Introduction to the chromatographic detection method of pesticide residues, what are the methods for

The use of the pesticide residue detector is as follows: 1Turn on the instrument and warm it up.

2.Place the sample to be tested into the instrument, taking care not to have too much or too little to avoid affecting the test results. 3.

According to the instrument manual, enter the relevant parameters, such as the sample name, number, etc. 4.Start the test and wait for the results.

5.The test results are compared with the national standard to determine whether the standard is exceeded. 6.

If the standard is exceeded, it is recommended to dispose of it or destroy it to protect public safety and human health. When using a pesticide residue detector, you need to pay attention to the following points: 1

Operate in strict accordance with the instructions to avoid errors or damage to the instrument caused by misoperation. 2.Calibration is required prior to testing to ensure the accuracy of the test results.

3.If there are too many or too few samples, it will affect the test results, so it is necessary to select the right amount of samples....

The first thing to know about the types of pesticides is to have an understanding.

1) Organotins.

It is a class of organic compounds containing tin elements, such as potato blast tin, triphenyltin chloride, toadstool tin, ethyl tin and so on.

2) Benzene. It is a class of organic compounds containing benzene ring structure, such as hexachlorobenzene, pentachloronitrobenzene, tobuzin, methyl tobuzin, chlorothalonil, tetrachlorobenzopeptide, etc.

3) Heterocyclics.

It is a class of organic compounds containing heterocyclic structures. There are many varieties of this kind of agent, with a wide bactericidal spectrum, and most of them have systemic effect.

Hey, I don't have a method, but I do have tools related to experiments.

Summary. There are some methods for the rapid detection of pesticide residues: 1. Chemical rapid detection method, mainly based on the redox reaction, the hydrolysate and the detection solution are discolored, and are used for the rapid detection of organophosphorus pesticides, but the sensitivity is low, the use is limited, and it is easy to be interfered with by reducing substances.

2. Immunity analysis methods, the key are radioimmunoassay and enzyme immunity analysis, the most common is enzyme-linked immunoassay (ELISA), according to the non-specific identification and fusion reflection of antigens and antibodies, artificial service antigens must be prepared for small content fertilizers, and immunity analysis can be carried out. 3. The enzyme inhibition method is the most mature and widely used rapid pesticide residue detection technology, which is mainly based on the specific inhibition reaction of organophosphorus and carbamate pesticides on acetylcholinelinease. 4. The face detection method is to use the sensitive reflection of living microorganisms to pesticide residues, such as feeding house flies with samples and observing the lethality rate to judge the amount of pesticide residues.

This method is simple to operate, but the judgment is not smooth, the accuracy is low, and the application field of chemical fertilizer is narrow.

Good. There are some methods for the rapid detection of pesticide residues: 1. Chemical rapid detection method, mainly based on the redox reaction, the hydrolysate and the detection solution are discolored, and are used for the rapid detection of organophosphorus pesticides, but the sensitivity is low, the use is limited, and it is easy to be interfered with by reducing substances.

2. Immunity analysis methods, the key are radioimmunoassay and enzyme immunity analysis, the most common is enzyme-linked immunoassay (ELISA), according to the non-specific identification and fusion reflection of antigens and antibodies, artificial service antigens must be prepared for small content fertilizers, and immunity analysis can be carried out. 3. The enzyme inhibition method is the most mature and widely used rapid pesticide residue detection technology, which is mainly based on the specific inhibition reaction of organophosphorus and carbamate pesticides on acetylcholinelinease. 4. The face detection method is to use the sensitive reflection of living microorganisms to pesticide residues, such as feeding house flies with samples and observing the lethality rate to judge the amount of pesticide residues.

This method is simple to operate, but the judgment is not smooth, the accuracy is low, and the application field of chemical fertilizer is narrow.

Pesticide residue test reports can be tested at local testing institutions or laboratories. These establishments are usually operated by ** or private companies that specialize in providing testing services for agricultural products and food. In many cases, these testing facilities need to be specifically authorized to provide test reports.

Therefore, if you need to test for pesticide residues, you need to find an authorized testing facility or laboratory to perform the test.

In addition to ** institutions and laboratories of private companies, there are many certification bodies that also provide agricultural product testing services. These organizations are usually third-party organizations of Dubidong Heli, and their test results are fair and authoritative. When choosing a testing organization, you can refer to the certification and qualification of the relevant institution, as well as the recent assessment report and user evaluation.

It is important to note that different agricultural products and food products may require different testing methods and standards, so the professionalism of the testing organization and the reliability of the testing method are crucial. You can choose a reliable testing provider to perform your tests after a careful evaluation of them.

In addition, some testing institutions also provide first-class testing platforms for consumers to test pesticide residues in agricultural products and food. These platforms usually require consumers to purchase a test kit, then follow the instructions in the manual to conduct the test on their own, and upload the results to the corresponding platform for analysis. This method is usually inexpensive and convenient, but it requires some technical and operational skills on the part of the penitent consumer.

