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 The Lycaeum Forums » Integrate » Science (Moderator: farmerjack)Topic:
 TLC/LIAD/ESI-MS of MDMA, LSD and related compounds

[prolixity]

http://pubs.acs.org/doi/abs/10.1021/ac901514c

TLC/LIAD/ESI-MS of MDMA, LSD and related compounds


Was just browsing this months Analytical Chemistry and saw this.  Kind of rad.

[prolixity]

http://pubs.acs.org/doi/abs/10.1021/ac901514c

TLC/LIAD/ESI-MS of MDMA, LSD and related compounds


Was just browsing this months Analytical Chemistry and saw this.  Kind of rad.

So this technique allows for the easy separation of components from a mixture and then MS analysis without wet-chemical sample preparation.  TLC is extremely simple and combination with laser assisted desorption techniques, allows for the ionization of the sample on the silica plate matrix!  This is similar to MALDI, but in this case the researchers didn't have to extract into solvent and spot onto a MALDI matrix... just taped the plate to a slide, put some glycerol (for more efficient energy transfer from the laser) between the glass and the plate, and let it rip.  Desorption straight into an ESI needle and then into an MS. 

This stuff gets me wet, seriously..

[prolixity]

http://www.bdal.de/solutions/chemistry/lipids.html  Here is a commercial interface of TLC-MALDI which is of interest, though the laser desorption employed by the article authors is way less infrastructure intensive.  They just used a vacuum chamber, laser, esi setup. 

[whateveryouwantmetobe]

Having a conversation with ourselves here?

Looks pretty cool, the question I have though is can the technique replace HPLC-MS, or even come close to getting the same amount of use?  I mean that's the gold standard of separation followed by mass identification.  Where does this have advantage that LCMS does not?

[prolixity]

Having a conversation with ourselves here?

Looks pretty cool, the question I have though is can the technique replace HPLC-MS, or even come close to getting the same amount of use?  I mean that's the gold standard of separation followed by mass identification.  Where does this have advantage that LCMS does not?

Oh totally not.  This would be useful for high-throughput laboratories in which fast sample analysis is key.  It's much easier to spot onto TLC and analyze directly off it. 

Currently, some techniques require TLC for preliminary identification, and then the analyst must cut out the spots, solvate in a matrix, and then inject in MS.. which is just time consuming.

LC is king when it comes to analytical separations, but sometimes we don't need that kind of power.  I mean, an HPLC can cost upward of $60K, while a silica TLC plate is $20. 

[whateveryouwantmetobe]

LOL you still need the MS though.  

Heck it almost looks like a non-analytical yuppie like me could pop open our ESI, set up a little IR laser with a switch and sample holder in between the electrospray and orifice and voila!  I've broken the instrument.  =)

[pylkko]

LOL you still need the MS though.