Method for screening montmorillonite with high aflatoxin adsorption rate and method for treating aflatoxin-contaminated samples

Abstract

The present invention relates to the field of aflatoxin treatment, and in particular to a method for screening montmorillonite with a high aflatoxin adsorption rate and a method for treating aflatoxin-contaminated samples. The method for screening montmorillonite with a high aflatoxin adsorption rate comprises: taking a plurality of montmorillonite samples to be screened, performing X-ray diffraction on each of them, and obtaining XRD patterns of the plurality of montmorillonite samples to be screened; analyzing the peak area S corresponding to the characteristic peak of 2θ of 26-27.5° in each XRD pattern, and the montmorillonite sample with a larger S is a montmorillonite with a higher aflatoxin adsorption rate among the plurality of montmorillonites to be screened. The above method is simple to operate, saves time, has low cost, is environmentally friendly, and can accurately determine whether the montmorillonite has a high aflatoxin adsorption capacity.

Description

Technical Field

[0001] The present invention relates to the field of aflatoxin treatment, and in particular to a method for screening montmorillonite with a high aflatoxin adsorption rate and a method for treating aflatoxin-contaminated samples. Background Art

[0002] Montmorillonite has the ability to adsorb aflatoxins (AFT). Currently, the EU has approved montmorillonite as an animal feed additive. Montmorillonite's adsorption capacity for aflatoxins, particularly aflatoxin B1, is an important indicator for evaluating the quality of montmorillonite products.

[0003] At present, the method for judging whether montmorillonite has a good ability to adsorb aflatoxins is generally as follows: first detect the aflatoxin content in the sample before treatment with montmorillonite, then detect the aflatoxin content in the sample after treatment with montmorillonite, so as to judge whether montmorillonite has a good ability to adsorb aflatoxins.

[0004] Currently, the main methods for detecting aflatoxins include thin-layer chromatography (TLC), enzyme-linked immunosorbent assay (ELISA), colloidal gold immunochromatography (GICA), fluorescence spectrophotometry, high-performance liquid chromatography (HPLC), ultra-high-pressure liquid chromatography (UPLC), and ultra-high-pressure liquid chromatography-tandem mass spectrometry. Among them, thin-layer chromatography is cumbersome to operate and difficult to master, so it is generally difficult to obtain satisfactory reproducibility and sensitivity. In addition, thin-layer chromatography requires a large number of organic solvents such as benzene and chloroform, which are also prone to environmental pollution and are gradually being replaced by other methods. The enzyme-linked immunosorbent assay is suitable for samples with relatively simple matrices, but is prone to false positives. The colloidal gold immunochromatography assay can complete semi-quantitative analysis of samples in a short period of time and determine the positive or negative nature of the sample, but accurate quantification still requires the use of other methods such as high-performance liquid chromatography. Ultra-high-pressure liquid chromatography-tandem mass spectrometry has a low detection limit and accurate results, but the equipment investment cost is relatively high. The investment in high-performance liquid chromatography equipment is relatively low, and most laboratories are currently equipped with it. The determination of AFT using high-performance liquid chromatography has the advantages of high accuracy and reliable results. It is currently the main method for detecting aflatoxins. However, this method also requires the testing personnel to have a high level of pre-processing capabilities, and the pre-processing requires a large amount of time and consumables costs.

[0005] Therefore, there is an urgent need to develop a method that is simple to operate, saves time, is low in cost, is environmentally friendly, and can accurately determine whether montmorillonite has a high aflatoxin adsorption capacity. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned problems existing in the prior art and provide a method for screening montmorillonite with a high aflatoxin adsorption rate and a method for treating aflatoxin. The above method is simple to operate, saves time, has low cost, and can accurately determine whether the montmorillonite has a high aflatoxin adsorption capacity.

[0007] The inventors of the present invention have found in their research that the area of the characteristic peak with a 2θ value of 26-27° in the XRD pattern of montmorillonite is positively correlated with the adsorption rate of aflatoxins (especially aflatoxin B1). Therefore, in order to achieve the above-mentioned purpose, the first aspect of the present invention provides a method for screening montmorillonite with a high aflatoxin adsorption rate, the method comprising: taking a plurality of montmorillonite samples to be screened, performing X-ray diffraction on each of them, and obtaining XRD patterns of the plurality of montmorillonite samples to be screened; analyzing the peak area S corresponding to the characteristic peak with a 2θ value of 26-27.5° in each XRD pattern, the montmorillonite sample with a larger S has a higher aflatoxin adsorption rate among the plurality of montmorillonite samples to be screened.

