CN102823783B - Method for degrading pesticide residues in ginseng oral liquid by irradiation - Google Patents

Abstract

A method for degrading pesticide residues in ginseng oral liquid by irradiation belongs to the technical field of degradation treatment of pesticide residues in Chinese herbal medicines. The method adopts high-energy electrons generated under the irradiation condition of an electron accelerator to treat the ginseng oral liquid containing various pesticides (six kinds of forbidden pesticides such as methidathion, dimethion, diazinon, vofenthion, imidacloprid, fenpropathrin and the like) so as to degrade the ginseng oral liquid. The energy of the electron accelerator used in the invention is 7.5MeV, and the electron irradiation dose is 2-15 kGy. After irradiation, the concentrations of the six pesticides are measured by using an ultra-high performance liquid chromatography-tandem mass spectrometer, and the degradation effect is determined. The method can efficiently, quickly and safely reduce or eliminate the six pesticide residues in the ginseng oral liquid, and the degradation rates of the six pesticides related to the method exceed 30% during 15kGy irradiation, so that the limit standards of European Union and other countries are reached. The invention provides a good idea for degrading pesticides in the ginseng oral liquid and has a wide development prospect.

Description

A method for degrading pesticide residues in ginseng oral liquid by irradiation

technical field

The invention belongs to the technical field of degradation treatment of pesticide residues in Chinese herbal medicines, and in particular relates to an electron beam irradiation method for degrading methapon, fenfofos, diazinon, thionon, imidacloprid, and cyanide in commercial products of ginseng oral liquid Irradiation degradation method of six banned and restricted pesticides including permethrin.

Background technique

my country is the birthplace of Chinese herbal medicine. After years of unremitting efforts, foreign countries have gradually affirmed the important position of Chinese herbal medicine in the field of medical and health care. However, the problem of pesticide residues in Chinese herbal medicines has become the main reason why the export of Chinese herbal medicines is blocked in my country, and it is the most difficult barrier to overcome this precious cultural heritage of our country to the world. At present, developed countries such as the European Union, the United States, and Japan have put forward very strict technical index requirements for the control of pesticide residue limit indicators in imported traditional Chinese medicine and health care products. For example, the fifth edition of the European Pharmacopoeia stipulates the limit indicators of 162 kinds of toxic and harmful substances. Traditional Chinese medicine imported from my country must comply with its pharmacopoeia before entering the European market. The limit standards for several organophosphorus pesticides are: diazinon 0.5mg/kg, tefenthion 0.05mg/kg, methapion 0.2mg/kg, and thionon 0.1mg/kg. As another example, Japan re-established the industry standards for pesticide residues in traditional Chinese medicine in 2006, which stipulated that the pesticide residue limits in Chinese herbal medicines and their preparations were: 0.2 mg/kg of methapon, 0.3 mg/kg of imidacloprid, and 0.3 mg/kg of fenpropathrin. 0.2mg/kg. However, the establishment of pesticide residue standards in Chinese herbal medicines in my country lags behind developed countries and regions. Therefore, it is necessary to find a technical method to effectively reduce pesticide residues in Chinese herbal medicine as soon as possible, so as to adapt to the increasingly stringent testing standards, which has far-reaching significance for our country to deal with the opportunities and challenges of international trade.

Agricultural workers have been committed to the research and exploration of pesticide residue degradation methods. Methods such as microbial degradation, ozone degradation, photocatalytic degradation, hydrogen peroxide degradation, and adsorption removal use the principles of physical adsorption or chemical reaction, respectively, and have different effects on different types of pesticides. certain degradation. my country's irradiation technology has made breakthroughs in genetic breeding, food preservation, industrial wastewater treatment, and disinfection of medical drugs. However, as a new technology to improve food safety, research on irradiation degradation is still in its infancy. Lin Yan etc. have proved that γ-ray irradiation at a dose of 10kGy can make the degradation rate of dichlorvos or triazophos remaining in dried bamboo shoots reach more than 35%. Wu Ling et al. also conducted a feasibility study on the irradiation degradation of pyrethroid pesticides in tea. , but the research on the radiation degradation of pesticides in Chinese herbal medicines has not retrieved relevant literature.

