A thiol foliar control agent for reducing mercury content in rice, and its preparation method and application

Abstract

The present invention relates to the technical field of leaf barrier control agents, and more specifically, to a mercapto leaf barrier control agent for reducing the mercury content in rice, as well as a preparation method and application. The raw materials of the mercapto leaf barrier control agent include γ-mercaptopropyltrimethoxysilane, solvent, water, citric acid, sodium selenate, sodium silicate and Tween 20. The γ-mercaptopropyltrimethoxysilane and sodium selenate in the raw materials of the present invention restrict the entry of atmospheric mercury into rice leaves through stomata and the migration from leaves to grains through efficient complexation, effectively reducing the total mercury content in rice, with relatively low repair costs and convenient large-scale promotion and application. In addition, the silicon element in the raw materials of the present invention can improve the yield and quality of rice to a certain extent, promote rice growth, and improve its stress resistance. Therefore, the mercapto leaf barrier control agent prepared by the present invention is evenly sprayed on the surface of rice leaves during the heading period, which can increase rice yield.

Description

Technical Field

[0001] The present invention relates to the technical field of foliar barrier control agents, and more specifically to a mercapto foliar barrier control agent for reducing the mercury content in rice, and a preparation method and application thereof. Background Art

[0002] Mercury is a highly toxic heavy metal and a non-essential element for the human body. It can exist in nature in various physical and chemical forms. Mercury and its compounds that enter the human body through different exposure pathways can cause multi-system health damage, mainly to the immune system, nervous system and kidneys. Rice is affected by a variety of factors, including the natural environment, industrial pollution, agricultural activities and social economy. The mercury content in paddy field soil and rice exceeds the standard, posing a serious threat to health.

[0003] At present, there are many methods for controlling the accumulation of mercury in rice at home and abroad. Common technologies mainly include agronomic control measures and the application of soil passivators, which can reduce the transfer of heavy metal mercury from the soil to the edible parts of crops and play a vital role in the safe production of crops. However, the cost of governance is relatively high, and it is difficult to promote and apply it on a large scale. Studies have shown that a considerable part of the mercury in rice grains is absorbed by the leaves from the atmosphere. The use of foliar control agents can inhibit the entry of atmospheric mercury through stomata or limit the migration of mercury from rice leaves to grains, thereby reducing the total mercury accumulation in rice. It has the advantages of easy operation, relatively low cost, and not easy to cause secondary soil pollution. However, there is currently a lack of foliar control agents on the market that can effectively reduce the mercury content in rice. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one aspect of the present invention is to provide a mercapto foliar barrier for reducing the mercury content in rice. The raw materials of the mercapto foliar barrier include γ-mercaptopropyltrimethoxysilane, solvent, water, citric acid, sodium selenate, sodium silicate, and Tween 20.

[0005] Preferably, the raw materials are recorded by weight as 5-25 parts of γ-mercaptopropyltrimethoxysilane, 100-200 parts of solvent, 241-387 parts of water, 2-4 parts of citric acid, 2-4 parts of sodium selenate, 2-4 parts of sodium silicate and 2-4 parts of Tween 20.

[0006] Preferably, the solvent is 75% ethanol solution, and the water is deionized water.

[0007] Another aspect of the present invention is to provide a method for preparing a thiol foliar barrier agent for reducing the mercury content in rice. The specific steps of the preparation method are as follows:

[0008] S1. Use a pipette to accurately measure γ-mercaptopropyltrimethoxysilane (3-MPTS) and dissolve it in a solvent to obtain solution I;

[0009] S2. Add dehydrate, citric acid, sodium selenate, sodium silicate and Tween 20 to solution I in S1, and stir to obtain solution II;

[0010] S3. Add sub-water to solution II in S2, adjust the pH value with acid and / or alkaline solution, and fix the volume to obtain the thiol foliar barrier agent.

