Determination of amino acids from hydrolyzed bovine serum albumin by high-performance liquid chromatography-mass spectrometry with fluorescence and electrospray ionization detection

On a reversed-phase Hypersil BDS C-18 (4.6 mm x 200 mm, 5 mu m) column, 20 amino acids derivatized using 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate(BCEOC) as pre-column derivatization reagent were separated in conjunction with a gradient elution. Optimum derivatization, giving the corresponding stable fluorescent derivatives, was obtained the reaction of amino acids with BCEOC at room temperature for 10 min in the presence of sodium borate catalyst in acetonitrile solvent. The fluorescence excitation and emission wavelengths were 333 nm and 390 nm. The identification of amino acid derivatives from hydrolyzed bovine serum albumin was obtained on the basis of electrospray ionization detection at positive ion mode. Linear correlation coefficients for the determination amino acid derivatives are over 0.999, and detection limits (at signal-to-noise of 3: 1) are 6.3 similar to 117.6 fmol for the labeled amino acids.