Standard substance for aspartame solution in water as well as preparation method and application of standard substance

Abstract

The embodiment of the invention discloses a standard substance for an aspartame solution in water as well as a preparation method and application of the standard substance, and belongs to the technical field of standard substances. The method comprises the following steps: accurately weighing an aspartame standard substance, adding a diluent to dissolve the aspartame standard substance, transferring the dissolved aspartame standard substance into a volumetric flask, and fixing the volume by using the diluent to prepare an aspartame solution standard substance in water with the concentration of (10-1000) [mu] g / mL, wherein the diluent contains citric acid with the mass concentration of (10.82-15.65) g / L, sodium citrate with the mass concentration of (7.5-14.26) g / L and ascorbic acid with the mass concentration of (1-5) g / L. The stability of the standard substance of the aspartame solution in water can reach 18 months, meanwhile, the quantity value is reliable, and the standard substance can be used under wider conditions, so that the application range of the standard substance is widened.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of reference materials, and particularly to a reference material of aspartame solution in water, a preparation method thereof, and an application thereof. Background Art

[0002] As a widely used non-carbohydrate artificial sweetener, aspartame is widely used in the fields of food, beverages, and pharmaceuticals. However, in order to ensure the accuracy and safety of the aspartame content in foods and pharmaceuticals, reference materials are required for daily analysis, detection, method evaluation, and instrument calibration. Therefore, the preparation of a reference material of aspartame solution in water has become a key link in ensuring food quality and safeguarding consumer rights and interests.

[0003] Aspartame is susceptible to environmental factors such as pH value, temperature, and light in a solution state, which easily causes its decomposition and invalidation. Currently, the reference material of aspartame solution is prepared by dissolving the aspartame reference standard in pure water, and there is still room for improvement in terms of stability. Especially during long-term storage and transportation, aspartame is prone to decomposition, thus affecting the accuracy and reliability of the reference material.

[0004] Therefore, developing a reference material of aspartame solution with good stability can ensure the accuracy and reliability of relevant detection and analysis results, which is of great significance in the fields of food quality control and food safety risk assessment. Summary of the Invention

[0005] For this reason, the embodiments of the present invention provide a reference material of aspartame solution in water, a preparation method thereof, and an application thereof.

[0006] In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

[0007] According to the first aspect of the embodiments of the present invention, the present invention provides a preparation method of a reference material of aspartame solution in water, the method comprising:

[0008] Accurately weigh the aspartame reference standard, dissolve it in a diluent, transfer it to a volumetric flask, and make up the volume with the diluent to prepare an aspartame solution reference material in water with a concentration of (10 - 1000) μg / mL. The diluent contains citric acid with a mass concentration of (10.82 - 15.65) g / L, sodium citrate with a mass concentration of (7.5 - 14.26) g / L, and ascorbic acid with a mass concentration of (1 - 5) g / L.

[0009] Furthermore, the pH value of the diluent is 3.6 - 4.6.

[0010] Further, the preparation method of the diluent is as follows: Dissolve citric acid, sodium citrate, and ascorbic acid in pure water to obtain a solution with the final concentrations of citric acid, sodium citrate, and ascorbic acid being (10.82 - 15.65) g / L, (7.5 - 14.26) g / L, and (1 - 5) g / L, respectively.

[0011] Further, the purity of the aspartame standard is 98% - 100%.

[0012] According to the second aspect of the embodiments of the present invention, the present invention provides a standard substance of aspartame solution in water, which is prepared by the preparation method described in any one of the above.

[0013] According to the third aspect of the embodiments of the present invention, the present invention provides the application of the standard substance of aspartame solution in water as described above, which is used for detecting the content of aspartame in food.

[0014] Further, liquid chromatography - ultraviolet detector is used for detection, and the conditions of liquid chromatography - ultraviolet detection include:

[0015] Mobile phase: The volume ratio of methanol to water is 40:60;

[0016] Chromatographic column: C18, 250 mm × 4.6 mm × 5 μm;

[0017] Detection wavelength: 200 nm;

[0018] Column temperature: 30°C;

[0019] Flow rate: 0.8 mL / min;

[0020] Injection volume: 20 μL.

