Evaluation of fluorescent monochloro-s-triazine reagent for amino acid analysis

The fluorescent reagent 2-chloro-4-methoxy-6-(4-methoxy-1-naphthyl)-[1,3,5]triazine (CMMNT) has been synthesized and used for derivatization of mixtures of a-amino acids. The derivatives were resolved on a Nucleosil(R) C-18 column using a linear gradient of 0.1% aqueous trifluoroacetic acid in acetonitrile and detected by their fluorescence at 415 nm using an excitation of 336 rim. Using a standard the linearity was determined from 0.13 - 26 pmol per amino acid derivative and the detection limit was 6.6 x 10(-2) pmol at a signal-to-noise ratio of 3.5. This approach was used for quantitative, amino acid analysis of total hydrolysates of synthetic peptides and for fluorescence labelling of casein.