of detecting the content of 9,9-bismethoxymethylfluorene in the sample solution comprises:

[0038] S21. Using a gas chromatography-mass spectrometer to determine the content of 9,9-bismethoxymethylfluorene in the sample solution; wherein the determination conditions of the gas chromatography-mass spectrometer are:

[0039] Chromatographic column: DB-5MS;

[0040] Carrier gas flow rate 1 mL / min;

[0041] Injection volume: 1uL;

[0042] Inlet temperature: 280°C;

[0043] Column box temperature: initial temperature 90°C, hold for 2 min, then increase to 310°C at 20°C / min, hold for 0 min;

[0044] Quantitative ions: 178; Qualifying ions: 254, 165, 194.

[0045] In the embodiments of the present application, compared with the prior art which is still at a blank stage in the detection of 9,9-bismethoxymethylfluorene in food simulant liquid, the present application provides a solution for detecting 9,9-bismethoxymethylfluorene in food simulant liquid by gas chromatography-mass spectrometry, specifically: sampling and detecting the content of 9,9-bismethoxymethylfluorene in the sample solution; the step of detecting the content of 9,9-bismethoxymethylfluorene in the sample solution comprises: using a gas chromatography-mass spectrometer to determine the content of 9,9-bismethoxymethylfluorene in the sample solution; wherein the determination conditions of the gas chromatography-mass spectrometer are: chromatographic column: DB-5MS; carrier gas flow rate 1mL / min; injection volume: 1uL; injection port temperature: 280°C; column box temperature: starting temperature 90°C, after maintaining for 2min, increase to 310°C at 20°C / min, and maintain for 0min; quantitative ions: 178; qualitative ions: 254, 165, 194. The present invention adopts gas chromatography-mass spectrometer to detect 9,9-dimethoxymethylfluorene in food simulation liquid, with a recovery rate of 98-107% and a detection limit of 0.05 mg / kg. The operation is simple, the equipment used is easy to obtain, and the invention is highly scalable.

[0046] Next, the determination method of 9,9-bismethoxymethylfluorene in a food simulation liquid in this exemplary embodiment will be further described.

[0047] As described in step S1, sampling is performed.

[0048] In an embodiment of the present invention, the specific process of “sampling” in step S1 may be further explained in combination with the following description.

[0049] As described in the following steps, a first volume of the sample solution is taken into a glass test tube.

[0050] It should be noted that sampling is generally one of the important steps to extract a small amount of target substance from the target object for testing. It is one of the effective ways to obtain the target object for testing and obtain various data without affecting the main properties of the target object. The amount of the extracted object must be sufficient for 3-5 tests. When sampling, the sampling area selection process for the object to be tested is required to be random, and subjective selection should not be mixed in the selection process.

[0051] As an example, 10 mL of the sample solution is taken into a glass test tube.

[0052] As described in step S2, the content of 9,9-bismethoxymethylfluorene in the sample solution is detected.

[0053] In one embodiment of the present invention, the sample solution is an aqueous simulated liquid or a fat substitute.

[0054] As an example, the aqueous simulated liquid is water, 3% acetic acid, 10% ethanol, 20% ethanol or 50% ethanol; the oil substitute is isooctane.

[0055] When the sample solution is an aqueous simulated liquid, the aqueous simulated liquid needs to be pre-treated before being measured by a gas chromatography-mass spectrometer.

[0056] It should be noted that pretreatment is generally a step to remove impurities and purify the target object before carrying out effective processes. In some special experiments, the pretreatment step also includes the purpose of changing the properties of the substance.

[0057] In one embodiment of the present invention, when the sample solution is an aqueous simulated solution, the step of "determining the content of 9,9-bismethoxymethylfluorene in the sample solution using a gas chromatography-mass spectrometer" is further explained in combination with the following description.

[0058] As described in the following steps, a specified mass of sodium chloride is added to the sample solution and a mixed solution is obtained after the solution is fully dissolved;

[0059] As described in the following steps, a second volume of toluene is added to the mixed solution, and after shaking, the upper toluene layer is taken as the test solution for the machine;

[0060] As described in the following steps, the content of 9,9-bismethoxymethylfluorene in the upper machine test solution is determined using a gas chromatography-mass spectrometer.

[0061] In one embodiment of the present invention, the step of adding a second volume of toluene to the mixed solution, shaking and taking an upper toluene layer as a test solution for the machine comprises:

[0062] As described in the following steps, a second volume of toluene was added to the mixture, shaken vigorously for 30 seconds, and then continued to shake on the shaker for 30 minutes.