[0021] The embodiments of the present invention have the following advantages:

[0022] (1) In the preparation method of the standard substance of aspartame solution in water of the present invention, citric acid solution and sodium citrate solution are added to adjust the pH value of the solution, providing a more stable environment for aspartame, preventing it from degrading or deteriorating under adverse conditions, and extending its storage time.

[0023] (2) Ascorbic acid solution is added in the preparation method of the standard substance of aspartame solution in water of the present invention to prevent the oxidation and decomposition of aspartame molecules, further enhancing the stability of the solution.

[0024] (3) The stability of the standard substance of aspartame solution in water of the present invention can last up to 18 months, and at the same time, the quantity value is reliable, and it can be used under a wider range of conditions, thereby broadening its application scope. Description of the Drawings

[0025] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained according to the provided drawings.

[0026] Figure 1 Flow chart of the preparation method of the aspartame solution reference material in water provided by the present invention;

[0027] Figure 2 Standard curve provided by the present invention;

[0028] Figure 3 Stability test chart of the aspartame solution reference material in water provided by the present invention. Specific embodiments

[0029] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0030] Aspartame standard: National Standard Material Center of Tanmo Quality Inspection, 98.4%;

[0031] Citric acid: aladdin, 99%;

[0032] Sodium citrate: aladdin, 98%;

[0033] Ascorbic acid: aladdin, 99.5%.

[0034] As Figure 1 shown, the preparation method of the aspartame solution reference material in water provided by the present invention includes:

[0035] S110. Prepare a dilution solution. The mass concentration of citric acid is (10.82 - 15.65) g / L, the mass concentration of sodium citrate is (7.5 - 14.26) g / L, the mass concentration of ascorbic acid is (1 - 5) g / L, and the pH value of the dilution solution is 3.6 - 4.6.

[0036] S120. Weigh. Use an electronic balance with a precision of one in a hundred thousand that has been calibrated to accurately weigh 1.00000 g to 5.00000 g of aspartame calculated as 100% mass according to the purity.

[0037] S130. Dilution. Dissolve the weighed aspartame standard in the dilution solution prepared in S110.

[0038] S140. Volume fixation. Transfer the solution diluted in S130 to a 1L volumetric flask and fix the volume with the dilution solution prepared in S110, then the standard substance of aspartame solution in water with a standard value of (10 - 1000) μg / mL can be obtained. Refrigerate it under the condition of 0 - 4°C.

[0039] Example 1. Standard substance of aspartame solution in water with a standard value of 1000 μg / mL

[0040] This example provides a preparation method of a standard substance of aspartame solution in water with a standard value of 1000 μg / mL, including the following steps:

[0041] (1) Accurately weigh 31.3 g of citric acid, 15 g of sodium citrate and 10 g of ascorbic acid, dissolve them in an appropriate amount of pure water, transfer to a 2L volumetric flask, and fix the volume with pure water to obtain a dilution solution with the final concentrations of citric acid, sodium citrate and ascorbic acid being 15.65 g / L, 7.5 g / L, 5 g / L respectively, and the pH value being 3.6.

[0042] (2) Accurately weigh 1.00000 g of aspartame with a purity converted to 100% mass, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer to a 1L volumetric flask, and fix the volume with the dilution solution prepared in step (1) to obtain a standard substance of aspartame solution in water with a standard value of 1000 μg / mL. Refrigerate it under the condition of 0 - 4°C.

[0043] Example 2. Standard substance of aspartame solution in water with a standard value of 100 μg / mL

[0044] This example provides a preparation method of a standard substance of aspartame solution in water with a standard value of 100 μg / mL, including the following steps:

[0045] (1) Accurately weigh 27.52 g of citric acid, 20.28 g of sodium citrate and 4 g of ascorbic acid, dissolve them in an appropriate amount of pure water, transfer to a 2L volumetric flask, and fix the volume with pure water to obtain a dilution solution with the final concentrations of citric acid, sodium citrate and ascorbic acid being 13.76 g / L, 10.14 g / L, 2 g / L respectively, and the pH value being 4.0.

