Understanding Pesticide Residue: A Scientific Perspective

As people continue to pursue a green and healthy lifestyle, pesticide residues are receiving increasing attention.

Are pesticide residues really that terrifying? Are the fruits and vegetables we encounter daily completely free of residues? Is it possible to live without using pesticides? What methods can be used to avoid the harm caused by pesticide residues? Additionally, what common testing methods are used to determine if the pesticide residue levels in food are within acceptable limits?

Pesticide residues refer to the trace amounts of pesticide active ingredients, toxic metabolites, degradation products, and impurities that remain in organisms, harvested crops, soil, water, and the atmosphere for a period after pesticide application. These residues primarily originate from the pesticides used during the cultivation process, including various types such as insecticides, herbicides, and plant growth regulators.

Regarding pesticides, we don't need to throw out the baby with the bathwater, and we cannot simply equate pesticide use with toxicity to the human body. The toxicity of pesticides depends on the dosage, and the country has clearly defined the maximum residue limits for each pesticide in the "National Food Safety Standard Maximum Residue Limits for Pesticides in Foods" (GB2763-2021). Only when pesticides exceed these limits or banned pesticides are detected could they pose health risks to humans.

Pesticide residues are unavoidable, so what should we do to minimize the harm caused by pesticide residues?

Pesticide residues are mainly classified into four categories based on their properties: organophosphorus, organochlorine, carbamate, and pyrethroid pesticides, among others.

● According to the function of pesticides, they can be classified as fungicides, acaricides, insecticides, herbicides, etc.

● Methods for removing pesticide residues include:

Rinsing method: However, longer rinsing time is not necessarily better, usually within 5-15 minutes.

Heating method: Boiling in water for about 1 minute.

Light exposure method: Direct exposure to sunlight for about 5 minutes.

Storage method: Utilizing the food's own metabolic processes to degrade pesticide residues.

Peeling method: Since most pesticide residues are on the surface of the food, peeling can effectively remove them.

What are the common methods for detecting pesticide residues?

The main methods include spectrometry, chromatography, chromatography-mass spectrometry, capillary electrophoresis, immunoassay techniques, enzyme inhibition methods, biosensor methods, and in vivo detection methods.

Liquid Chromatography Separation

The application of high-performance liquid chromatography (HPLC) in pesticide residue analysis is becoming increasingly widespread because:

• HPLC is suitable for pesticides and their metabolites that have high boiling points, are not easily vaporized, are thermally unstable, and are strongly polar.
• It can be combined with pre-column and post-column derivatization reactions and mass spectrometry, allowing for automated analysis.
• The advent of new detectors has significantly improved the sensitivity of HPLC.

What are the detection items for pesticide residues? What instruments and pre-treatment products are used?

Welch provides application reports and related instruments and products for reference and discussion among peers.