School of Pharmacy, University of Wisconsin-Madison, 53705, United States.
Anal Chem. 2011 May 1;83(9):3462-9. doi: 10.1021/ac200708f. Epub 2011 Apr 6.
In this work, the utilization of matrix-assisted laser desorption/ionization-mass spectrometric imaging (MALDI-MSI) for capillary electrophoresis (CE) analysis of peptides based on a simple and robust off-line interface has been investigated. The interface involves sliding the CE capillary distal end within a machined groove on a MALDI sample plate, which is precoated with a thin layer of matrix for continuous sample deposition. MALDI-MSI by time of flight (TOF)/TOF along the CE track enables high-resolution and high-sensitivity detection of peptides, allowing the reconstruction of a CE electropherogram while providing accurate mass measurements and structural identification of molecules. Neuropeptide standards and their H/D isotopic formaldehyde-labeled derivatives were analyzed using this new platform. Normalized intensity ratios of individual ions extracted from the CE trace were compared to MALDI-MS direct analysis and the theoretical ratios. The CE-MALDI-MSI results show potential for sensitive and quantitative analysis of peptide mixtures spanning a wide dynamic range.
在这项工作中，研究了基于简单而稳健的离线接口的基质辅助激光解吸/电离质谱成像（MALDI-MSI）在基于毛细管电泳（CE）分析肽中的应用。该接口涉及将 CE 毛细管末端在 MALDI 样品板上加工的凹槽内滑动，该 MALDI 样品板预先涂有一层用于连续样品沉积的基质。沿 CE 轨道进行飞行时间（TOF）/TOF 的 MALDI-MSI 能够实现肽的高分辨率和高灵敏度检测，从而在提供准确质量测量和分子结构鉴定的同时重建 CE 电泳谱。使用这个新平台分析了神经肽标准品及其 H/D 同位素甲醛标记衍生物。从 CE 迹线中提取的各个离子的归一化强度比与 MALDI-MS 直接分析和理论比值进行了比较。CE-MALDI-MSI 结果显示出对跨越宽动态范围的肽混合物进行敏感和定量分析的潜力。
