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What does C18 mean in HPLC column?
C18 stationary phases are not identical from one C18 HPLC column to another. C18 simply means that the molecules contain 18 carbon atoms, so the other atoms in the molecule can vary, leading to significantly different substances.
What is particle size in HPLC column?
Particle size is the average particle size of the packing in the HPLC column. A 5 µm column would be packed with particles with a definite particle-size distribution because packings are never monodisperse. Particle size distribution is the measure of the distribution of the particles used to pack the LC column.
What is the pressure limit for HPLC column?
Check your programmed max pressure limit. Operating pressure limits for regular HPLC systems (not UHPLC) are often in the range of 5800 – 7000 psi (400 – 500 bar), which is usually also appropriate for HPLC column hardware and (fully porous particle) packing material.
What is difference between C8 and C18?
C18 has 18 carbon atoms while C8 has only 8 carbon atoms. C18 has a longer carbon chain, but C8 has a shorter one. C18 has higher retention while C8 has shorter retention. C18 has higher hydrophobicity, but C8 has a lower hydrophobicity.
What is pore radius?
Here we determined the critical pore radius, which is the radius of the largest sphere that can freely pass through a porous medium, using the water expulsion method, an experimental technique measuring the pressure at which gas passes through a water-saturated porous medium.
What is the difference between pore size and particle size?
The surface area of the particle is inversely proportional to the pore diameter; therefore, a 3 mm particle with a 120 nm pore diameter will have more than twice the surface area of a 3µm particle with a 300 nm pore diameter. A pore diameter of 10 – 13 Da is recommended for samples in the range of 3,000 – 10,000 Da.
How do I reduce column pressure in HPLC?
Filtering samples, using high-quality solvents (or filter solvent), and routine system maintenance are all recommended to prevent excess pressure in your HPLC column and system.
Why choose GL Sciences’ HPLC columns?
Thank you for choosing GL Sciences’ HPLC columns. GL Sciences’ HPLC columns are subjected to a rigorous array of QC test in the ISO 9001 compliant facility, with special emphasis on reagent purity, raw material traceability and consistency in raw materials, and final products.
What are the parameters of an HPLC?
The parameters of the HPLC, like any instrument, are important and are dependant on your sample. The solvent mixture, containing a strong solvent and a weak solvent, will depend on whether your sample is polar in nature or not. Common solvents include water, methanol and acetonitrile.
What are the recommended operating temperatures for column chromatography?
Lower operating temperatures are recommended for longer column lifetime at pH 1 ～2 or pH 9 ～ 10. Additionally, it is recommended to have an organic solvent (e.g., methanol) present in your mobile phase.