Legendre B L, Moberg D L, Williams D C, Soper S A
Department of Chemistry, Louisiana State University, Baton Rouge 70803-1804, USA.
J Chromatogr A. 1997 Aug 29;779(1-2):185-94. doi: 10.1016/s0021-9673(97)00405-6.
A sensitive fluorescence detector for capillary electrophoresis consisting of a semiconductor near-infrared diode laser and a single photon avalanche diode (SPAD) is described. The sensitivity of this system was demonstrated by the separation and analysis of four tricarbocyanine dyes using capillary electrophoresis and a running buffer consisting of 98% methanol and 2% water with 40 mM borate (pH 9.4). The LOD for the dye, IR-132, was found to be 4.41 zmol with the dynamic range found to be approximately four orders of magnitude in concentration. Based on the sampling volume of the system, the number of molecules actually detected at this LOD was approximately 27. To further demonstrate the utility of this diode-based detector, various amino acids were derivatized with a highly anionic near-IR labelling dye. The conjugates were separated in a running buffer comprised of predominately methanol and a cationic surfactant added to reverse the electroosmotic flow. The LOD values for various amino acids were found to be in the low zmol range.
描述了一种用于毛细管电泳的灵敏荧光检测器，它由半导体近红外二极管激光器和单光子雪崩二极管（SPAD）组成。通过使用毛细管电泳以及由98%甲醇、2%水和40 mM硼酸盐（pH 9.4）组成的运行缓冲液对四种三碳菁染料进行分离和分析，证明了该系统的灵敏度。发现染料IR-132的检测限为4.41 zmol，动态范围在浓度上约为四个数量级。基于该系统的进样体积，在此检测限下实际检测到的分子数约为27个。为了进一步证明这种基于二极管的检测器的实用性，各种氨基酸用一种高阴离子近红外标记染料进行衍生化。在主要由甲醇和添加的阳离子表面活性剂组成的运行缓冲液中分离缀合物，以逆转电渗流。发现各种氨基酸的检测限在低zeptomole范围内。
