Simultaneous determination of amino acids in soil by reversed phase high performance liquid chromatography by using 6-aminoquinoly-N-hydroxysuccinimidyl carbamate as a precolumn derivatization reagent

A reversed phase high performance liquid chromatographic method for simultaneous determination of 17 amino acids in soil was established. The amino acid samples were mixed with 2-aminobutyric acid as the internal standard, derivatized with 6-aminoquinolyl-N-hydroxysuceinimidyl carbarnate (AQC), and then separated on a XTerra C(18)column using 1.8 mmol/L formate ammonium (pH = 3. 0) and acetonitrile solution as a mobile phase with gradient elution technique. The photodiode detector at 248 nm was utilized for amino acid quantification. All 17 amino acid derivatives were separated well when an optimized elution condition was applied. Consequently, good reproducibility, high sensitivity and high precision of the method were achieved. When the amino acid concentration was set at the range of 25 - 600 mu mol/L, the linear correlation coefficients of the amino acids were above 0.99 and the detector limit of each amino acids was lower than 0.5 pmol. Total ion current chromatograms of mass spectrum of 17 AQC derivatized amino acids were obtained. The method provids a new way for intensifying the study of amino acids in soil and environment.