[0008] A second aspect of the present invention provides a method for treating a sample contaminated with aflatoxin, the method comprising:

[0009] (1) Screening montmorillonite with a higher aflatoxin adsorption rate according to the above method;

[0010] (2) The montmorillonite screened in (1) is used to treat the sample to be deaflatoxined.

[0011] Through the above technical solution, the present invention can achieve the following beneficial effects:

[0012] 1. The technical solution provided by the present invention saves time, requires almost no consumables, is low in cost, is environmentally friendly, and is easy to operate.

[0013] 2. The technical solution provided by the present invention enables rapid and accurate screening of montmorillonite with a high aflatoxin adsorption rate without damaging or contaminating the sample. The screened montmorillonite can be used to treat aflatoxin with a high adsorption rate, achieving excellent treatment results. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is the XRD pattern of 2θ=25.6-27.7 obtained in Example 1;

[0015] Figure 2 This is the XRD pattern at 2θ=20-30° obtained in Example 1. DETAILED DESCRIPTION

[0016] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0017] In a first aspect, the present invention provides a method for screening montmorillonite with a high aflatoxin adsorption rate, the method comprising: taking multiple montmorillonite samples to be screened, performing X-ray diffraction on each of them, and obtaining XRD patterns of the multiple montmorillonite samples to be screened; analyzing the peak area S corresponding to the characteristic peak with 2θ of 26-27.5° in each XRD pattern, the montmorillonite sample with a larger S has a higher aflatoxin adsorption rate among the multiple montmorillonite samples to be screened.

[0018] Aflatoxins (AFTs) are bifuranoid toxins produced by certain strains of Aspergillus flavus and Aspergillus parasiticus. AFTs have approximately 20 derivatives, designated as B1, B2, G1, G2, M1, M2, GM, P1, Q1, and AFT. B1 is the most toxic and carcinogenic.

[0019] The method involves adding montmorillonite to a contaminated sample to adsorb aflatoxins. The ratio of the amount of aflatoxins adsorbed in the contaminated sample after adsorption to the amount before adsorption is referred to as the "adsorption rate." The inventors of the present invention have discovered that the peak area S corresponding to the characteristic peak at 26-27.5° in the XRD pattern of the montmorillonite sample being screened correlates with the aflatoxin adsorption rate of the montmorillonite sample being screened. A larger peak area S indicates a higher aflatoxin adsorption rate for the corresponding montmorillonite sample being screened.

[0020] According to the present invention, preferably, the aflatoxin is aflatoxin B1.

[0021] According to the present invention, in order to further ensure that the screening has a high accuracy, preferably, the X-ray diffraction conditions include: a step size of 0.08-0.13°, wherein the voltage can be 40 kV, the current can be 40 mA, and the 2θ range can be 15-30°.

[0022] According to the present invention, in order to further ensure that the screening has higher accuracy, preferably, 2θ=26.3-27.1°.

[0023] According to the present invention, preferably, the montmorillonite sample having the largest peak area S of the characteristic peak of the adsorption rate is the montmorillonite having the highest aflatoxin adsorption rate among the multiple montmorillonites to be screened.

[0024] A second aspect of the present invention provides a method for treating a sample contaminated with aflatoxin, the method comprising:

[0025] (1) Screening montmorillonite with a higher aflatoxin adsorption rate according to the above method;

[0026] (2) The montmorillonite screened in (1) is used to treat the sample to be deaflatoxined.

[0027] According to the present invention, in order to further ensure a high adsorption rate, preferably, the sample to be deaflatoxinized is food or animal feed contaminated with aflatoxins. The method provided by the present invention is particularly suitable for edible oils contaminated with aflatoxins, such as peanut oil, rapeseed oil, etc.

[0028] According to the present invention, in order to further ensure that a higher adsorption rate can be obtained, preferably, in step (2), relative to 100g of the sample to be deaflatoxinized, the amount of montmorillonite used is 0.05-1g (for example, it can be 0.05g, 0.1g, 0.2g, 0.3g, 0.4g, 0.5g, 0.6g, 0.7g, 0.8g, 0.9g, 1g and a value within the range formed by any two of the above values).

[0029] According to the present invention, in order to further ensure that a higher adsorption rate can be obtained, preferably, the treatment method further comprises: mixing and stirring the montmorillonite and the sample to be deaflatoxinized.

