Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: uwants100 on November 26, 2014, 08:37:03 PM
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Hey smart follks,
I currently came across a problem. so when referring to "filtering through pad of silica" in a literature procedure, does it imply I can just pour some dry silica on a fritted funnel and suction filtrate my mixture through?? If not, what does it really mean?
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You can gain useful insight into the characteristics and applications of silica gel c/o http://en.wikipedia.org/wiki/Silica_gel.
In particular, the use of silica gel as an adsorbent in cat litter provides an practical example of "filtration through a pad of silica". Diatomaceous earth, sometimes referred to and marketed under trademarked brand names such as Celite(R), also can be used for this purpose.
Information contained in the following primary literature reference also should prove helpful as you strive to master the fundamentals of organic laboratory techniques; see http://pubs.acs.org/doi/abs/10.1021/ed039p355
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Hey smart follks,
I currently came across a problem. so when referring to "filtering through pad of silica" in a literature procedure, does it imply I can just pour some dry silica on a fritted funnel and suction filtrate my mixture through?? If not, what does it really mean?
It is basically somewhere between a Celite filtration and a very short silica column. It's used to quickly separate compounds with very different retention times - i.e. the separation is so large that the unwanted material is completely immobile in the eluent chosen but the compound(s) of interest will have high mobility. The eluate is normally collected as a single fraction (as with a Celite filtration). It is normally used for either very clean transformations in which there are no impurites with similar (or greater) mobility on silica gel, or as a quick partial purification prior to another more sophisticated purification technique.
A silica pad can prepared in the same way as you would a Celite pad or a (very short) silica column (i.e. not dry but properly packed).
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From the sound of what you would like to accomplish, I'm joining the others and recommending you use Celite.
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Depending on the mixture, celite may not retain the polar material effectively