In summary, pesticide residue testing can be carried out in local testing institutions or laboratories, and it is recommended to choose a certified institution and use the test results as a reference for purchasing agricultural products and food. <>

The following is the general pesticide residue testing process: 1Sample Collection:

In places such as fields or farms, samples of agricultural products to be tested are collected. 2.Sample Preparation:

The collected samples are processed to remove impurities, moisture, etc., and prepared into samples suitable for detection. 3.Pesticide residue testing:

The prepared samples are sent to a professional testing institution for pesticide residue testing. Commonly used detection methods include high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), etc. 4.

Result analysis: According to the test results, judge whether there are excessive pesticide residues in the sample. If there are excessive pesticide residues, further investigation of the cause and appropriate measures are required.

The following is the general pesticide residue testing process: 1Sample Collection:

In places such as fields or farms, samples of agricultural products to be tested are collected. 2.Sample Preparation:

The collected samples are processed to remove impurities, moisture, etc., and prepared into samples suitable for testing. 3.Pesticide residue testing:

The prepared samples are sent to a professional testing institution for pesticide residue testing. Commonly used detection methods include high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), etc. 4.

Result analysis: According to the test results, judge whether there are excessive pesticide residues in the sample. If there are excessive pesticide residues, further investigation of the cause and appropriate measures are required.

When measured by spectrophotometer (412 nm wavelength), the inhibition rate is calculated as follows: inhibition rate (%) = [(δ0 δ t) δ 0] 100.

Under certain conditions, organophosphorus and carbamate pesticides have inhibitory effects on the normal function of cholinesterase, and their inhibition rate is positively correlated with the concentration of pesticides.

Under normal circumstances, the enzyme catalyzes the hydrolysis of neuroconduction metabolites (acetylcholine), and the hydrolysate reacts with a chromogenic agent to produce a yellow substance, and the change value of absorbance with time is measured with a pesticide residue detection instrument, and the inhibition rate can be judged whether the sample contains organophosphorus or carbamate pesticides.

Extended Materials. Pesticide residue analysis in food is the identification and quantification of target compounds in complex matrices. The general analysis process of pesticide residues is extraction-purification-detection.

The classic pesticide residue analysis steps are usually as follows: water-soluble solvent extraction - non-water-soluble solvent redistribution - solid-phase adsorption column clean-up - gas or liquid chromatography detection.

The sample pretreatment not only requires the complete extraction of the components to be tested as much as possible, but also removes the impurities existing at the same time as the target as much as possible, avoids the contamination of the column and detector, reduces the interference of the detection results, and improves the sensitivity and accuracy of the detection. Therefore, extraction and purification are a very important pretreatment steps in the process of pesticide residue analysis, and their quality directly affects the correctness and reliability of the analysis results.

The classic extraction and purification methods mainly include: oscillation leaching, tissue mashing, ultrasonic extraction, Soxhlet extraction, liquid-liquid partitioning, column chromatography, azeotropic distillation and other technologies. With the progress of science and technology, sample preparation technology is developing in the direction of time-saving, labor-saving, cheap, solvent saving, reducing environmental pollution, miniaturization and automation. Hope!

The fast enzyme immunization kit, which I make antibodies, is the same as the food safety one.

Specific BAI method, agricultural industry standard DU761 has! The landlord asks for precautions, so according to the DAO experience to provide you with a few references!

1. When preparing samples in the first step, it is necessary to pay attention to breaking the samples and beating them evenly, so that they can be fully extracted;

2. When weighing the sample, try not to dip the sample bottle close to the mouth of the bottle, which is not easy to wash down when adding acetonitrile extract, which will bring systematic error;

3. When homogenizing, the time is 2min, and the homogenizing time of the sample and the spiked sample should be especially equal;

4. In the filtration step, if the sample containing colloidal is difficult to filter, a suction filter device can be used;

5. The amount of sodium chloride should be appropriate, too little stratification is not obvious;

6. When standing the measuring cylinder with a plug, the time should not be less than 30min, otherwise the stratification of acetonitrile phase and water phase is not complete;

7. In the purification step, the flow rate of nitrogen should not be too large, otherwise it is easy to splash out of the acetonitrile solution, and the evaporation will be close to dry.

8. Transfer to a centrifuge tube, rinse the beaker with about 3ml of acetone in three times, and do not forget to mix well on the vortex shaker before bottling;

If you are on ECD, you need to pay attention to the steps of passing through the column, pre-washing, and conditioning the Flory silicon column, you must not let the column dry, and the same is true when eluting, otherwise it will affect the column and bring errors.

In addition, these steps must be carried out in the ventilated kitchen, otherwise the health of the operator will be affected.

I can only think of so much for a while, I hope it will help you, if you have other questions, welcome the landlord to find me!