Novel food additive analysis method based on chromatographic food quality detection

Abstract

The invention discloses a novel food additive analysis method based on chromatographic food quality detection in the technical field of food detection methods, and the novel food additive analysis method comprises the following steps: adding water into food to be detected, carrying out ultrasonic extraction to obtain a mixed solution, and then adding a potassium ferrocyanide solution and a zinc acetate solution into the mixed solution to obtain a supernatant; adding a hydrochloric acid solution into one part of supernate to obtain a first intermediate solution, carrying out ultrasonic degassing on the first intermediate solution, adding normal hexane into the first intermediate solution, and oscillating to obtain a first extracting solution of a middle stage; taking the other part of supernate, adding a derivatization reagent to obtain a second intermediate solution, and adding normal hexane and a sodium chloride solution to obtain a second extracting solution; mixing the first extracting solution and the second extracting solution to obtain a to-be-detected solution; a chromatograph-mass spectrometer is used for detecting a to-be-detected solution and a standard solution, so that the problem that the experiment efficiency is easily influenced due to the fact that a precipitant used in the prior art is relatively slow in precipitation speed is solved to a certain extent.

Description

Technical Field

[0001] The present invention belongs to the technical field of food detection methods, and in particular is a novel food additive analysis method based on chromatographic food quality detection. Background Art

[0002] The modern food industry is developing rapidly, and additives such as sweeteners, preservatives, and thickeners are widely used in food processing. Although most companies limit their use in accordance with the provisions of GB2760, there are still some problems such as out-of-scope use and excessive use.

[0003] Chromatographic analysis is commonly used in the prior art to determine the content of food additives in food samples. When preparing the test solution used for chromatographic analysis, ultrasound is used to cause the test components in the food sample to overflow into the aqueous solution, and then the aqueous solution is precipitated to remove impurities. However, the precipitant commonly used in the prior art, such as sodium tungstate solution and sulfuric acid solution, has a slow precipitation rate, which can easily affect experimental efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a novel food additive analysis method based on chromatographic food quality detection, which is used to solve the problem that the precipitant used in the prior art has a slow precipitation rate and is likely to affect the experimental efficiency to a certain extent.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows: a new food additive analysis method based on chromatographic food quality detection, comprising

[0006] Step 1: Add water to the food to be tested, mix well, and then perform ultrasonic extraction to obtain a mixed solution. Then, add potassium ferrocyanide solution and zinc acetate solution to the mixed solution, shake and centrifuge, and remove the upper clear liquid at different positions of the centrifuged mixed solution to obtain the supernatant;

[0007] Step 2: Divide the supernatant into two portions, add hydrochloric acid solution to either portion of the supernatant to obtain a first intermediate solution, ultrasonically degas the first intermediate solution, add n-hexane to the first intermediate solution and shake it, then let it stand until the first intermediate solution separates, drain the upper supernatant of the first intermediate solution, and discard the upper portion of the liquid to obtain the first extract of the middle portion;

[0008] Step 3: Add a derivatization reagent to another portion of the supernatant to obtain a second intermediate solution, place the second intermediate solution in an ice bath, and add n-hexane and sodium chloride solution. Then, the second intermediate solution is allowed to stand at room temperature until layers form in the second intermediate solution. The upper supernatant of the second intermediate solution is collected to obtain a second extract.

[0009] Step 4: Mixing the first extract and the second extract to obtain a test solution;

[0010] Step 5: Take cyclamate and sorbic acid standard substances, dissolve and adjust to volume to obtain a standard solution;

[0011] Step 6: Use a chromatogram-mass spectrometer to detect the test solution and the standard solution, obtain the peak graphs of the chromatogram and mass spectrum of the test solution and the standard solution, and compare the peak graphs of the chromatogram and mass spectrum of the test solution and the standard solution to obtain the content of saccharin and sorbic acid in the test solution.

[0012] Furthermore, the duration of the ice bath in step 3 is thirty minutes.

[0013] Furthermore, in step 5, the first extract and the second extract are mixed and filtered to obtain a test solution.

[0014] Furthermore, in step 1, the food to be tested is crushed before adding water to the food to be tested.

[0015] Furthermore, the duration of the ultrasonic extraction in step 1 is fifteen minutes.

[0016] Furthermore, in the process of centrifuging the mixed solution after adding the potassium ferrocyanide solution and the zinc acetate solution in step 1, the rotation speed is 6,000 rpm and the centrifugation time is 5 minutes.

