doktor_alternate (Newbee)
05-05-04 23:10
No 505109
      practicality of large scale column chromatography     

if one were to, say... purify a kilo or two of... say... lsd, could a very large column be built of enamel-coated metal  tubing with a glass window down it (however one would practically construct such a device)? i can imagine that such a technique would be most wasteful of solvents and the like. is there a better way to purify such compounds on such a scale that would not require pouring many litres of solvents down the metaphysical drain? reverse phase chromatorgaphy perhaps?



i have seen gel electrophoresis be used to separate peptides and amino acids before... could one build a long trough and run a kilo through that at a time?
imagined disadvantages - uses tons of electricity that might melt the gels at each side... some gel addatives are quite toxic...

whatabout binding the target product to it's favoured d-tartaric acid salt, or the malonic acid salt, then wash it with a NP and re-AB? all these pulls would lose product though...

would an ultra-precise distillation through a series of retort stands followed by a very careful methanol recrystalisation be sufficient, or would one theoretically spend a few days at, say, 5 4-L columns to just push it all through?

ok, here are the answers to my questions.
http://www.westernanalytical.com/btr/Kromasil

High performance spherical silica from analytical to process scale separations

· High mechanical strength
· Chemically stable over wide pH-range
· Large available surface area
· Optimal surface properties for purification of basic compounds


 - - here is another good one:
http://www.albmolecular.com/features/tekreps/vol07/no45/v07n45.pdf
featuring 'simulated moving bed' chromatogaphy among others.
all methods use expensive equippment, though im sure some of you experienced mechanical engineers would beable to dream up some inexpensive alternatives to SMBC.

also in there is a method of purification via liquid-liquid chromatography and resolution via multiple small sample centrifugion (though i think this one topped out at a few grams max. cap.)

anyway, i have to run,but i will keep looking into this stuff, and if anybeez wanna contribute...