1. Method for detecting pesticide residues in agricultural products
1.1 Bioassay Bioassay uses specific biochemical reactions of specific organisms to determine the pesticide residues and their contamination. It is not necessary to pre-treat or pre-treat the samples. It is relatively simple and fast, but the requirements for the tested organisms are high. A false positive or false negative condition occurs and the pesticide variety cannot be determined. 1.2 Physical and chemical analysis methods Physical and chemical analysis methods are divided into instrumental detection methods, conventional chemical analysis methods and rapid detection methods. Currently, the most commonly used methods are instrumental detection methods such as gas chromatography and liquid chromatography. Due to the wide variety of pesticides, pesticide residue contamination testing is a trace chemical analysis requiring high technical expertise.
2. Pesticide residue detection steps for agricultural products Pesticide residue detection procedures mainly include sampling, sample preservation, pretreatment (pulverization, extraction/extraction, purification, concentration, etc.), qualitative and quantitative analysis of instruments, processing and analysis of test results. Pretreatment in pesticide residue testing is important. The following highlights the pre-processing.
2.1 Sample homogeneity When testing certain indicators of agricultural products, because the materials are not homogeneous, the composition of each part and the degree of pollution are different, the sample must be crushed and mixed into a homogeneous liquid for testing. How to homogenize agricultural products such as vegetables and fruits? We can use the HBM-400 series tapping homogenizer to add agricultural products and diluents such as vegetables and fruits to the sterile filter sample bag, then put the sample bag into the homogenizer, and close the door to complete the Quality, according to the needs, the required concentration is prepared, and the corresponding analytical instrument is used for the measurement.
2.2 Concentration purification We know that pesticide residue pollution detection is a trace chemical analysis, and the correct choice of test equipment can do more with less. The target substance in the sample is extracted by using a solid phase extraction apparatus and a liquid-liquid extraction apparatus (adding an extractant, using a vertical oscillator, which greatly reduces labor intensity); and concentrating the target substance in the sample using a nitrogen gas blower.
With the increasing application of new technologies, the rapid development of pesticide residue pollution detection technology has been greatly promoted, and the detection efficiency of pesticide residue pollution has been effectively improved to meet the requirements of large sample and low content pesticide residue analysis.
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