[0017] Furthermore, in step 5, filtration is performed using a filter membrane with a pore size of 0.22 μm.

[0018] Furthermore, during the ice bath in step 3, the second intermediate solution is shaken every five minutes.

[0019] The technical principles and beneficial effects of the above scheme are as follows: This scheme improves precipitation efficiency and experimental efficiency by adding potassium ferrocyanide solution and zinc acetate solution, and at the same time crushes the food to be tested, sets appropriate ice bath time, ultrasonic extraction time and centrifugation time, etc., effectively derivatizes the reaction speed between the reagent and the supernatant, and further improves experimental efficiency. In this scheme, the operation of filtering after mixing the first extract and the second extract can, to a certain extent, avoid the impact of reaction precipitates in the first extract and the second extract on subsequent experiments. In this scheme, by stirring during the ice bath, the temperature of the second intermediate solution can be made more uniform, to a certain extent avoiding the uneven temperature of the second intermediate solution and the impact on the reaction, and to a certain extent solves the problem that the precipitant used in the prior art has a slow precipitation speed and is easy to affect the experimental efficiency.

[0020] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a flow chart of an embodiment of a novel food additive analysis method based on chromatographic food quality testing according to the present invention;

[0022] Figure 2 A cross-sectional view of an embodiment of a novel food additive analysis method based on chromatographic food quality testing according to the present invention;

[0023] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0024] The reference numerals in the drawings of the specification include: collecting tube 1, separation tube 2, reversing ball 21, waste liquid tube 3, branch tube 31, connecting tube 4, placement tube 5, second plate 6, first plate 7. DETAILED DESCRIPTION

[0025] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0026] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "vertical", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0027] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0028] The following is further described in detail through specific implementation methods:

[0029] Example 1

[0030] As attached Figure 1A novel food additive analysis method based on chromatographic food quality testing is shown, comprising: step 1: adding water to the food to be tested, mixing uniformly, and then performing ultrasonic extraction to obtain a mixed solution; then adding potassium ferrocyanide solution and zinc acetate solution to the mixed solution, shaking and centrifuging, and removing the upper clear liquid at different positions of the centrifuged mixed solution to obtain a supernatant;

[0031] Step 2: Divide the supernatant into two portions, add hydrochloric acid solution to either portion of the supernatant to obtain a first intermediate solution, ultrasonically degas the first intermediate solution, add n-hexane to the first intermediate solution and shake it, then let it stand until the first intermediate solution separates, drain the upper supernatant of the first intermediate solution, and discard the upper portion of the liquid to obtain the first extract of the middle portion;

[0032] Step 3: Add a derivatization reagent to another portion of the supernatant to obtain a second intermediate solution, place the second intermediate solution in an ice bath, and add n-hexane and sodium chloride solution. Then, the second intermediate solution is allowed to stand at room temperature until layers form in the second intermediate solution. The upper supernatant of the second intermediate solution is collected to obtain a second extract.

[0033] Step 4: Mixing the first extract and the second extract to obtain a test solution;

[0034] Step 5: Take cyclamate and sorbic acid standard substances, dissolve and adjust to volume to obtain a standard solution;

[0035] Step 6: Use a chromatogram-mass spectrometer to detect the test solution and the standard solution, obtain the peak graphs of the chromatogram and mass spectrum of the test solution and the standard solution, and compare the peak graphs of the chromatogram and mass spectrum of the test solution and the standard solution to obtain the content of saccharin and sorbic acid in the test solution.

[0036] In this embodiment, the duration of the ice bath in step 3 is thirty minutes.

[0037] In this embodiment, in step 5, the first extract and the second extract are mixed and then filtered to obtain the test solution.

[0038] In this embodiment, in step 1, the food to be tested is crushed before adding water to the food to be tested.

[0039] In this embodiment, the duration of ultrasonic extraction in step 1 is fifteen minutes.

[0040] In this embodiment, in step 1, during the centrifugation of the mixed solution after the potassium ferrocyanide solution and the zinc acetate solution are added, the rotation speed is 6,000 rpm and the centrifugation time is 5 minutes.

[0041] In this embodiment, a filter membrane with a pore size of 0.22 μm is used for filtration in step 5.

[0042] In this embodiment, the second intermediate solution is shaken once every five minutes during the ice bath in step 3.

