What are pesticide residues and pesticide residues?

Introduction: In agricultural production, there may be a certain demand for pesticides, which is a guarantee to improve the production quality of agricultural products, and can also expand the benefits. When we buy fruits and vegetables in our daily life, we will be very careful about the pesticide residues in them, but most people cannot distinguish between pesticide residues and pesticide residues.

We must not only grasp its meaning, but also grasp these hazards so that our health is safeguarded.

First, the meaning of some professionals said that pesticide residues refer to the use of pesticides, the residue in biology, agricultural and sideline products and the environment contained in trace amounts of pesticide progenitors. It also contains some toxic metabolites, degradants and various impurities. The amount of residue is also the amount of residue, and most of the samples per kilogram are based on milligrams or micrograms.

to make representations. Pesticide residues are a series of normal phenomena after the use of pesticides, but the time and quantity of residues are different, but residues are inevitable.

Second, the harm to agricultural and sideline products in general, the dosage of pesticides, methods and time will not exceed the national standard, so as to reduce the amount of pesticide residues, and there will be no corresponding harm, but if it exceeds a certain standard, there will be some negative effects. Pesticides will remain on some agricultural and sideline products, and then, it will have a certain impact on the food we often eat in our daily life, if people often eat such food, then it will cause certain harm to people's bodies.

3. Harm to the environment When some workers spray pesticides, some pesticides will remain on crops and weeds, and some will fall into the soil, or even fall into the nearby soil and waters. Although it does not directly cause poisoning, it can seep into the groundwater and carry it into the river in other ways, which will have an impact on the surrounding environment. Although this effect will not be immediately apparent, it will have a series of negative effects on the environment over time.

Pesticide residues refer to the general term for trace amounts of toxic metabolites, degradants and impurities of pesticide protogens that remain in organisms, agricultural and sideline products and the environment after the use of pesticides. Pesticide residues are an inevitable phenomenon after the use of pesticides, but the residual time is long and short, and the purpose of studying pesticide residues is to reduce the amount of pesticide residues and the adverse effects of pesticide residues on human environmental ecosystems through rational use of drugs.

Pesticide residues are found on the surface of ripe vegetables or fruits. Pesticide residues can affect human health.

When tested with a spectrophotometer (412 nm wavelength), calculate the inhibition rate as follows: inhibition rate (%)0 δ t) 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 nerve conduction 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.

Among them, extraction and purification are the pretreatment parts, and 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 chromatographic 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. Look!

<> pesticide residues: After the application of pesticides in agricultural production, some pesticides are directly or indirectly left in grains, vegetables, fruits, animal products, aquatic products, and soil and water bodies. Some of the pesticides applied to crops are attached to the crops, and some are scattered in the soil, atmosphere and water, and some of the pesticides left in the environment will be absorbed by plants. Before the Second World War, pesticides used in agricultural production were mainly inorganic substances containing arsenic or sulfur, lead, copper, etc., as well as plant organic matter such as pyrethrin and nicotine.

1. What are pesticide residues?

1. Pesticide residues refer to the phenomenon that some pesticides are directly or indirectly left in grains, vegetables, fruits, animal products, aquatic products, and soil and water bodies after the use of pesticides in agricultural production. Pesticide residue is also a general term for trace pesticide progenitors, toxic metabolites, degradants and impurities that remain in organisms, harvests, soil, water and atmosphere without being decomposed in a period of time after pesticide use.

2. Some of the pesticides used on crops will be attached to crops, and some will be scattered in the soil, atmosphere and water environment, and some of the residual pesticides will be absorbed by plants. Residual pesticides will directly reach humans and animals through plant fruits or water and atmosphere, or finally pass to people and animals through the environment and food chain.

3. The phenomenon of pesticide residues is produced with the mass production and widespread use of pesticides. Before World War II, pesticides used in agricultural production were generally inorganic substances containing arsenic, sulfur, lead, copper, etc., as well as organic substances from plants, such as pyrethroids and nicotine. During the Second World War, synthetic organic pesticides gradually began to be used in agricultural production.

So far, the annual output of chemical pesticides in the world is nearly 2 million tons, and about 1,000 kinds of synthetic compounds are used as pesticides, fungicides, algaecides, insecticides, defoliants and other pesticides.

Second, what components are mainly detected for pesticide residues

1. The main detection components.

The main components detected for pesticide residues are organophosphorus, carbamate, and pyrethroids (drugs containing these three components are the main insecticides on the market). In particular, organophosphorus insecticides still play a leading role in production and are the preferred insecticides for most vegetable farmers.

2. The necessity of testing.

1) The production of agricultural products is increasingly dependent on pesticides, antibiotics, hormones and other exogenous substances, and the dosage of pesticides in vegetables, grains, fruits, tea and other crops is very high, which will lead to excessive pesticide residues in agricultural products and affect the safety of consumers.

2) Consumers are susceptible to illness or stunted growth after eating food with excessive pesticide residues, and even poisoning and death in severe cases.

3) Excessive pesticide residues will have an impact on the quality of agricultural products.