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.