[0043] The specific implementation process is as follows: in step 1, four equal portions of the mixed solution are taken and numbered A1, A2, A3 and A4 in sequence, and equal portions of potassium ferrocyanide solution-zinc acetate solution, sodium tungstate solution-sulfuric acid solution, potassium ferrocyanide solution-zinc acetate solution and ethanol are added to the four equal portions of the mixed solution in sequence, and the precipitation of the four mixed solutions is observed. Subsequently, the four mixed solutions are treated through the above steps to obtain corresponding chromatograms and mass spectrometry peaks;

[0044] The precipitation conditions of the four mixed solutions are shown in Table 1;

[0045] Table 1

[0046]

[0047] As shown in Table 1, the precipitation treatment of the mixed solution using potassium ferrocyanide solution-zinc acetate solution has the best effect and a fast precipitation speed, which can improve the experimental efficiency to a certain extent.

[0048] Example 2

[0049] As attached Figure 2-3 As shown, the difference from Example 1 is that, in order to further improve the efficiency of the experiment, a device is also disclosed, including a placement tube 5, in which a first plate 7 and a second plate 6 are arranged in sequence from top to bottom. The side walls of the first plate 7 and the second plate 6 are slidably matched with the inner side wall of the placement tube 5, the bottom wall of the second plate 6 is arranged at an angle, and the bottom wall of the second plate 6 and the inner bottom wall of the placement tube 5 form a placement chamber, a plurality of connecting tubes 4 made of elastic material are fixedly connected to the second plate 6, and the input ends of the connecting tubes 4 are connected to the placement chamber, the side walls of the connecting tubes 4 are slidably matched with the first plate 7, the other end of the connecting tube 4 is provided with a diversion tube, the output end of the connecting tube 4 is connected with the input end of the diversion tube, the output end of the diversion tube is provided with a collecting tube 1, the collecting tube 1 can be connected with the diversion tube, the side wall of the separation tube 2 is provided with a branch tube 31, the branch tube 31 can be connected with the separation tube 2, and a reversing ball 21 is hinged at the connection point, the input end of the branch tube 31 is connected with a water pump, and the output end of the water pump is connected with a waste liquid pipe 3.

[0050] The specific implementation process is as follows: in step 2, the first intermediate liquid is placed in the placement tube 5, and after ultrasonic degassing the first intermediate liquid, n-hexane is added to the first intermediate liquid, and then the second plate 6 and the first plate 7 are placed in the placement tube 5 in turn, so that the bottom wall of the second plate 6 contacts the liquid surface of the first intermediate liquid, and the connecting tube 4 is straightened and expanded by the first plate 7 and the second plate 6 under the action of the gravity of the second plate 6, and then the placement tube 5 is shaken to make the n-hexane and the first intermediate liquid mix evenly, and after standing until stratification occurs in the first intermediate liquid, the first plate 7 is pushed downward, and at the same time, the connecting tube 4 is pulled upward while keeping the position of the second plate 6 unchanged, so that the bottom wall of the first plate 7 and the top wall of the second plate 6 contact, and the part of the connecting tube 4 located between the first plate 7 and the second plate 6 remains vertical, and the placement tube 5 is shaken again to make the liquid surface of the first intermediate liquid shake, and the connecting tube 5 is located 4, the liquid level between the inner walls rises. Under the action of the liquid surface tension and the internal viscosity of the water molecules, the connecting tube 4 is deformed, the cross-sectional area of ​​the connecting tube 4 becomes narrower, and the first intermediate liquid in the connecting tube 4 exhibits a capillary phenomenon and moves upward along the connecting tube 4. When it reaches the top wall of the placement tube 5, the first intermediate liquid in the connecting tube 4 drives the connecting tube 4 to bend under the action of gravity, and flows through the separation tube 2 into the waste liquid tube 3 under the action of gravity, so that the waste liquid tube 3 is connected with the placement tube 5, and a siphon effect is gradually formed. At the same time, the first intermediate liquid continuously impacts the reversing ball 21. When the siphon effect is formed, the flow rate of the first intermediate liquid passing through the separation tube 2 becomes larger, and the first intermediate liquid impacts the reversing ball 21, causing it to rotate. The connection between the waste liquid tube 3 and the placement tube 5 is closed, and the connection between the collecting tube 1 and the placement tube 5 is opened, and the remaining liquid in the placement tube 5 enters the placement tube 5;

