By Basil on Wednesday, July 14, 2004 - 04:12 am:
Does anyone have a method to control presence of related aminoacids in Valines or Leucine by HPLC using DAD?. Any bibliographic reference would be appreciated.
Thanks
Basil
By SIELC_Tech on Wednesday, July 14, 2004 - 10:18 am:
Check this out. The method describes analysis of underivatized aminoacids by mixed-mode HPLC:
http://allsep.com/makeCmp.php?cmp=Cmp_098
By Basil on Thursday, July 15, 2004 - 01:18 am:
Thanks but with a DAD ? I'm not able to detect the compounds and I don't have an ELSD detector !!!
Basil
By SIELC_Tech on Thursday, July 15, 2004 - 09:16 am:
Basil,
In the application above you can replace TFA with sulfuric acid and analyze aminoacids at 205, 210 nm and see carboxylic group. Sulfuric acid is transparent at 205, 210 (with high quality acid you can even go lower). You don't need ELSD in this case.
By Basil on Friday, July 16, 2004 - 04:23 am:
Does anyone have a method with an MS detector to control Related Substances in AminoAcid ??...
Do you belive that I can use this method with the MS detector since Aminoacids have a good response with ESI MS detector ??
By SIELC_Tech on Friday, July 16, 2004 - 08:20 am:
BAsil,
You can use TFA, formic acid, ammonium formate, ammonium acetate with Primesep columns. What else besides valine and leucine you have in your mixture?
By Basil on Monday, July 19, 2004 - 12:17 am:
Hi,
This is the real problem. I work in a fine chemical company which makes API for pharmaceutical company. Our last step in the synthesis route use valine to obtain the final product. So we need to control every possible related substance in valine and that's why I can't use TLC method from USP or EP, which does not give to us any specific information. We think that we could find all kinds of aminoacids compounds like (leucine, isoleucine, and similar).
I would try to use this method with MS and I woult tell you ny results.
Thanks for all
Basil
By Steve Watts on Wednesday, August 25, 2004 - 01:08 pm:
Basil
You can analyze for all amino acids using a dedicated amino acid analyzer. I am the Product Specialist for the Hitachi L-8800 Amino Acid Analyzer. Email me if you would like to discuss further. Thanks.
Steve Watts
AAA Product Specialist
Hitachi High Technologies America
steve.watts@hitachi-hta.com
www.hitachi-hta.com/lshome
By Kostas Petritis on Wednesday, August 25, 2004 - 05:08 pm:
Basil,
I have published several LC-MS methods for underivatized amino acids analysis (you can see previous descussion in this forum).
Some of these methods can also separate Ile, Leu, Nleu (norleucine) as well as Val, Iva and NVa (norvaline). If you contact me by e-mail I will send you a modified LC-MS-MS method that is more adequate for you problem.
Here are some references:
Determination of 20 underivatized proteinic amino acids by ion-pairing chromatography and pneumatically assisted electrospray mass spectrometry
P. Chaimbault, K. Petritis, C. Elfakir, M. Dreux
J. Chromatogr. A 855 (1999) 191-202
Ion-pair chromatography on a porous graphitic carbon stationary phase for the analysis of twenty underivatized protein amino acids
P. Chaimbault, K. Petritis, C. Elfakir, M. Dreux
J. Chromatogr. A 870 (2000) 245-254
Parameter optimization for the analysis of underivatized protein amino acids by liquid chromatography and ionspray tandem mass spectrometry
K. Petritis, P. Chaimbault, C. Elfakir, M. Dreux
J. Chromatogr. A 896 (2000) 253-263.
Determination of 1-aminocyclopropane-1-carboxylic acid and structural analogue by liquid chromatography and ionspray tandem mass spectrometry
K. Petritis, V. Dourtoglou, C. Elfakir, M. Dreux
J. Chromatogr. A 896 (2000) 335-341.
Simultaneous analysis of underivatized chiral amino acids by liquid chromatography-ionspray tandem mass spectrometry using a teicoplanin chiral stationary phase
K. Petritis, A. Valleix, C. Elfakir, M. Dreux
J. Chromatogr. A 913 (2001) 331-340.
A comparative study of liquid chromatographic detectors for the analysis of underivatized amino acids
K. Petritis, C. Elfakir, M. Dreux
J. Chromatogr. A 961 (2002) 9-21
The simultaneous determination of 1-aminocyclopropane-1-carboxylic acid and cyclopropane-1-1-dicarboxylic acid in Lycopersicum esculentum by high-performance liquid chromatography-electrospray tandem mass spectrometry
K. Petritis, G. Koukaki, E. Koussissi, C. Elfakir, M. Dreux, V. Dourtoglou
Phytochem. Anal. 14 (2003) 347-351
ESI-MS/MS analysis of underivatized amino acids: a new tool for the diagnosis of inherited disorders of amino acid metabolism. Fragmentation study of 79 molecules of biological interest in positive and negative ionization mode
M. Piraud, C. Vianey-Saban, K. Petritis, C. Elfakir, J.-P. Steghens, A. Morla, D. Bouchu
Rapid Commun. Mass Spectrom. 17 (2003) 1297-1311
LC-ESI-MS/MS analysis of underivatized amino acids: a new tool for the diagnosis of inherited disorders of amino acid metabolism. Separation by reversed phase liquid chromatography of 76 molecules of biological interest, using perfuorinated carboxylic acids as ion-pairing reagent
M. Piraud, C. Vianey-Saban, K. Petritis, C. Elfakir, J.-P. Steghens, D. Bouchu
J. Chromatogr. B (2004) in press
Study of selenium distribution in the protein fractions of Brazil Nut Bertholletia escelsa
T. Chunhieng, K. Petritis, C. Elfakir, J. Brochier, T. Goli, D. Montet
J. Agr. Food Chem. 52 (2004) 4318-4322.
Hope the above helps,
Kostas