[0063] It should be noted that the addition of sodium chloride can significantly reduce the solubility of organic matter in the aqueous phase, making 9,9-dimethoxymethylfluorene more inclined to be distributed in toluene. The mixing degree of the sample solution and sodium chloride is sufficient to achieve that the sample solution and sodium chloride are in the same reactor and in contact with each other. Since the solubility of sodium chloride in toluene is extremely low, it helps to form stratification: the upper toluene layer and the lower water layer. Sodium chloride mainly remains in the aqueous phase, making it easier to extract and analyze 9,9-dimethoxymethylfluorene from the toluene layer.

[0064] Toluene, as a non-polar solvent, has a good solubility for 9,9-bismethoxymethylfluorene. During the oscillation process, toluene can effectively extract 9,9-bismethoxymethylfluorene from the aqueous phase, thereby enriching it in the toluene layer.

[0065] In this embodiment, the specified mass is 1-5g.

[0066] In this embodiment, the volume ratio of the first volume to the second volume is 1:1.

[0067] In a specific implementation, 10 ml of sample solution is taken into a glass test tube, 3 g of sodium chloride is added, and 10 ml of toluene is added after dissolution. The sample is shaken vigorously for 30 seconds and then continuously shaken on a shaker for 30 minutes. After the shaking, the upper toluene layer is taken and analyzed and quantified by gas chromatography-mass spectrometry.

[0068] In one embodiment of the present invention, when the sample solution is a fat substitute, a gas chromatography-mass spectrometer is directly used to determine the content of 9,9-bismethoxymethylfluorene in the fat substitute.

[0069] For oil substitutes, no additional treatment is required and they can be directly analyzed and quantified using gas chromatography-mass spectrometry.

[0070] In one embodiment of the present application, a gas chromatography-mass spectrometer is used to determine the content of 9,9-bismethoxymethylfluorene in the sample solution. Generally, a specified experiment or detection step is performed on the sample solution, and direct data or indirect data is generally obtained, wherein direct data is data that directly detects the target value or result; indirect data is data that needs to be calculated, replaced or compared accordingly to obtain the target value or result. The test results generally have deviation values ​​according to the deviations of the test equipment, environment, pretreatment steps and auxiliary products. After the test standards are formulated, the differences in pretreatment and auxiliary products can effectively avoid the error margin caused by them.

[0071] Wherein, the measurement conditions of the gas chromatography-mass spectrometer are:

[0072] Chromatographic column: DB-5MS

[0073] Carrier gas flow rate 1mL / min

[0074] Injection volume: 1uL

[0075] Inlet temperature: 280°C

[0076] Column box temperature:

[0077] Initial: 90℃

[0078] Hold: 2 minutes

[0079] Ramp 1: 20℃ / min

[0080] Setpoint 1: 310℃

[0081] Hold: 0min.

[0082] Mass spectrometry ions:

[0083] BMMF Quantitative ion 178 Qualifier ions 254 Qualifier ions 165 Qualifier ions 194

[0084] Linear range (mg / L): 0.05, 0.1, 0.5; correlation coefficient R2 = 0.995.

[0085] Chromatogram Figure 2 As shown in the mass spectrum Figure 3 shown.

[0086] The following are embodiments of the present invention:

[0087] Through the simulation experiment of typical sample materials, adding a certain amount of target substances to the simulated liquid, and using corresponding equipment for detection and analysis. The details are as follows:

[0088] 1. Sample description: Five food simulants: water, 3% acetic acid, 10% ethanol, 95% ethanol, and isooctane

[0089] 2. Spiking process:

[0090] Take five polypropylene plastic bowls, add a certain volume of the above five simulated liquids respectively, and add an appropriate amount of 1000 mg / L standard stock solution according to the added volume, so that the concentration of 9,9-bismethoxymethylfluorene in the simulated liquid is 0.1 mg / kg, and soak at room temperature for 24 hours.

[0091] After taking out the simulated liquid, for the aqueous simulated liquid (water, 3% acetic acid, 10% ethanol, 95% ethanol), take 10 ml of the solution in a glass test tube, add 3 g of sodium chloride, and then add 10 ml of toluene after dissolving. After vigorous shaking for 30 seconds, continue shaking on a shaker for 30 minutes. After the end, take the upper toluene layer and analyze and quantify it using a gas chromatography-mass spectrometer;

[0092] For oil substitutes, no additional treatment is required and they can be directly analyzed and quantified using gas chromatography-mass spectrometry.

