Amino Acids Profiles in Biological Media

Abstract

An accurate analytical method was developed to determine amino acids in some biological specimens by GC/MS technique. Stable isotopes provide useful tools for a variety of studies, offering ideal internal standards in quantitative information. Isotopic dilution gas chromatography -mass spectrometry (ID-GC/MS) is the techniques used for quantitative analysis of compounds labeled with stable isotopes. A Trace DSQ Thermo Finnigan quadrupole mass spectrometer coupled with a Trace GC was used. Amino acids were separated on a Rtx-5MS capillary column, 30 m x 0.25 mm, 0.25µm film thickness, using a temperature program from 50 o C, 1 min, 6 o C/min at 100 o C, 4 o C/min at 200 o C, 20 o C/min at 300 o C, (3min). The transfer line temperature was 250 o C, the injector temperature 200 o C and ion source temperature 250 o C; splitter: 10:1. Electron energy was 70eV and emission current, 100µA. The amino acids were purified on a Dowex 50W-W8 exchange resin and were derivatized in a procedure following two steps to obtain trifluoroacetyl butyl esters. The identification of amino acids was obtained by using NIST library but also by using amino acid standards.

Determination of Amino Acids in Corn Seed by Gas Chromatography–Mass Spectrometry

“…Gas chromatography coupled with mass spectrometry (GC-MS) is an excellent technique for amino acid identification and quantitation (Pérez-Palacios et al 2014;Culea et al 2009;Culea, Horj, Iordache, and Florescu 2011;Culea, Horj, Iordache, and Cozar 2011;Hodisan et al 1998;Horj, Iordache, and Culea 2011;Iordache et al 2010;Bara et al 2010;Rö hlig, Eder, and Engel 2009).…”

Comparative Characterization of Basil, Mint and Sage Extracts

“…Amino acids and fatty acids were first derivatizated to obtain trifluoroacetyl ester derivatives in the case of amino acids [6][7][8][9][10][11] and fatty acids methyl esters (FAMEs) for free fatty acids [12][13][14][15][16][17]. Antioxidant activities of extracts were also compared.…”