By montfort on Thursday, March 13, 2003 - 07:08 am:
In our lab we are routinely analysing AccQ (Waters) derivatised amino acids from cell culture supernatants. The limiting factor in this is the RP-HPLC analysis. We are using an AccQ tag column. The solvent system is a quarternary system as described by van Wandelen and Cohen. The total run time is approximately 60 minutes per sample. Does anybody know of an optimized system (with for instance a newer type of column) that can do it faster.
By Anonymous on Friday, March 14, 2003 - 12:29 am:
I spent a few days trying to speed up this analysis using different columns and column temperatures without success. The Novapak C18 is critical to the application I suspect. Waters will know if speeding up the analysis is feasible, presumably if it was possible, they would be marketing it?
By fredtepper on Thursday, July 24, 2003 - 05:05 am:
We have developed an alumina nano fiber sorbent that has a high surface area (~300 m2/g)and very low pore volume so most of the surface is exposed. As a filter (1.5 mm thick layer) it is capable of separating out virus to >99.9999% and DNA and RNA to ~99.5%. This separation is effected at flow velocities of 1 cm/sec attainable with a head pressure of only 0.7 Bar. The sorbent is highly electropositive and sorts molecules by charge. It is likely that this material would be a very effective packing for many LC applications.
Fred
Argonide Corp
www.argonide.com
407-322-2500
By Anonymous on Thursday, January 29, 2004 - 07:38 am:
check the waters web site for performance perspectives on this app
By AllsepTech on Thursday, January 29, 2004 - 05:26 pm:
Check our website for the direct analysis of amino acids without any derivatization-good peak shape, LC/MS and preparative chromatography compatible mobile phase:
http://allsep.com/makeChr.php?chr=Chr_009
By Benjamin on Thursday, February 5, 2004 - 07:10 am:
DEar Montfort;
I have worked for years doing AA analysis of many typers of samples. Even though I have very limited experience with AccQ system I would suggest that you try to speed up the separations by using faster flowrates and/or shorter columns of the same type normally employed. I myself succesfully cut the run times in my systems from a 32 minute cycle down to a 12 min one.
It would help if you can "ignore" the separation of some AA pairs that are difficult to resolve or if your needs can be meet with a limited resolution or no resolution of a number of AAs.
I do not recommend you to try any systems not involving derivatizations. Those examples are normally good just to illustrate catalogs, but are of very limited use with real life cases.
Sorry, I am very late with these recommendations, I have been away from this forum for some time.
Good Luck;
Benjamin