Cereal Chem 62:97-102 | VIEW
High Performance Liquid Chromatography Analysis of Amino Acids at the Picomole Level.
G. L. Lookhart and B. L. Jones. Copyright 1985 by the American Association of Cereal Chemists, Inc.
A method was developed for analyzing the amino acid compositions of protein hydrolysates by high performance liquid chromatography (HPLC) in less than 1 hr. Ten picomoles of each of the commonly occurring alpha-amino acids could be reliably determined by the fluorescence of their omicron- phthaldialdehyde (OPA) derivatives. The OPA-derivatization method, which uses ethanethiol as the sulfhydryl reagent, yields amino acid derivatives that are more highly fluorescent than OPA/mercaptoethanol derivatives and are stable for at least 2 1/2 hr. This HPLC method gives a better separation than previously published methods. Amino acid analysis down to the 3-pmol level is demonstrated, and problems associated with analyses at the low picomole level are discussed.