Chromatography Forum

Hi,

I'm using a normal phase column (hypersil ODS 3micron pore size, 250mm length, 4.6mm ID). What is the best solvent(s) to clean the column with?
Also no peaks detected when running standard samples (using UV detection)
Thanks

Hi Aman,

If your hunch is that the analyte stays in the column thus no peak is to be seen, then cleaning the column is the last action you should consider. Of course it eventually should be cleaned, should it be the case, but there are several things you should give a higher priority. However, if you still insist on that hypothesis, you should inject the standard a couple of times and record the backpressure – it usually rises for each injection, provided the stuff never leaves the column. Another test you could do is just removing/shortcutting the column and injecting a standard. In this case you should see a peak at the beginning of the run.
Still I’d suspect the detector to be malfunctioning or inappropriate parameters (e. g. detection wavelength) if I didn’t see a peak upon injection of a well-defined standard solution.

Best Regards

Your probably using a normal phase column OR a reversed phase column (ODS), but not both. And the pore size is probably 120A (not 3micron).

Per Bryan and danko's comments, there are some inconsistencies in your description. Can you be more precise as to the "standards" you are running:
- what are the standards?
- what is your mobile phase?
- what is the flow rate?
- what detector wavelength?