Optimization of derivatization conditions of selected amino acids with FMOC-Cl

Chiral HPLC method (mobile phase methanol/0.5% triethylammonium acetate buffer, pH 6.0 40/60 (v/v), teicoplanin based chiral stationary phase, fluorescence detection - - ex 254 nm, em 314 nm) was used for studying a recovery of derivatization procedure for D/L-alanin, D/L-valin, D/L-leucin and D/L-isoleucin. 9-Fluorenylmethyl chloroformate (FMOC-Cl) was used as a derivatization agent. The influence of derivatization temperature (22, 40 and 60 řC) and pH value of 0.2 M NaHCO3 (8.5 - 9.5) on derivatization recovery was monitored in terms of D-enantiomer peak areas for the individual amino acid. The optimal derivatization conditions were found to be pH 8.5 and temperature 40 řC. The developed method was applied to analysis of the real sample, food supplement BCCA Extreme Pure, containing L-isoleucin, L-leucin and L-valin. The sample was D-enantiomers free. Key words: chiral HPLC, teicoplanin, amino acids, derivatization, 9-fluorenylmethyl chloroformate (FMOC-Cl)