Kato Masaru, Jin HongMei, Sakai-Kato Kumiko, Toyo'oka Toshimasa, Dulay Maria T, Zare Richard N
Department of Analytical Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada Shizuoka, Shizuoka, 422-8526, Japan.
J Chromatogr A. 2003 Jul 4;1004(1-2):209-15. doi: 10.1016/s0021-9673(03)00451-5.
Capillary electrochromatographic separations of amino acid mixtures were studied using two modified porous photopolymerized sol-gel monolithic columns. One was modified with dimethyloctadecylchlorosilane (DMOS), and the other was modified with DMOS, followed by chlorotrimethylsilane to end-cap residual silanol groups. Prior to separation, amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole using as a mobile phase 50 mM phosphate (pH 2.5), water, and acetonitrile in the ratio of 1:1:8. Five derivatized amino acids (Asn, Phe, Ala, Ile, and Leu) were separated within 7 min. Theoretical plate numbers varied between 58700 and 105000/m. This separation method with the end-capped monolithic column was applied to rat cerebrospinal fluid. The dominant amino acid found was Gln at a concentration of 420 microM along with small quantities of Ser (54 microM).
