Determination of hydrolyzable and free L-tyrptophan from yeast extraction by reversed phase high performance liquid chromatography-diode array detector

A method for determination of hydrolyzable and free L-tyrptophan from yeast extraction by high performance liquid chromatography-diode array detector(DAD)was established in present experiment. In the method, a Alltima ODS-C_(18) column was used with 0.02 mol/L ammonium acetate (pH 6.5) and methanol (80:20, V/V) as mobile phase. The flow rate was 1.0 ml/min. A diode array detector was used and the detection wavelength was 280 nm. The calibration curve was linear over a range from 2.5 μg/mL to 20.0 μg/mL with a correlation coefficient of 0.9999. The detection limit was 0.3 μg/mL, the relative standard deviation was 1.31% (n=6), and the recovery rate of it was 96.4±1.99% (n=3).