SPE Cartridge - Classification and recommendation
Classification
According to principle of reaction, SPE is divided into the following three categories.
- Normal-phase extraction- Adsorbents used in normal phase extraction is polar.
- Reversed-phase extraction- The sorbent and the target analytes by reversed-phase extraction is usually the non-polar or weak polar, relying mainly on non-polar and non-polar interactions, is a fan of Edward force or dispersion force.
- Ion exchange extraction- is relying on the interaction between target analytes and sorbent.
Selection
Select proper sorbent according to the difference between target analytes and disruptors such as polar, molecular weight and pKa, etc.
Sample Properity | Sample class | Suggesting Cartridge |
Dissolve in Organic | Reversed Phase Sorbent (e.g. methanol) | CN, C18/18A, PSA, HLB |
Normal Phase Sorbent/Bonding (e.g. methanol/water) | NH2, Diol, PSA, Carb-GCB-NH2 , Carb-GCB/PSA | |
Normal Phose Sorbent (e.g. hexane) | Silica, Florisil, Alumina, SLE | |
Dissolve in Water | Cation | SCX, C8/SCX, MCX, PRS |
Anion | SAX, C8/SAX, MAX | |
Reversed Phase Sorbent (e.g. non-ion type) |
For reverse phase, normal phase and adsorption type SPE cartridges, the quantity of target analytes to SPE sorbent ratio is generally not more than 5%. For ion exchange SPE cartridges, need to consider the ion exchange capacity. Provide the conventional ion exchange capacity of Starlab is about 0.3meq/g, the following table for SPE cartridges capacity parameters
Specification |
Maximum Sample Load |
Volume |
Minimum Elution volume |
50-100mg |
2.5mg-5mg |
1mL |
100-200μL |
100-200mg |
5mg-10mg |
3mL |
200-500μL |
200mg-1g |
10mg-50mg |
6mL |
500μL-6mL |
500mg-2g |
25mg-100mg |
12mL |
3mL-10mL |
Merlin Scientific SPE Cartridges are made of medical grade PP and forming in one time. Frits are made of UHMW-PE.