Li Jianguo, Yan Qinyi, Gao Yunlong, Ju Huangxian
Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China.
Anal Chem. 2006 Apr 15;78(8):2694-9. doi: 10.1021/ac052092m.
A novel method for highly sensitive detection of primary and secondary amino acids with selective derivatization using acetaldehyde as a new derivatization reagent was proposed by capillary electrophoresis (CE) coupled with electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II). The precolumn derivatization of these amino acids with acetaldehyde was performed in aqueous solution at room temperature for 1 h. Upon optimized derivatization, the ECL intensities and detection sensitivities of the amino acids were significantly enhanced by 20-70 times. Using four amino acids, arginine, proline, valine, and leucine, as model compounds, their derivatives could be completely separated by CE and sensitively detected by ECL within 22 min. The linear ranges were 0.5-100 microM for arginine and proline and 5-1000 microM for valine and leucine with the detection limits of 1 x 10(-7) (0.5 fmol, arginine), 8 x 10(-8) (0.4 fmol, proline), 1 x 10(-6) (5 fmol, valine), and 1.6 x 10(-6) M (8 fmol, leucine) at a signal-to-noise ratio of 3. The derivatization reactions and ECL process of amino acids were also proposed based on in situ Fourier transform infrared and ultraviolet spectrometric analyses.
提出了一种利用乙醛作为新型衍生试剂进行选择性衍生化，通过毛细管电泳（CE）结合三（2,2'-联吡啶）钌（II）的电化学发光（ECL）对伯胺和仲胺进行高灵敏度检测的新方法。这些氨基酸与乙醛的柱前衍生化在室温下于水溶液中进行1小时。经过优化衍生化后，氨基酸的ECL强度和检测灵敏度显著提高了20 - 70倍。以精氨酸、脯氨酸、缬氨酸和亮氨酸四种氨基酸作为模型化合物，它们的衍生物可通过CE完全分离，并在22分钟内通过ECL进行灵敏检测。精氨酸和脯氨酸的线性范围为0.5 - 100 microM，缬氨酸和亮氨酸的线性范围为5 - 1000 microM，在信噪比为3时，检测限分别为1 x 10(-7)（0.5 fmol，精氨酸）、8 x 10(-8)（0.4 fmol，脯氨酸）、1 x 10(-6)（5 fmol，缬氨酸）和1.6 x 10(-6) M（8 fmol，亮氨酸）。还基于原位傅里叶变换红外光谱和紫外光谱分析提出了氨基酸的衍生化反应和ECL过程。
