Before entering supermarkets or e-commerce platforms, our products will be strictly tested by third-party testing institutions to ensure their respective rights and interests. In the field of food safety, it is essential to ensure that the amount of pesticide residues in food meets national and international standards. As an important part of our daily diet, the safety of corn flour is directly related to our health. There are several steps and methods involved in the detection of pesticide residues in corn flour, and below is a detailed description of how to perform pesticide residue testing in corn flour. So, how to test corn flour pesticide residue detection?
Sample preparation and preparation are the basis of the entire testing process. A certain amount of corn flour sample needs to be accurately weighed and homogenized to ensure that the sample is representative. Next, the pesticide residues in the sample are transferred to the solution, usually using a suitable extraction solvent such as acetonitrile, methanol or acetone, etc., by methods such as ** extraction or ultrasonic-assisted extraction. Proteins, fats, and other macromolecular interferences are then removed from the sample by centrifugation, filtration, and other steps. Finally, the extract usually needs to be concentrated to a certain volume for subsequent detection and analysis.
The detection of pesticide residues is typically performed using chromatography methods, including gas chromatography (GC) and high-performance liquid chromatography (HPLC). Gas chromatography is suitable for the detection of volatile and semi-volatile pesticides, while high-performance liquid chromatography is more suitable for the analysis of polar and thermally labile pesticides. In the specific operation, the instrument is first calibrated and a standard curve is prepared using the standard. The pretreated sample is then injected into the chromatograph, where the pesticide residue is separated in the column and analyzed qualitatively and quantitatively by a detector. The choice of detector is also important, such as electron capture detector (ECD), flame photometric detector (FPD), and mass spectrometry detector (MS).
In order to improve the accuracy and reliability of the assay, a combination of multiplex detection methods is often used. For example, in liquid chromatography-mass spectrometry (LC-MS), liquid chromatography is used to separate different species and then perform accurate mass analysis by mass spectrometry, which can significantly improve the sensitivity and specificity of the detection. In addition, immunoassays such as enzyme-linked immunosorbent assay (ELISA), which are based on the specific binding of antigens and antibodies, are suitable for rapid screening of large numbers of samples.
Quality control is essential throughout the inspection process. Blank controls, matrix controls, and spikes** experiments need to be added to each batch of samples to monitor the accuracy and reproducibility of the entire analysis process. At the same time, the laboratory should be regularly analyzed and assessed for quality control to ensure that all steps meet the corresponding quality assurance and quality control requirements.
The detection of pesticide residues in corn flour is a systematic process, involving multiple links such as sample preparation, pretreatment, chromatography, data processing and quality control. By following standardized testing procedures and using advanced analytical equipment, we can ensure the accuracy and reliability of our test results, thus protecting our health from pesticide residues.