Abstract

The universality of low molecular weight metabolites (i.e. amino acids, steroid hormones) allows rapid and straightforward investigation of biochemistry of genetically un-characterized species. Thus in vivo metabolic profiling of amino acid in combination with multivariate data analysis (metabolomics) offers great potential in comparative biology. In this paper, amino acid profiles in biological fluid (media) were studied by using HPLC/FLD. HPLC procedure for amino acids require the formation of derivatives due to the low absorption of the free compounds. o-Phthalaldehyde (OPA) used in association with a thiol, such as 3-mercaptopropionic acid (3-MPA), is one of the most popular and sensitive reagents, which yield quickly fluorescent iso-indoles at room temperature. To improve unstability of OPA/3-MPA derivatization, we optimized injector programs for fixed injection times. Linear regressions for the standard curves were linear in the range 0.5 - 100.0 ppb, giving correlation coefficents above 0.99. The detection limit were 1.70 pmol(GLU) - 23.81 pmol(SER). It is practically useful when the amount of sample is very low on single cells.