Analytical Sciences


Abstract − Analytical Sciences, 19(9), 1285 (2003).

Development and Evaluation of a GC/FID Method for the Analysis of Free Amino Acids in Quince Fruit and Jam
Branca M. SILVA,* Susana CASAL,** Paula B. ANDRADE,* Rosa M. SEABRA,*  M. Beatriz OLIVEIRA,** and Margarida A. FERREIRA**
*REQUIMTE, Serviço de Farmacognosia, Faculdade de Farmàcia, Universidade do Porto, R. Anibal Cunha, 4050-047 Porto, Portugal
**REQUIMTE, Serviço de Bromatologia, Faculdade de Farmàcia, Universidade do Porto, R. Anibal Cunha, 4050-047 Porto, Portugal
A GC/FID methodology for determination of twenty-one free amino acids in quince fruit (pulp and peel) and jam is described. The sample preparation was simple, involving a SCX Solid-Phase Extraction (SPE) purification step and a fast derivatization with ethyl chloroformate for gas chromatographic analysis. The chromatographic separation was achieved using a CP-Sil 19 CB wcot fused-silica capillary column. Under the chosen conditions, with temperature and pressure programming, this capillary column was able to separate all the amino acids not only in a short time but also with good separation. The GC/FID procedure is rapid, sensitive, reproducible and accurate. The detection limit values for amino acids were low, between 0.004 and 0.115 ug/mL, and the method was precise. As a general rule, the recovery values were high. Due to its rapidity and low cost, this technique can be useful in the quality control of quince products.