Pesticide Residue Determination Sample Pretreatment Solid Phase Extraction Technology
Solid phase extraction(SPE) is mainly used for sample pretreatment in liquid chromatography. The principle is to use a solid adsorbent to adsorb the target compound in the liquid sample, separate it from the matrix and interference compound of the sample, and then elute with the eluent. Desorption by heating to achieve the purpose of separating and enriching the target compound.
The solid phase extraction operation steps include column pretreatment, sample loading, washing away interference components, and recovering the components to be tested. The amount of the sample added to the extraction column depends on the size and type of the extraction column, the retention properties of the component to be tested, and the concentration of the component to be tested and the concentration of the matrix component. Another separation of SPE is that impurities are retained on the column and the component to be tested passes through the column. The sample is purified but cannot enrich the component to be tested, nor can it separate impurities that retain properties that are weaker than the component to be tested, that is, the purification is incomplete. Compared with the traditional liquid-liquid extraction method, solid phase extraction overcomes the shortcomings of liquid/liquid extraction technology and general column chromatography, has a high recovery rate of the components to be tested, and can effectively separate the components to be tested and the interference components. Separation, the extraction process is simple and rapid, solvent saving, reproducibility is good, the general analysis only takes 5~10min, which is 1/10 of the liquid/liquid extraction method, and the required solvent is only 10% of the liquid-liquid extraction method, and is reduced. The introduction of impurities reduces the impact of organic solvents on people and the environment.