Due to the variety of targets, large structural differences, and low target content, the detection of pesticide residue method requires being accurate, rapid, sensitive, simple and low cost. The QuEChERS method is more and more widely used in pesticide residue detection, as it is green and quick. The method was developed by the National Association of Analytical Chemists in January 2007.
The US Department of Agriculture scientists first introduced it in 2003. Researched by the US Department of Agriculture’s Agricultural Research Service Center, the material is not placed in the SPF column but directly added to the sample. After a thorough validation of more than 200 pesticides, the improved method was officially adopted in January 2007 as the official method of the American Association of Analytical Chemists.
Overview
The method is characterized by extracting with a buffered salt of acetonitrile (1% acetic acid solution), leaching the target into an organic phase, and then salting out with anhydrous magnesium sulfate, and the anhydrous magnesium sulfate has the function of absorbing water, with the better effect of salting-out. It should be noted that the salt pack should not be added too fast, because the salt pack will saturate the water underneath, and the salt pack will generate heat and agglomerate, which will decompose sensitive pesticides.
The method is characterized by extracting with a buffered salt of acetonitrile (1% acetic acid solution), leaching the target into an organic phase, and then salting out with anhydrous magnesium sulfate, and the anhydrous magnesium sulfate has the function of absorbing water, with the better effect of salting-out. It should be noted that the salt pack should not be added too fast, because the salt pack will saturate the water underneath, and the salt pack will generate heat and agglomerate, which will decompose sensitive pesticides.
The organic phase and the aqueous phase are separated by centrifugation, and then an aliquot is separated from the organic liquid layer and further purified by dispersive SPE. The main function of the dispersed SPE is through non-polar interaction and polar interaction. The ionic interaction selectively retains the matrix interference component for purification purposes.
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