GC-MS METHODS FOR AMINO ACIDS DETERMINATION IN DIFFERENT BIOLOGICAL EXTRACTS

Abstract

Sensitive, precise and accurate analytical methods for free amino acids determination in biological samples were developed. Purification by ion exchange technique was followed by two steps derivatization method to obtain trifluoroacetyl ester derivatives. GC/MS analysis was performed by using scan or SIM mode. Known amounts of internal standard, the isotopic labelled analogue of glycine, methionine or isoleucine were added to the sample, before extraction, for the quantitative analysis, followed by matrix and regression curves calculation. The methods were validated using amino acid standard samples. Analyses of dairy, corn grain, fish plasma and meat are presented. Also a trace level (picogram) analysis method of blood spots, for diagnosis of inborn errors of metabolism, is described.

Keywords

• amino acids, GC-MS, isotopic dilution, blood