What is the pressure limit of column?
Q1. What is the pressure limit of COSMOSIL columns?
| Column | Pressure Limit | |
|---|---|---|
| Core-Shell Columns | 60 MPa | |
| 2.5 µm, 3 µm Series | 30 MPa | |
| Chiral Columns | 30 MPa | |
| SFC Columns | I.D. 2.1-10.0 mm | 30 MPa |
| I.D. 20.0 mm or more | 23 MPa | |
| CNT Columns | 15 MPa | |
| Other Columns | Analysis Column (I.D. 1.0-7.5 mm) | 20 MPa |
| Preparative Column (I.D. 10.0 mm or more) | 15 MPa | |
A large pressure change may deteriorate columns even within the recommended pressure range.
Q2. What is the flow rate limit?
You can raise the flow rate under the pressure limits stated in Q1.
We recommend using standard flow rate described on Technical Information,
Scale Up and Scale Down(PDF 878 KB) . Generally, higher column pressure corresponds to shorter column lifetime.
Q3. What is the recommended pH range?
| Column | Recommended pH Range | |
|---|---|---|
| COSMOSIL / COSMOCORE Series (silica gel base) |
COSMOSIL C18-MS-II, 3C18-EB | pH 2-10 |
| COSMOSIL C18-AR-II | pH 1.5-7.5 | |
| COSMOCORE C18 | pH 1.5-10 | |
| COSMOSIL CHiRAL A, B, C | pH 2-9 | |
| Other Columns | pH 2-7.5 | |
| COSMOGEL Series (polymer base) | COSMOGEL IEX Series | pH 2-12 |
The table above shows tolerant range for the packing material. Choose an appropriate pH for ionic samples.
Q4. What is the concentration of buffer and salt?
| Column | Buffer and Salt Concentration | |
|---|---|---|
| Reversed Phase, Normal Phase, HILIC |
Buffer concentration: 0.005-0.1 mol/l Additive concentration (trifluoroacetic acid, formic acid or acetic acid)： 0.1-1.0% |
|
| Ion Exchange | COSMOGEL IEX Series | Buffer concentration: 0.02-0.05 mol/l Water miscible organic solvent concentration limit (e.g., methanol): 20% or less |
| Gel Filtration | COSMOSIL Diol Series | Buffer concentration: 0.5 mol/l or less Salt concentration: 0.5 mol/l or less |
| Hydrophobic Interaction | COSMOSIL HIC | Buffer concentration: 0.5 mol/l or less Salt concentration: 2 mol/l or less |
| SFC | Acidic compounds: 0.1% TFA, 0.1% acetic acid, 0.1% formic acid Basic compounds: 0.1% diethylamine |
|
Caution:
- Insoluble compounds may clog columns. Filter buffers and salt solutions before using.
- Deposition of salt during analysis may damage columns or instruments. Use an appropriate buffer concentration so that salt does not precipitate.
- Salt often precipitates when the organic solvent is mixed with the aqueous solution. Be careful when mixing mobile phases.
- After using a mobile phase that contains organic solvent, replace with salt-free mobile phase before using a mobile phase with salt of the same aqueous/organic ratio. Likewise, after using a salt-containing mobile phase, wash with a salt-free solution of the same aqueous/organic ratio before using other mobile phases.