[0011] Preferably, the mass ratio of the γ-mercaptopropyltrimethoxysilane, solvent, water, citric acid, sodium selenate, sodium silicate and Tween 20 is 5-25:100-200:241-387:2-4:2-4:2-4:2-4.

[0012] Preferably, the solvent is 75% ethanol solution, and the water is deionized water.

[0013] Preferably, the acid in S3 is dilute nitric acid and the base is sodium hydroxide.

[0014] Preferably, the pH in S3 is adjusted to 7.5-8.5.

[0015] Preferably, since the thiol foliar barrier agent contains easily oxidizable thiol groups, it is stored in vacuum packaging.

[0016] Another aspect of the present invention is to provide an application of a mercapto foliar barrier agent for reducing the mercury content in rice, wherein the application is sprayed on the rice leaves during the heading period of rice, and / or additionally sprayed once during the filling period at a half-dosage; 50 mL of the foliar barrier agent is dissolved in 20 L of water, and the spraying amount is 250 mL / mu-1000 mL / mu (content of the mercapto foliar barrier agent).

[0017] The beneficial effects of the present invention are as follows:

[0018] The γ-mercaptopropyltrimethoxysilane and sodium selenate in the raw materials of the present invention restrict the atmospheric mercury from entering the rice leaves through the stomata and migrating from the leaves to the grains through efficient complexation, effectively reducing the total mercury content of rice, with relatively low repair costs and convenient large-scale promotion and application. In addition, the silicon element in the raw materials of the present invention can improve the yield and quality of rice to a certain extent, promote the growth of rice, and improve its stress resistance. Therefore, the mercapto foliar barrier prepared by the present invention is evenly sprayed on the surface of rice leaves during the heading period, which can increase the rice yield.

[0019] Additional aspects and advantages of the invention will become apparent from the following description, or may be learned by practice of the invention. DETAILED DESCRIPTION

[0020] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0021] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from the description. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0022] Embodiment 1

[0023] S1. Use a pipette to accurately measure 5 mL of γ-mercaptopropyltrimethoxysilane (3-MPTS) and dissolve it in 100 mL of 75% ethanol solution to obtain solution I;

[0024] S2. Add 100 mL of deionized water, 2 g of citric acid, 2 g of sodium selenate, 2 g of sodium silicate and 2 g of Tween 20 to solution I in S1, and stir to obtain solution II;

[0025] S3. Add deionized water to solution II in S2, adjust the pH value to 7.5-8.5 with dilute nitric acid and / or sodium hydroxide solution, fix the volume to 500 mL, obtain the thiol foliar control agent, and vacuum package it.

[0026] Embodiment 2

[0027] S1. Use a pipette to accurately measure 15 mL of γ-mercaptopropyltrimethoxysilane (3-MPTS) and dissolve it in 100 mL of 75% ethanol solution to obtain solution I.

[0028] S2. Add 100 mL of deionized water, 2 g of citric acid, 4 g of sodium selenate, 2 g of sodium silicate and 4 g of Tween 20 to solution Ⅰ in S1, and stir to obtain solution Ⅱ;

[0029] S3. Add deionized water to solution II in S2, adjust the pH value to 7.5-8.5 with dilute nitric acid and / or sodium hydroxide solution, fix the volume to 500 mL, obtain the thiol foliar control agent, and vacuum package it.

[0030] Embodiment 3

[0031] S1. Use a pipette to accurately measure 10 mL of γ-mercaptopropyltrimethoxysilane (3-MPTS) and dissolve it in 100 mL of 75% ethanol solution to obtain solution I.

[0032] S2. Add 100 mL of deionized water, 4 g of citric acid, 2 g of sodium selenate, 4 g of sodium silicate and 2 g of Tween 20 to solution Ⅰ in S1, and stir to obtain solution Ⅱ;

[0033] S3. Add deionized water to solution II in S2, adjust the pH value to 7.5-8.5 with dilute nitric acid and / or sodium hydroxide solution, fix the volume to 500 mL, obtain the thiol foliar control agent, and vacuum package it.