[0046] (2) Accurately weigh 0.10000 g of aspartame with a purity converted to 100% mass, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer to a 1L volumetric flask, and fix the volume with the dilution solution prepared in step (1) to obtain a standard substance of aspartame solution in water with a standard value of 100 μg / mL. Refrigerate it under the condition of 0 - 4°C.

[0047] Example 3 Standard Substance of Aspartame Solution in Water with a Standard Value of 10.0 μg / mL

[0048] This example provides a method for preparing a standard substance of aspartame solution in water with a standard value of 10.0 μg / mL, including the following steps:

[0049] (1) Accurately weigh 21.64 g of citric acid, 28.52 g of sodium citrate, and 2 g of ascorbic acid, dissolve them in an appropriate amount of pure water, transfer to a 2 L volumetric flask, and make up the volume with pure water to obtain a dilution solution with final concentrations of citric acid, sodium citrate, and ascorbic acid of 10.82 g / L, 14.26 g / L, and 1 g / L respectively, and a pH value of 4.6.

[0050] (2) Accurately weigh 0.01000 g of aspartame with a purity converted to 100% mass, add an appropriate amount of the dilution solution prepared in step (1) to dissolve, transfer to a 1 L volumetric flask, and make up the volume with the dilution solution prepared in step (1) to obtain a standard substance of aspartame solution in water with a standard value of 10.0 μg / mL. Store it refrigerated at 0 - 4°C.

[0051] Comparative Example 1 Standard Substance of Aspartame Solution in Water with a Standard Value of 1000 μg / mL

[0052] This comparative example provides a method for preparing a standard substance of aspartame solution in water with a standard value of 1000 μg / mL, including the following steps:

[0053] Accurately weigh 1.00000 g of aspartame with a purity converted to 100% mass, add an appropriate amount of pure water to dissolve, transfer to a 1 L volumetric flask, and make up the volume with pure water to obtain a standard substance of aspartame solution in water with a standard value of 1000 μg / mL. Store it refrigerated at 0 - 4°C.

[0054] Comparative Example 2 Standard Substance of Aspartame Solution in Water with a Standard Value of 1000 μg / mL

[0055] This comparative example provides a method for preparing a standard substance of aspartame solution in water with a standard value of 1000 μg / mL, including the following steps:

[0056] (1) Accurately weigh 0.1 g of sodium acetate trihydrate, 30 g of acetic acid, and 10 g of ascorbic acid, dissolve them in an appropriate amount of pure water, transfer to a 2 L volumetric flask, and make up the volume with pure water to obtain a dilution solution with final concentrations of sodium acetate trihydrate, acetic acid, and ascorbic acid of 0.05 g / L, 15 g / L, and 5 g / L respectively, and a pH value of 3.6.

[0057] (2)Accurately weigh 1.00000 g of aspartame converted to 100% mass according to purity, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer it to a 1 L volumetric flask, and make up the volume with the dilution solution prepared in step (1) to obtain an aspartame solution reference material in water with a standard value of 1000 μg / mL. Refrigerate it under the condition of 0 - 4°C.

[0058] Comparative Example 3 Aspartame solution reference material in water with a standard value of 1000 μg / mL

[0059] This comparative example provides a preparation method for an aspartame solution reference material in water with a standard value of 1000 μg / mL, including the following steps:

[0060] (1)Accurately weigh 31.3 g of citric acid, 15 g of sodium citrate, and 10 g of tea polyphenols, dissolve them in an appropriate amount of pure water, transfer them to a 2 L volumetric flask, and make up the volume with pure water to obtain a dilution solution with the final concentrations of citric acid, sodium citrate, and tea polyphenols being 15.65 g / L, 7.5 g / L, and 5 g / L respectively, and a pH value of 3.6.

[0061] (2)Accurately weigh 1.00000 g of aspartame converted to 100% mass according to purity, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer it to a 1 L volumetric flask, and make up the volume with the dilution solution prepared in step (1) to obtain an aspartame solution reference material in water with a standard value of 1000 μg / mL. Refrigerate it under the condition of 0 - 4°C.

