://The Principle of Solid Phase Extraction

The Principle of Solid Phase Extraction

1. Concept: Solid phase extraction is a sample pretreatment method based on chromatographic separation.

2. Composition: Solid phase extraction includes a solid phase (solid adsorbent with a certain functional group) and a liquid phase (sample and solvent). The liquid sample passes through a solid phase extraction device (solid phase extraction column, solid phase extraction membrane, etc.) equipped with a solid adsorbent under the action of positive pressure, negative pressure or gravity.

3. Principle: Since the stationary phase adsorbent has different functional groups, specific compounds can be adsorbed and retained on the SPE column. [This principle is consistent with liquid chromatography molecules and is similarly compatible.] The principle of similar compatibility means that the solute composed of polar molecules is easily soluble in the solvent composed of polar molecules due to the electrical interaction between polar molecules. A solvent dissolved in a non-polar molecule; a solute composed of a non-polar molecule is easily soluble in a solvent composed of a non-polar molecule, and is insoluble in a solvent composed of a polar molecule.

4. Mode:

A. Target compound adsorption mode: When the sample passes through the SPE column, the functional group of the adsorbent acts on the target compound, the target compound remains on the SPE column, and the sample matrix is discarded.

Step:
a. Pretreatment of solid phase extraction column (activated solid phase extraction column)
b. Sample through the column (add sample and pass the solid phase extraction column)
c. Washing (removing impurities)
d. Drying (removing moisture)
e. Elution (elution of target compound)

B. Impurity adsorption mode: When the sample passes through the SPE column, the impurities are adsorbed by the solid phase adsorbent, and the target compound passes through the SPE column and is collected into the container. It is also used as an impurity removal mode and is commonly used in SPE columns for normal phase packing.
a. Pretreatment of solid phase extraction column (activated solid phase extraction column)
b. Sample through the column (add sample and pass the solid phase extraction column)
c. Washing (collecting the target compound) d dry (out of moisture)

5. The required instrument supplies:
a. Solid phase extraction device
b. Nitrogen blower
c. Vacuum pump

2019-04-03T01:45:59+00:00November 22nd, 2018|