[0051] Compared with the prior art method of first adding n-hexane for oscillation and then performing ultrasonic degassing, the device, through the arrangement of the placement tube 5, the first plate 7, the second plate 6 and the connecting tube 4, can avoid the cavitation effect during the ultrasonic degassing process to a certain extent, causing the first intermediate liquid to be mixed, prolonging the subsequent static stratification time, and thus reducing the experimental efficiency;

[0052] At the same time, compared with the method of first performing ultrasonic degassing and then adding n-hexane for oscillation, the present device can reduce the contact area between the first intermediate liquid and the air during the oscillation process, thereby reducing the generation of bubbles in the first intermediate liquid during the oscillation process that may affect subsequent test results;

[0053] Since bubbles in liquid tend to gather on the liquid surface, some bubbles may remain in the initial liquid. The arrangement of the reversing ball 21 in this device allows the first intermediate liquid in the initial stage to enter the waste liquid pipe, and only the liquid in the middle section of the collection tube 1 is collected, thereby further reducing the impact of bubbles on subsequent detection results.

[0054] The mixed liquid after centrifugation can also be placed in the placement tube 5. The bottom wall of the second plate 6 arranged obliquely in this device can make the bottom end of the connecting tube 4 contact the mixed liquid at different heights in the placement chamber, thereby collecting the clear liquid on the top of the mixed liquid at different heights, increasing the uniformity of the collected supernatant. Compared with the method of collecting the clear liquid at different heights on the top of the mixed liquid in sequence and then mixing them, this device can realize the simultaneous extraction of the clear liquid on the top of the mixed liquid at different heights, effectively improving the experimental efficiency.

[0055] The above is only an embodiment of the present invention, and common knowledge such as the specific structure and / or characteristics of the scheme is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A novel food additive analysis method based on chromatographic food quality testing, characterized by: include Step 1: Add water to the food to be tested, mix well, and then perform ultrasonic extraction to obtain a mixed solution. Then, add potassium ferrocyanide solution and zinc acetate solution to the mixed solution, shake and centrifuge, and remove the upper clear liquid at different positions of the centrifuged mixed solution to obtain the supernatant; Step 2: Divide the supernatant into two portions, add hydrochloric acid solution to either portion of the supernatant to obtain a first intermediate solution, ultrasonically degas the first intermediate solution, add n-hexane to the first intermediate solution and shake it, then let it stand until the first intermediate solution separates, drain the upper supernatant of the first intermediate solution, and discard the upper portion of the liquid to obtain the first extract of the middle portion; Step 3: Add a derivatization reagent to another portion of the supernatant to obtain a second intermediate solution, place the second intermediate solution in an ice bath, and add n-hexane and sodium chloride solution. Then, the second intermediate solution is allowed to stand at room temperature until layers form in the second intermediate solution. The upper supernatant of the second intermediate solution is collected to obtain a second extract. Step 4: Mixing the first extract and the second extract to obtain a test solution; Step 5: Take cyclamate and sorbic acid standard substances, dissolve and adjust to volume to obtain a standard solution; Step 6: Use a chromatogram-mass spectrometer to detect the test solution and the standard solution, obtain the peak graphs of the chromatogram and mass spectrum of the test solution and the standard solution, and compare the peak graphs of the chromatogram and mass spectrum of the test solution and the standard solution to obtain the content of saccharin and sorbic acid in the test solution.

2. The novel food additive analysis method based on chromatographic food quality detection according to claim 1, characterized in that: The duration of the ice bath in step 3 is thirty minutes.

3. The novel food additive analysis method based on chromatographic food quality detection according to claim 2, characterized in that: In step 5, the first extract and the second extract are mixed and filtered to obtain a test solution.

4. The novel food additive analysis method based on chromatographic food quality detection according to claim 3, characterized in that: In step 1, the food to be tested is crushed before adding water to the food to be tested.

5. The novel food additive analysis method based on chromatographic food quality detection according to claim 4, characterized in that: The duration of the ultrasonic extraction in step 1 is fifteen minutes.

6. The novel food additive analysis method based on chromatographic food quality detection according to claim 5, characterized in that: In step 1, the mixed solution after adding the potassium ferrocyanide solution and the zinc acetate solution is centrifuged at a speed of 6,000 rpm and a centrifugation time of 5 minutes.

7. The novel food additive analysis method based on chromatographic food quality detection according to claim 6, characterized in that: In step 5, filtration was performed using a filter membrane with a pore size of 0.22 μm.

8. The novel food additive analysis method based on chromatographic food quality detection according to claim 7, characterized in that: During the ice bath in step 3, the second intermediate solution was shaken every five minutes.

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