The Structure Of SPE Cartridge
The tube is the carrier of the adsorbent. Basically, it is made of serum polypropylene, and always in the shape of the injection syringe. Some tubes are also made of glass and used for special analysis. The sizes of the bottom outlet of the tube have been standardized, so they can be applied for different SPE multitube vacuum devices.
The sieve plate is used for fixing the adsorbent and filtering the solvent. Polyethylene is a common material for making the sieve plate. As for special analysis, materials such as Poly Tetra Fluoro Ethylene (PTFE), stainless steel sheet and glass.
The adsorbent is used for separation in the SPE cartridge. The adsorbents including aluminum oxide, florisil and graphitized carbon black which are widely applied in column chromatography at an early stage, can still be used in the solid-phase extraction.
Currently, the most common adsorbent is silica gel adsorbent. However, the organic polymer adsorbent with the advantages of good reproducibility, wide PH range of application and wide applicability, has been a substitute for the silica gel adsorbent in many applications.
It is used for increasing the volume of the container above the tube, and then improve the single loading quantity of the sample.