Can we reuse the glass silca column after use. How can we wash our silica glass column chromatography after separation?
Washing by MeOH, It is not nice to reuse silica gel after washing. However, you can reactivate silica gel after washing in oven at 120 for at least 2-3 hrs. The effeciency of the adsorbent will be much less than before and you can only use it again for gross fractionation, not for isolation
One can wash with methanol, and even follow that wash with a water wash (google silica HILIC, silica is run with water), and dry in an oven as mentioned above, but the silica won't quite be the same, although it may be good enough for your purposes. The moisture content will be different than when it was manufactured, causing a change in selectivity and efficiency for polar compounds. The pH might be changed, again affecting polar compounds with acidic or basic groups. Finally, retained materials that won't wash off the silica will reduce the capacity of the silica.
I am not sure about the preparative scale glass columns, but for HPLC work, silica which has been boiled in acid say 0.1 M aq. HCl is no different (chromatographically) than silica beads directly from the bottle from the manufacturer in HILIC mode. For normal phase it may make a difference depending on your drying conditions.
dear i am talking about preparative scale glass column. i have use methanol then water then some concentration glacial acetic acid but still not yet clean. i need to reuse silica coz silica is very expansive. Kindly help me if you have any idea
Is your silica discolored or you are not getting any separation? What is your separation criterion for being clean. The cleaning procedure will depend on the type of compounds this silica was exposed to. If you share more details about the type of compounds this column was used, people might be able to suggest better solutions for recycling.
well my compounds are polar in nature. now im able to wash with water.
i wash with 1ltier of water to clean it.
Now it look to be clean as i can see white silica.
can i reuse now?
before reuse do i need to sterilize ?
You don't need to sterilize (maybe you mean heat?), but your silica is saturated with water. You need to bake the silica to drive off the water. The first reply mentioned drying the silica at 120° C. Even than, the moisture content may be different than when the silica was first purchased, so the peaks may elute differently from the first use of the silica.
I had used Chromic acid , it will clean all kind of debris that are sticked on silica beads. Go for it....Good luck
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