Determination of free Amino Acids in Tobacco by Reversed -Phase High-Performance Liquid Chromatography

Ethanol solvent of different concentrations was used for extraction of free amino acids in tobacco. The result showed that the total amount of extracted free amino acids was the highest when ethanol solvent was at concentration of 80%,and the purifying capability of cationic ion-exchange column was the best compared with those of active carbon, ether and 5% sulfogroup-salicylic acid. Reversed-phase high-performance liquid chromatography and precolumn derivatization with OPA and FMOC were employed for determination of free amino acids in tobacco,and simultaneously the secondary amino acids. The contents of 15 free amino acids in Yunnan C2F 98 tobacco was determined by this method. Among them Pro was the highest,and made up about 25% of the total. Thr was the lowest,and made up about 1% of the total.