These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Assay of aromatic amino acid enantiomers in rice-brewed suspensions by chiral ligand-exchange CE.
    Author: Qi L, Liu M, Guo Z, Xie M, Qiu C, Chen Y.
    Journal: Electrophoresis; 2007 Nov; 28(22):4150-5. PubMed ID: 17941117.
    Abstract:
    The aim of this work was to assay seasoning D- or L-aromatic amino acids (AAs) in rice-brewed suspensions, Laozao in Chinese, by chiral ligand-exchange CE with UV detection and Zn(II) complex as a chiral selecting system. Resolution and peak retention were found to be parallel to the basicity of the AA chiral ligands, and basic L-Arg was known to work the best at pH 8.20 compared with L-Lys and other AA ligands. Baseline separation of DL-aromatic AAs and partially separation of some FMOC-labeled nonaromatic AAs have been achieved using a running buffer of 5 mM ammonium acetate, 100 mM boric acid, 3 mM ZnSO(4), and 6 mM L-Arg at pH 8.20. The aromatic amino acids in four brands of Laozao were measured in a range of 0.25-20 microg/mL for Typ, 1.00-120 microg/mL for Phe, and 2.50-200 microg/mL for Tyr, with linear regression coefficient all over 0.999. The LOD (S/N=3) was 0.15 microg/mL for Typ, 0.50 microg/mL for Phe, and 1.25 microg/mL for Tyr. The recovery of the method determined by spiking with the supernates of Laozao as background was 94.0-112.9%. The RSDs of migration time and peak area measured from six injections of tyrosine were 0.2 and 2.7%, respectively, for run-to-run, and 1.6 and 3.2%, respectively for day-to-day. Interestingly, there were only L-Trp, D-Tyr, and L-Tyr found in the assayed four brands of Laozao. They may serve as an index to recognize the brand of Laozao.
    [Abstract] [Full Text] [Related] [New Search]