Ginseng is a kind of precious Chinese herbal medicine that is a special product of our country. Due to its extremely high medicinal value and health care efficacy, it occupies a large proportion of the Chinese herbal medicine market and the health care product market. Contaminated by pesticides, ginseng and its products all have pesticide residues. The unavoidable pesticide residues in the production process of ginseng oral liquid products affect the safety of the oral liquid, but there is no report on how to control the degradation of pesticide residues in ginseng oral liquid.

Contents of the invention

The purpose of the present invention is to provide a method for controlling six prohibited and restricted pesticide residues in ginseng oral liquid, such as thiafos, tefenthion, diazinon, thionof, imidacloprid, and fenpropathrin, through irradiation degradation. The method can effectively, quickly, safely and reliably reduce the residues of various pesticides in the ginseng oral liquid, so that the maximum residue values of the six types of pesticides in the ginseng oral liquid can reach the national standards of the European Union and the like.

The technical scheme that the present invention takes is:

Using high-energy electron beams as radiation sources to treat ginseng oral liquid containing six prohibited and limited pesticides (thionon, fenfofos, diazinon, thionon, imidacloprid, and fenpropathrin) to degrade the pesticides The high-energy electron beam is generated by an electron accelerator, the energy of the electron accelerator is 7.5MeV, and the electron irradiation dose is 2-15kGy; the applicable range of pesticide residues in ginseng oral liquid is 0.05-0.5mg/kg.

For ginseng oral liquid with pesticide residue higher than 0.5mg/kg, it should be diluted and then irradiated. 10mL medicament bottle) and mixed so that the mixed pesticide content is lower than 0.5mg/kg.

During the irradiation process, the uniformity of the radiation dose received by Ginseng Oral Liquid should be ensured, so that the ratio of the highest received dose to the lowest received dose is between 1.5 and 2, and the maximum should not be greater than 2.

The specific degradation process and steps are as follows:

Dissolve various standard pesticides for testing in acetonitrile to prepare a mixed standard solution with a concentration of 10mg/kg; add the above mixed standard solution to 10mL blank commercial ginseng oral liquid to make six prohibited and restricted pesticides The residual concentration is 0.05~0.5mg/kg, the ginseng oral liquid sample is placed under the irradiation window of the electron accelerator; the electron accelerator is turned on for electron beam irradiation; the energy of the electron accelerator is 7.5MeV, and the electron irradiation dose is 2~15kGy ; The concentration of the sample solution before and after irradiation is detected by high performance liquid chromatography-tandem mass spectrometry, and its degradation rate is known. The higher the irradiation dose, the higher the degradation rate.

In the experiment of the present invention, the concentration of the pesticide standard sample added in the ginseng oral liquid is 0.2 mg/kg, and this method is applicable to the pesticides whose limit standard is between 0.05 and 0.5 mg/kg.

Effect of Irradiation on the Quality of Ginseng Oral Liquid

The irradiated ginseng oral liquid samples were used to determine the content of ginsenosides. The results showed that the irradiation treatment had no statistically significant difference (p<0.01) on the content of ginsenosides in the ginseng oral liquid samples compared with the control. It can be seen that under this irradiation dose, the quality of the ginseng oral liquid is not affected while achieving the controlled degradation of the six pesticides such as methadion.

