Bonded Silica Phase

1、SILICA

Silica is the most polar SPE sorbent, used to retain polar compounds in samples, particularly compounds with similar structures. In addition, the silica surface silanols have slight anion exchange properties that can be used to remove organic acids and phenols in extracts.

Sorbent Specifications: Surface area: 480 m²/g, Particle size: 40-75 μm, Pore size: 70 Å

2、NH2

NH2 has both polar and weak anion exchange interactions. It can effectively absorb compounds with a polar functional group (-OH, -NH2,-SH, etc.) by hydrogen bonding from non-polar solvents such as hexane. It retains analytes via strongly polar interactions in organic solutions and via weak anion exchange in aqueous solutions.

Sorbent Specifications: Carbon content: 4.5%, Surface area: 200 m2/g, Particle size: 40 - 75 μm, Pore size: 100 Å

3、C18 

C18 is the most broadly used SPE cartridge. It can be used to adsorb most organic compounds, including non-polar, slightly polar and mid-polar compounds, polar materials such as salt cannot be retained on the sorbent.

Sorbent Specifications:  Carbon content: 17.6%, Surface area: 300 m²/g, Particle size: 40-60 μm, Pore size: 120 Å

4、PSA N

PSA sorbent is similar to NH2 sorbent, it contains two different amino groups, one primary and one secondary，offering both normal phase and anion exchange retention mechanisms.  It has two amino groups with pKa = 10.1 and 10.9, respectively. It can be used for the extraction of metal ions by chelating interactions. 

Sorbent Specifications:carbon content: 8%, Surface area: 500 m²/g, Particle size: 50 - 75 μm, Pore size: 100 Å

5、SAX 

SAX has trimethylaminopropyl as a bonded functional group with a very high pKa. Its quaternary ammonium ligand is always positively charged and engenders very strong anion exchange capacity. The presence of the benzene ring in the functional group increases its potential for non-polar interaction. The two properties are quite useful in the absorption of anionic organic compounds from aqueous systems where non-polar compounds are seen.

Sorbent Specifications: Surface area: 510 m²/g, Particle size: 40 - 75 μm, Pore size: 70 Å

6、SCX 

SCX  has benzenesulfonic acid as a bonded functional group with a very low pK_a. Its sulfonic acid ligand engenders strong cation exchange capacity, while the benzene ring gives rise to additional non-polar interactions. SCX is able to extract positively charged basic compounds such as amines.

Sorbent Specifications: Surface area: 510 m2/g, Particle size: 40 - 75 μm, Pore size: 70 Å