Is there someone with experience in chromatography column packing efficiency determination performed with techniques different from classic pulse HETP and frontal analysis?
Does anyone use ultrasounds for example?
Thanks
Hi Luciano,
have a deeper look into the work of Uwe D. Neue (Waters Coporation):
Article 3 HPLC columns and packings
https://www.amazon.de/HPLC-Columns-Theory-Technology-Practice/dp/0471190373
Unfortunately, he is already deceased, but as far as HPLC columns are concerned, he was a proven expert.
Regards
Markus
Please look at the following below links which may help you in your analysis:
http://www.processdevelopmentforum.com/files/tips/28937207AA1.pdf
http://files.pharmtech.com/alfresco_images/pharma/2014/08/22/8d9dbce3-f181-499a-ac0a-5addebcd6ab9/article-80028.pdf
http://www.bio-rad.com/webroot/web/pdf/lsr/literature/Bulletin_6590.pdf
Thanks
What type of column dimensions are you talking about? Please elaborate your question and little bit of more details? I vaguely recall that people have used NMR to study column beds.
The question was not relative to a specific type or dimension of a column. However , we are currently experiencing some troubles with the packing of a 30 cm diameter stain-steel column, packed with an RP-HPLC resin.
Luciano Capponi I have written very detailed articles on the science behind packing
Article Fundamental and Practical Insights on the Packing of Modern ...
1. What type of issues are you having ?
2. Although your 30 cm diameter is very large, the key idea is to use the right slurry, which in essence is a solvent system which disperses the particles (look under a microscope). I think you must be using a piston based system?
Farooq Wahab thank you very much for the article that I'll read carefully.
The problems we are encountering are of double species: 1) difficult to reach the pre-determined N/m specification (>10000 N/m) 2) Increasing of back pressure during the load that reaches above 40 bars and that brings sometime to a sudden crash of the bed with consequent loose of material in the breakthrough. While these may be common problems for a packing, this behavior appeared after several years where we had not problem at all. Apparently nothing has changed: the hardware is the same, all the spare parts are treated in the same way, the resin is the same, no modifications have been signaled by the vendor, etc. The modification of the behavior of the column is, at the moment, inexplicable.
There seem to be multiple problems. You may wish to do a scanning electron microscopy of the previous batch of particles with this new batch of resin. Are the particles broken/ crushed? It may be possible that this batch of adsorbent is bad. Does it have a significant amount of trapped moisture? Also try a different batch of the same solvents used for packing your column. Water content in solvents may vary and it hurts column packing process very badly in general.
Increasing back-pressure could just be due to poor quality of adsorbent or just the sample is clogging the column.
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