Relevant mechanism and principle of the present invention:

Electron beam irradiation technology is an effective advanced oxidation technology. Irradiation treatment can make water molecules in ginseng oral liquid be irradiated by electron beams to produce hydration free electrons eaq ^- , OH·, H·, etc. The reactivity is very high These substances can react with the weak links in the molecular structure of the pesticides such as methapon, fenfofos, diazinon, thionon, imidacloprid, and fenpropathrin in the ginseng oral liquid, such as dehalogenation, Irradiation chemical reactions such as bond breaking degrade the six target pesticides, so that the maximum limit value of pesticides can reach the standards of the European Union and other countries. The relevant research results have not been reported so far.

Advantage and positive effect of the present invention are:

At present, the research on the degradation and removal of pesticides in ginseng oral liquid is still in its infancy, and there are few reports at home and abroad, and there is no particularly ideal method. Since irradiation is the only technology that can simultaneously produce strong oxidants and strong reductants with high and almost equal concentrations in the water system, it is especially suitable for the degradation of pesticides in oral liquid products. Compared with other treatment technologies, irradiation technology has wide adaptability, does not need to add any chemical reagents, is safe and reliable without secondary pollution, has fast reaction rate and high degradation efficiency. When irradiated at 15kGy, the degradation rates of the six pesticides involved in the method were all over 30%.

The innovation of the present invention is mainly reflected in the following points: one is that the present invention uses electron beams as the radiation source; the other is the selection of the radiation dose; the third is that the present invention firstly uses the ginseng oral liquid base of a representative Chinese herbal medicine as the treatment object; The fourth is that the present invention has selected representative banned and restricted pesticides such as difenfos, difenthion, diazinon, thionfos, imidacloprid, and fenpropathrin among Chinese herbal medicines.

Description of drawings

Fig. 1 is the degradation curve of multiple pesticides in ginseng oral liquid under different irradiation dose conditions of the present invention.

Detailed ways

In order to further understand the content of the invention, features and effects of the present invention, the following examples are given hereby, and detailed descriptions are as follows in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited thereto:

Example 1

A kind of irradiation processing method of ginseng oral liquid:

Select the ginseng oral liquid commodity of 10mL brown bottle on the market for use, and this commodity does not contain six kinds of pesticides such as methadon involved in the present invention through inspection. The selected six kinds of pesticide standard solutions to be tested were added to the ginseng oral liquid commodity with reference to the limit standards of countries such as the European Union, and the added concentration was about 0.200 mg/kg. Three parallel samples were set up during irradiation, and a blank control was set up at the same time. The ginseng oral liquid sample added with the above solution was placed under the irradiation window of an electron accelerator, irradiated with a dose of 5 kGy, and the electron accelerator was turned on for electron beam irradiation.

After the sample solution before and after irradiation was extracted by the following pretreatment method, it was detected by high performance liquid chromatography-tandem mass spectrometry, and the degradation rate of the pesticide was obtained.

Pre-processing method:

Weigh about 10 mL of the mixed ginseng oral liquid into a 50 mL centrifuge tube, add 10 mL of 1% acetic acid acidified acetonitrile, 2 g of sodium chloride, 0.5 g of disodium citrate sesquihydrate, 1 g of sodium citrate, ultrasonically extract for 10 min, add 5g anhydrous magnesium sulfate, vortex for 1min, centrifuge at 8000r/min for 5min, transfer the supernatant to a 15mL centrifuge tube, add 100mg PSA, 100mg C18 and 1g anhydrous magnesium sulfate in the centrifuge tube, shake vigorously for 1min, 10000r /min centrifuged for 5min, and the supernatant was filtered through a 0.22μm filter membrane for UPLC-MS-MS determination.

Preferred chromatographic conditions: Chromatographic column: ACQUITYUPLC BEH C18 column, 2.1×10mm, 1.7μm; column temperature: 25°C; mobile phase: methanol + 10mmol/L ammonium acetate; injection volume: 5μL; flow rate: 0.25mL/min.

Preferred mass spectrometry conditions: ion source: electrospray ion source; scan mode: positive ion scan; acquisition mode: multiple reaction monitoring mode MRM; capillary voltage: 3.12kV; desolvation temperature: 400°C; Hr; Taper hole blowback flow rate: 50L/Hr.

