Amino Acids Determination in Meat by GC-MS

An isotopic dilution gas chromatography - mass spe ctrometric (ID-GC/MS) techniques was used for amino acids determination i n sausage meat. The stable isotope internal standard used was 15 N-Methionine. A Trace DSQ ThermoFinnigan 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 derivatizated in a procedure following two ste ps to obtain trifluoroacetyl butyl esters. The identification of amino acids was obtained by using NIST library but also by using amino acid standards. Concentration of amino acids was determi ned by using matrix calculation for methionine quantitation.