[Simultaneous determination of 17 underivatized amino acids in donkey-hide glue by reversed-phase high performance liquid chromatography-evaporative light-scattering detection].

An analytical method to determine 17 underivatized amino acids in donkey-hide glue was established with reversed-phase high performance liquid chromatography (HPLC) coupled with evaporative light-scattering detection (ELSD). A Prevail C18 column was used with the mobile phase of acetonitrile-0.7% trifluoroacetic acid containing 5.0 mmol/L heptafluorobutyric acid. Under the condition of solvent gradient elution, the temperature of drift tube was 115 degrees C and the gas flow rate was 2.5 L/min. The 17 amino acids were separated within 25 min. The good linearities between the logarithm of peak area and logarithm of mass concentration of amino acids were obtained in a range of mass concentrations from 0.073 g/L to 2.327 g/L. The recoveries of 17 amino acids were 93.5% - 104.8% with the relative standard deviations (RSDs) of 0.58% - 2.88%. The lowest detection limits of amino acids were from 18.2 mg/L to 54.6 mg/L with 3 times the signal to noise ratio. This HPLC-ELSD method is rapid, simple and accurate. It can be used for the direct determination of 17 underivatized amino acids in donkey-hide glue. It also serves as a good reference for the determination of amino acids in other fields, such as pharmaceutical analysis.