The results showed that the degradation rate of methadon was 14.9%, and the residual amount was 0.186mg/kg, which met the limit standards of EU, Japan and other countries; the degradation rate of fenpropathrin was 25.9%, and the residual amount was 0.145mg/kg, which met the European Union, South Korea and other countries limited standards.

Table 1 (1) Contents and irradiation degradation rates of 6 pesticides in ginseng oral liquid after irradiation

Table 1 (2) Contents and irradiation degradation rates of 6 pesticides in ginseng oral liquid after irradiation

Example 2

The irradiation dose in Example 1 was changed to 15kGy, and all other conditions were unchanged. The degradation rate of imidacloprid is greater than 90%, which belongs to significant degradation, the degradation rate of fenpropathrin is greater than 50%, and the degradation rates of the other four pesticides are also more than 30%.

The data of Examples 1-2 are detailed in Table 1.

Example 3

In Example 1, the irradiation dose was changed to 10kyG, the additive dose was changed to 0.05mg/kg, and the rest of the conditions remained unchanged. The degradation rate of tefenthion is 14.6%, and the residue is 0.043mg/kg, which is in line with the EU and other countries' residue limit standards.

Example 4

In Example 1, the irradiation dose was changed to 10kyG, the additive dose was changed to 0.5 mg/kg, and the rest of the conditions remained unchanged. The degradation rate of diazinon was 22.5%, and the residue amount was 0.388mg/kg, which was in line with the residue limit standards of the European Union and other countries.

The results show:

Four comparison examples find that, electron beam irradiation of the inventive method can effectively reduce multiple pesticide residues in the ginseng oral liquid, make it reach the limit standard of countries and regions such as European Union, and the degradative effect of six kinds of pesticides increases with irradiation The dose increases (Figure 1 shows the degradation curves of multiple pesticides in ginseng oral liquid under different irradiation doses). The degradation results of the tested pesticides after irradiation in this example have the advantages and positive effects described in the present invention.

Claims (5)

1. A method for utilizing radiation to degrade pesticide residues in ginseng oral liquid, characterized in that: taking high-energy electron beams as radiation source to contain six kinds of banned and restricted pesticides such as methapon, fenfofos, diazinon, voltaic The ginseng oral liquid of thionoxafos, imidacloprid and fenpropathrin is processed to degrade the pesticide; the high-energy electron beam is produced by an electron accelerator, the energy of the electron accelerator is 7.5MeV, and the electron irradiation dose is 2～15kGy; The concentration of the sample solution before and after exposure was determined by high performance liquid chromatography-tandem mass spectrometry to determine its degradation rate. 2. The method according to claim 1, characterized in that: in the degradation experiment, the concentration of the pesticide standard sample added in the ginseng oral liquid is 0.2 mg/kg, and this method has a limit of 0.05 to 0.5 mg/kg. Pesticides are applicable. 3. The method according to claim 1, characterized in that: for the pesticide content in the ginseng oral liquid is higher than 0.5mg/kg, it is diluted and then irradiated, and the dilution is to add a blank ginseng without pesticides for oral administration liquid mixed, so that the mixed pesticide content is lower than 0.5mg/kg. 4. The method according to claim 1, characterized in that: during the irradiation process, the uniformity of the radiation dose received by the ginseng oral liquid must be ensured, and the ratio of the highest received dose to the lowest received dose is 1.5-2. 5. The method according to claim 1, characterized in that: the ginseng oral liquid sample containing the six kinds of prohibited and restricted pesticides is placed under the irradiation window of the electron accelerator; the electron accelerator is turned on to carry out electron beam irradiation; The energy is 7.5MeV, and the electron irradiation dose is 2-15kGy; the concentration of the sample solution before and after irradiation is determined by high performance liquid chromatography-tandem mass spectrometry to determine its degradation rate.