BIOAVAILABILITY PREDICTION OF AMINO-ACIDS AND PEPTIDES IN NUTRITIVE MIXTURES BY SEPARATION ON NONPOLAR STATIONARY PHASES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND DIRECT UV DETECTION AT 210 NM

A reversed phase high-performance liquid chromatography method was developed to separate amino acids contents in total parenteral nutrition solution and peptides in enteral mixtures. Retention is attributed to hydrophobic interactions between the solutes and the hydrocarbonaceous functions covalently bound to the stationary phase surface. Consequently, the analytes were eluted in the order of their increasing hydrophobicity. The mixtures were analyzed by using gradient elution with increasing content and monitoring the column efluent at 210 nm.