[0030] According to the present invention, in order to further ensure that a higher adsorption rate can be obtained, preferably, the treatment conditions include: a temperature of 100-130°C (for example, it can be 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C and a value within the range formed by any two of the above values), a time of 0.5-2h (for example, it can be 0.5h, 1h, 1.5h, 2h and a value within the range formed by any two of the above values), and a rotation speed of 200-500r / min (for example, it can be 200r / min, 250r / min, 300r / min, 350r / min, 400r / min, 450r / min, 500r / min). It can be understood that under such conditions, montmorillonite and the sample to be deaflatoxinized can be more fully mixed and stirred, which can make the mixed material more uniform, thereby helping to further improve the adsorption rate.

[0031] According to a particularly preferred embodiment of the present invention, montmorillonite with a high aflatoxin adsorption rate is screened and aflatoxin-contaminated samples are treated according to the following method:

[0032] (1) Taking multiple montmorillonite samples to be screened, performing X-ray diffraction on each of them, and analyzing the peak area S corresponding to the characteristic peak with 2θ of 26.3-27.1° in each XRD spectrum obtained. The montmorillonite sample with the largest S is the montmorillonite with the highest aflatoxin adsorption rate among the multiple montmorillonites to be screened.

[0033] (2) Adding the montmorillonite screened in (1) to aflatoxin-contaminated food or animal feed, wherein the amount of the montmorillonite is 0.1-0.3 g relative to 100 g of the aflatoxin-contaminated food or animal feed. Mixing and stirring the mixture at 112-117° C. and 320-370 r / min for 0.9-1.3 h to obtain treated food or animal feed.

[0034] The present invention will be described in detail below through examples. In the following examples, the aflatoxin content of the food or animal feed contaminated with aflatoxin was determined by high performance liquid chromatography before being treated with montmorillonite.

[0035] Example 1

[0036] Used to illustrate the method for screening montmorillonite with high aflatoxin adsorption rate provided by the present invention

[0037] Three different types of montmorillonite from the same manufacturer were taken and recorded as ordinary montmorillonite A, modified montmorillonite B and high-purity montmorillonite C respectively.

[0038] Take the above-mentioned ordinary montmorillonite A, modified montmorillonite B, and high-purity montmorillonite C, and perform X-ray diffraction under the conditions of voltage 40kV, current 40mA, 2θ range 20-30°, and step size 0.115° to obtain their XRD patterns respectively. Place the three obtained XRD patterns in the same coordinate system, such as Figure 1 (Will Figure 2 The part with 2θ=25.6-27.7 is enlarged) and Figure 2 As shown, their characteristic peaks at 2θ = 26.3-27.1° were found and the peak areas of the characteristic peaks were compared to obtain the peak areas: high-purity montmorillonite C > modified montmorillonite B > ordinary montmorillonite A. There was no obvious difference in the peak areas of the characteristic peaks at 2θ = 19.0-20.5° among the three samples.

[0039] Example 2

[0040] Used to illustrate the method for screening montmorillonite with high aflatoxin adsorption rate provided by the present invention

[0041] Montmorillonite samples from three different manufacturers, designated montmorillonite D, montmorillonite E, and montmorillonite F, were subjected to X-ray diffraction at 40 kV, 40 mA, and a 2θ range of 20-30° with a step size of 0.115° to obtain their XRD patterns. The three XRD patterns were aligned in the same coordinate system, and their characteristic peaks at 2θ = 26.3-27.1° were found. The order of peak area was: montmorillonite E > montmorillonite D > montmorillonite F. The peak areas of the characteristic peak at 2θ = 19.0-20.5° were not significantly different among the three samples.

[0042] Test Example 1

[0043] 100 g of peanut oil contaminated with aflatoxin B1 was added with 0.2 g of ordinary montmorillonite A from Example 1. The mixture was then stirred at 115°C and 350 rpm for 1 hour. The mixture was then centrifuged at 6500 rpm for 10 minutes to remove the montmorillonite, yielding treated peanut oil.

[0044] The aflatoxin-contaminated samples were treated according to the above method, except that 0.2 g of modified montmorillonite B in Example 1, 0.2 g of high-purity montmorillonite C in Example 1, 0.2 g of montmorillonite D in Example 2, 0.2 g of montmorillonite E in Example 2, and 0.2 g of montmorillonite F in Example 2 were used respectively.

