I need help regarding column chromatography. Your help in this regard is really helpful for me.
On which parameters we can select the length and width of column. What size of silica is good for separation.?
I have 50 ml of total sample.
Thanks in advance.
Conflict of interest disclaimer: I do work for Teledyne Isco, mentioned below.
That silica is the same as that packed into the flash columns such as those sold by Teledyne Isco and others. If you look at their column dimensions and flow rates, you'll probably see a solvent velocity of ~7 cm/minute, this will be fairly close to the van Deempter flow rate since they want their users to have good resolution. This way of stating the flow rate allows one to more easily scale the column as the column width changes, and you'll note the reply above mine uses solvent velocity as well. For a 5 cm diameter column, that is around 137 mL/min assuming I did my algebra and math correctly. Make sure you run the column isocratically to determine the optimal flow rate.
If you can get a copy of How to Use Excel in Analytical Chemistry and General Scientific Data Analysis by Robert de Levie, Cambridge University Press, you'll find the calculations that you need (Chapter 6.9 in the 2001 edition).
SolventVelocity = (FlowRate * 4)/( PI * ColumnDiameter^2)
Or use this link: https://www.sensorsone.com/volumetric-flow-rate-and-diameter-to-flow-velocity-calculator/
Please look at the following below links which may help you in your analysis:
http://www.srmuniv.ac.in/sites/default/files/downloads/Column_Chromatography.pdf
http://www.chromedia.org/chromedia?waxtrapp=ilqdcDsHiemBpdmBlIEcCvBwB&subNav=acdseDsHiemBpdmBlIEcCvBwBjB
Thanks
Hi, depending on the number of spots and spot difference from TLC, you should opt the length of column and types of silica gel (60-120, 100-200 or 200-400 mesh), and depending on amount of your compound (g, or mg) you should select the width of the column.
It seems that your question is so general. You need to what type of compound(s) you are planning to separate. With that you can have an idea. Is it RPC?
It seems you want to ask about normal phase chromatography. If so, more the surface area of adsorbent silica slurry, more effective will be separation..that means long columns will give you more efficient separations.
If it is reverse phase chromatography, then there are different types of columns available with specifictions...for that you need to specify what type of sample you want to separate.
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