[0062] Test Example 1

[0063] Taking the aspartame solution reference material in water with a standard value of 1000 μg / mL prepared in Example 1 as an example, this test example describes the method for establishing a standard curve. Dilute the aspartame solution in water with a standard value of 1000 μg / mL prepared in Example 1 with the dilution solution prepared in step (1) of Example 1 to obtain a series of standard working solutions with concentrations of 0 μg / mL, 50 μg / mL, 100 μg / mL, 200 μg / mL, 500 μg / mL, and 1000 μg / mL respectively.

[0064] Test the above series of standard working solutions by high performance liquid chromatography. Among them, the high performance liquid chromatography conditions are as follows:

[0065] Mobile phase: The volume ratio of methanol to water is 40:60;

[0066] Chromatographic column: C18, 250 mm × 4.6 mm × 5 μm;

[0067] Detection wavelength: 200 nm;

[0068] Column temperature: 30°C;

[0069] Flow rate: 0.8 mL / min;

[0070] Sample injection volume: 20 μl.

[0071] Using the concentration of the standard working solution as the abscissa and the peak area as the ordinate, a linear regression was performed to obtain the regression equation y = 250.1588x - 23.9613, R 2 > 0.9999. The standard curve graph is shown in Figure 2 .

[0072] Test Example 2

[0073] According to the high performance liquid chromatography conditions in Test Example 1 and the established standard curve, the stability of the aspartame solution reference material in water prepared in Examples 1-3 and Comparative Examples 1-3 was tested. The test results are shown in Table 1 and Figure 3 .

[0074]

[0075] The results showed that the aspartame solution reference material in water provided in Examples 1-3 of the present invention had no unidirectional trend change in quantity value under the refrigerated storage conditions, and the stability could reach 18 months; while the quantity value of the aspartame solution reference material in water in Comparative Examples 1-3 decreased and the stability was poor.

[0076] Test Example 3

[0077] According to the high performance liquid chromatography conditions in Test Example 1 and the established standard curve, the quantity value verification of the aspartame solution reference material in water prepared in Example 1 and the commercially available aspartame solution reference material was carried out. The relative standard deviation was 0.102%, which proved that the aspartame solution reference material in water provided by the present invention had good accuracy and reliable quantity value.

[0078] Although the present invention has been described in detail above with general descriptions and specific examples, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A method for preparing a standard substance of aspartame solution in water, characterized in that: The method comprises: Accurately weigh the aspartame standard, add the diluent to dissolve it, transfer it to a volumetric flask, and use the diluent to make up to (10-1000) μg / mL aspartame solution standard substance in water, wherein the diluent contains citric acid with a mass concentration of (10.82-15.65) g / L, sodium citrate with a mass concentration of (7.5-14.26) g / L, and ascorbic acid with a mass concentration of (1-5) g / L.

2. The method for preparing a standard substance of aspartame solution in water according to claim 1, characterized in that: The pH value of the dilution solution is 3.6-4.

6.

3. The method for preparing a standard substance of aspartame solution in water according to claim 1, characterized in that: The preparation method of the diluent is as follows: dissolving citric acid, sodium citrate and ascorbic acid in pure water to obtain solutions with final concentrations of citric acid, sodium citrate and ascorbic acid of (10.82-15.65) g / L, (7.51-14.26) g / L and (1-5) g / L, respectively.

4. The method for preparing a standard substance of aspartame solution in water according to claim 1, characterized in that: The purity of the aspartame standard is 98% to 100%.

5. A standard substance of aspartame solution in water, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 4.

6. The use of the aspartame solution in water standard substance according to claim 5, characterized in that: Used to detect the content of aspartame in food.

7. The use according to claim 6, characterized in that: Liquid chromatography-ultraviolet detector was used for detection. The conditions of liquid chromatography-ultraviolet detection included: Mobile phase: methanol and water in a volume ratio of 40:60; Chromatographic column: C18, 250 mm × 4.6 mm × 5 μm; Detection wavelength: 200nm; Column temperature: 30°C; Flow rate: 0.8 mL / min; Injection volume: 20μl.

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