[0034] 50 mL of the mercapto foliar barrier prepared in the embodiment of the present invention is dissolved in 20 L of water, and at the heading stage of rice, 250 mL / mu-1000 mL / mu (content of mercapto foliar barrier) is uniformly sprayed on the rice leaves using an unmanned aerial vehicle or a manual sprayer; or an additional spray is applied once at the filling stage at half the dosage.

[0035] The mercury content in the soil was 2.5 mg / kg, the pH value was 6.2, and the total mercury content in the rice after using the thiol foliar barrier agent of the present invention was as shown in Table 1 below.

[0036] Table 1. Reduction of mercury content in rice using this product

[0037]

[0038] From the above data, it can be seen that the mercury reduction rate of the mercapto foliar barrier prepared by the present invention is directly related to the dosage and the number of sprayings. When the dosage reaches 1000mL / mu or more, the mercury content in rice after one spraying is lower than the national limit standard of 20μg / kg; the effect of the second spraying is better than that of the first spraying, and the mercury content in rice can be reduced to 20μg / kg when the dosage reaches 500mL / mu or more. Therefore, the preferred application amount is 1000mL / mu for one spray or 500mL / mu for two sprays.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may also have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A thiol foliar control agent for reducing mercury content in rice, characterized in that: The raw materials of the mercapto foliar barrier agent include γ-mercaptopropyltrimethoxysilane, solvent, water, citric acid, sodium selenate, sodium silicate and Tween 20; The raw materials are recorded by weight as 5-25 parts of γ-mercaptopropyltrimethoxysilane, 100-200 parts of solvent, 241-387 parts of water, 2-4 parts of citric acid, 2-4 parts of sodium selenate, 2-4 parts of sodium silicate and 2-4 parts of Tween 20; The solvent is 75% ethanol solution, and the water is deionized water.

2. The method for preparing a thiol foliar barrier agent for reducing mercury content in rice according to claim 1, characterized in that: The specific steps of the preparation method are as follows: S1. Use a pipette to accurately measure γ-mercaptopropyltrimethoxysilane and dissolve it in a solvent to obtain solution I; S2. Add water, citric acid, sodium selenate, sodium silicate and Tween 20 to solution I in S1, and stir to obtain solution II; S3. Add water to solution II in S2, adjust the pH value with acid and / or alkaline solution, and fix the volume to obtain a thiol foliar barrier agent.

3. The method for preparing a thiol foliar barrier agent for reducing mercury content in rice according to claim 2, characterized in that: The mass ratio of the gamma-mercaptopropyltrimethoxysilane, solvent, water, citric acid, sodium selenate, sodium silicate and Tween 20 is 5-25:100-200:241-387:2-4:2-4:2-4:2-4.

4. The method for preparing a mercapto foliar barrier agent for reducing mercury content in rice according to claim 2, characterized in that: The solvent is 75% ethanol solution, and the water is deionized water.

5. The method for preparing a thiol foliar barrier agent for reducing mercury content in rice according to claim 2, characterized in that: The acid in S3 is dilute nitric acid, and the alkali is sodium hydroxide.

6. The method for preparing a thiol foliar barrier agent for reducing mercury content in rice according to claim 2, characterized in that: The pH in S3 is adjusted to 7.5-8.

5.

7. The method for preparing a mercapto foliar barrier agent for reducing mercury content in rice according to claim 2, characterized in that: The thiol foliar barrier control agent is stored in vacuum packaging.

8. The use of a thiol foliar barrier agent for reducing mercury content in rice according to claim 1, characterized in that: The application is to spray the rice leaves during the heading period, and / or spray once more during the filling period at a half-dose; 50 mL of the foliar inhibitor is dissolved in 20 L of water, and the spraying amount is 250 mL / mu-1000 mL / mu.

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