[0093] 3. Spiked recovery rate (%):

[0094] Food Simulator Recovery rate water 102％ 3% acetic acid 100％ 10% ethanol 104％ 20% ethanol 103％ 50% ethanol 107％ 95% ethanol 99％ Isooctane 98％

[0095] Linear range (mg / L): 0.05, 0.1, 0.5ppm; correlation coefficient R2 = 0.995

[0096] Minimum detection limit: 0.05mg / kg (simulated liquid).

[0097] From the above, it can be seen that the recovery rate is 98-107%, which is relatively high, indicating that this method can effectively detect the content of 9,9-bismethoxymethylfluorene in food simulant liquid. The minimum detection limit of 9,9-bismethoxymethylfluorene is 0.05 mg / kg, indicating that this analytical method can effectively separate the target substance from impurities, and the linearity of the target peak in the standard curve is good, indicating that this analytical method is feasible.

[0098] The present application uses sodium chloride and toluene to extract 9,9-bismethoxymethylfluorene in the aqueous simulated liquid, so that 9,9-bismethoxymethylfluorene can be separated from most of the impurities in the aqueous phase, thereby improving the accuracy and sensitivity of subsequent instrumental analysis. By using a gas chromatography-mass spectrometer for qualitative and quantitative detection and analysis, and using optimized specific detection conditions, the content of 9,9-bismethoxymethylfluorene in the food simulated liquid can be efficiently and accurately detected. The method has a low detection limit, is simple to operate, and the equipment used is easy to obtain, and is highly scalable.

[0099] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0100] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0101] The above is a detailed introduction to the method for determining 9,9-dimethoxymethylfluorene in a food simulation liquid provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technicians in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for determining 9,9-bismethoxymethylfluorene in a food simulation liquid, characterized in that: The method comprises the steps of: sampling and detecting the content of 9,9-bismethoxymethylfluorene in a sample solution; The step of detecting the content of 9,9-bismethoxymethylfluorene in the sample solution comprises: The content of 9,9-bismethoxymethylfluorene in the sample solution was determined using a gas chromatography-mass spectrometer; wherein the determination conditions of the gas chromatography-mass spectrometer were: Chromatographic column: DB-5MS; Carrier gas flow rate 1 mL / min; Injection volume: 1uL; Inlet temperature: 280°C; Column box temperature: initial temperature 90°C, hold for 2 min, then increase to 310°C at 20°C / min, hold for 0 min; Quantitative ions: 178; Qualifying ions: 254, 165, 194.

2. The measuring method according to claim 1, characterized in that The sampling step comprises: Take a first volume of the sample solution into a glass test tube.

3. The measuring method according to claim 2, characterized in that The sample solution is an aqueous simulated liquid or a fat substitute.

4. The measuring method according to claim 3, characterized in that When the sample solution is an aqueous simulated liquid, the step of using a gas chromatography-mass spectrometer to determine the content of 9,9-bismethoxymethylfluorene in the sample solution comprises: Adding a specified mass of sodium chloride to the sample solution and fully dissolving it to obtain a mixed solution; Add a second volume of toluene to the mixed solution, shake and take the upper toluene layer as the test solution for the machine; The content of 9,9-bismethoxymethylfluorene in the test solution was determined by gas chromatography-mass spectrometry.

5. The measuring method according to claim 4, characterized in that The specified mass is 1-5 g.

6. The measuring method according to claim 4, characterized in that The volume ratio of the first volume to the second volume is 1:

1.

7. The measuring method according to claim 4, characterized in that The step of adding a second volume of toluene to the mixed solution, shaking and taking the upper toluene layer as the test solution for the machine comprises: A second volume of toluene was added to the mixture, and the mixture was shaken vigorously for 30 seconds, and then continued to shake on the shaker for 30 minutes.

8. The measuring method according to claim 3, characterized in that When the sample solution is a fat substitute, a gas chromatography-mass spectrometer is directly used to determine the content of 9,9-bismethoxymethylfluorene in the fat substitute.

9. The measuring method according to claim 3, characterized in that The aqueous simulated liquid is water, 3% acetic acid, 10% ethanol, 20% ethanol or 50% ethanol.

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