PMID- 22960793
OWN - NLM
STAT- MEDLINE
DCOM- 20130705
LR  - 20191210
IS  - 1618-2650 (Electronic)
IS  - 1618-2642 (Linking)
VI  - 405
IP  - 2-3
DP  - 2013 Jan
TI  - Exploiting thermodynamic data to optimize the enantioseparation of underivatized 
      amino acids in ligand exchange capillary electrophoresis.
PG  - 951-9
LID - 10.1007/s00216-012-6298-7 [doi]
AB  - Stereoselective amino acid analysis has increasingly moved into the scope of 
      interest of the scientific community. In this work, we report a study on the 
      chiral separation of underivatized D,L-His by ligand exchange capillary 
      electrophoresis (LECE), utilizing accurate ex ante calculations. This has been 
      obtained by the addition to the background electrolytes (BGE) of NaClO(4) which 
      renders the separations "all in solution processes", allowing to accurately 
      calculate in advance the concentrations of the species present in solution and to 
      optimize the system performances. To this aim, the formation of ternary complexes 
      of Cu(2+) ion and L-lysine (L-Lys) or L-ornithine (L-Orn) with L- and D-histidine 
      (His), and histamine (Hm) have been studied by potentiometry and calorimetry at 
      25  degrees C and with 0.1 mol dm(-3) (KNO(3)) in aqueous solution. The ternary species 
      [Cu(L)(L-His)H](+) and [Cu(L)(D-His)H](+) (where L = L-Lys or L-Orn) show a 
      slight but still detectable stereoselectivity, and the determination of DeltaH degrees  and 
      DeltaS degrees  values allowed the understanding of the factors which determine this 
      phenomenon. The stereoselectivity showed by the protonated ternary species has 
      been exploited to chirally separate D,L-His in LECE, by using the binary 
      complexes of copper(II) with L-Lys or L-Orn as background electrolytes added with 
      the appropriate amounts of NaClO(4).
FAU - Contino, Annalinda
AU  - Contino A
AD  - Dipartimento di Scienze Chimiche, Universita degli Studi di Catania, Catania, 
      Italy. acontino@unict.it
FAU - Maccarrone, Giuseppe
AU  - Maccarrone G
FAU - Remelli, Maurizio
AU  - Remelli M
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120815
PL  - Germany
TA  - Anal Bioanal Chem
JT  - Analytical and bioanalytical chemistry
JID - 101134327
RN  - 0 (Amino Acids)
SB  - IM
MH  - Amino Acids/*chemistry
MH  - Electrophoresis, Capillary/*methods
MH  - Stereoisomerism
MH  - Thermodynamics
EDAT- 2012/09/11 06:00
MHDA- 2013/07/06 06:00
CRDT- 2012/09/11 06:00
PHST- 2012/06/19 00:00 [received]
PHST- 2012/07/23 00:00 [accepted]
PHST- 2012/07/19 00:00 [revised]
PHST- 2012/09/11 06:00 [entrez]
PHST- 2012/09/11 06:00 [pubmed]
PHST- 2013/07/06 06:00 [medline]
AID - 10.1007/s00216-012-6298-7 [doi]
PST - ppublish
SO  - Anal Bioanal Chem. 2013 Jan;405(2-3):951-9. doi: 10.1007/s00216-012-6298-7. Epub 
      2012 Aug 15.