[0045] After the treatment, the aflatoxin content in the treated peanut oil or animal feed was determined using high performance liquid chromatography, and the aflatoxin adsorption rates of the different montmorillonites were calculated. The results are shown in Table 1.

[0046] The adsorption rate is calculated as follows: first determine the content of aflatoxin B1 C0 in peanut oil that has not been treated with montmorillonite, then determine the content of aflatoxin B1 C1 in the treated peanut oil after treatment with montmorillonite, and 100%*(C0-C1) / C0 is the adsorption rate. The method for determining the content of aflatoxin in peanut oil is the third method of high performance liquid chromatography post-column derivatization (photochemical derivatization) in GB 5009.22-2016.

[0047] Table 1

[0048] Example No. Adsorption rate (%) Ordinary Montmorillonite A 73.1 Modified montmorillonite B 95.0 High purity montmorillonite C 98.2 Montmorillonite D 55 Montmorillonite E 91.6 Montmorillonite F 53.4

[0049] Test Example 2

[0050] Aflatoxins were removed according to the method in Test Example 1, except that the peanut oil contaminated with aflatoxin B1 in Test Example 1 was replaced with rapeseed oil contaminated with aflatoxin B1. The results are shown in Table 2.

[0051] Table 2

[0052]

[0053]

[0054] The results in Table 1 show that the order of aflatoxin adsorption rates for the three montmorillonites in Example 1 is: high-purity montmorillonite C > modified montmorillonite B > ordinary montmorillonite A. This order is consistent with the peak area of the characteristic peak at 2θ = 26.3-27.1°, and differs from the order of the peak area corresponding to the characteristic peak at 2θ = 19.0-20.5°. This indicates that the peak area of the characteristic peak at 2θ = 26.3-27.0° is indeed related to the aflatoxin adsorption rate of the montmorillonite. Therefore, the method provided by the present invention for screening montmorillonites with high aflatoxin adsorption rates can accurately determine whether a montmorillonite has a high aflatoxin adsorption capacity. The same conclusion can be drawn from the results of montmorillonite D, montmorillonite E, and montmorillonite F. The same conclusion can be drawn from Table 2. Furthermore, the method of the present invention is simple to operate, saves time, requires almost no consumables, is low in cost, and is environmentally friendly.

[0055] In addition, it can be seen from the results in Table 1-2 that the method for treating aflatoxin provided by the present invention can adsorb aflatoxin in the sample to be deaflatoxinized with a relatively high adsorption rate.

[0056] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for screening montmorillonite with high aflatoxin adsorption rate, characterized in that: The method comprises: taking a plurality of montmorillonite samples to be screened, performing X-ray diffraction on each of the samples, and obtaining XRD patterns of the plurality of montmorillonite samples to be screened; and analyzing the peak area S corresponding to a characteristic peak with a 2θ value of 26-27.5° in each XRD pattern, wherein a montmorillonite sample with a larger S has a higher aflatoxin adsorption rate among the plurality of montmorillonite samples to be screened.

2. The method according to claim 1, wherein The aflatoxin is aflatoxin B1.

3. The method according to claim 1 or 2, wherein: The X-ray diffraction conditions include: a step size of 0.08-0.13°.

4. The method according to any one of claims 1 to 3, wherein: 2θ=26.3-27.1°.

5. The method according to any one of claims 1 to 4, wherein: The montmorillonite sample having the largest peak area S of the characteristic peak of the adsorption rate is the montmorillonite having the highest aflatoxin adsorption rate among the multiple montmorillonites to be screened.

6. A method for treating aflatoxin-contaminated samples, characterized in that: The method includes: (1) Screening montmorillonite with a high aflatoxin adsorption rate according to the method described in any one of claims 1 to 5; (2) The montmorillonite screened in (1) is used to treat the sample to be deaflatoxined.

7. The method according to claim 6, wherein: The sample to be deaflatoxined is food or animal feed contaminated with aflatoxin.

8. The method according to claim 6 or 7, wherein: In step (2), the amount of montmorillonite used is 0.05-1 g relative to 100 g of the sample to be deaflatoxinized.

9. The method according to any one of claims 6 to 8, wherein: In step (2), the treatment method further comprises: mixing and stirring the montmorillonite and the sample to be deaflatoxinized.

10. The method according to claim 9, wherein: The treatment conditions include: temperature of 100-130° C., time of 0.5-2 h, and rotation speed of 200-500 r / min.

Images