Islam Mohammad T, Shi Xiangyang, Balogh Lajos, Baker James R
Center for Biologic Nanotechnology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
Anal Chem. 2005 Apr 1;77(7):2063-70. doi: 10.1021/ac048383x.
Polyamidoamine (PAMAM) dendrimers of different generations with various terminal groups were analyzed, for the first time, using a combination of high-performance liquid chromatography (HPLC), size exclusion chromatography (SEC), and matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) techniques. Separation of amine-terminated dendrimers from generation 1 through generation 9 (G1NH(2)-G9NH(2)) was achieved using reversed-phase HPLC with elution time increasing gradually as the density of terminal amine groups increases as a function of generation. Furthermore, separation of dendrimers with terminal amino, acetamide, hydroxyl, and carboxylate groups was obtained. It has also been shown that HPLC can be used to separate dendrimers based on some structural defects inherent during the syntheses of PAMAM dendrimers. MALDI-TOF mass spectra of G1NH(2) identify the major imperfections present during typical synthesis processes. The absolute molar masses (M(n)) and molar mass distributions of the dendrimers were measured using the SEC system equipped with multiangle laser light scattering and refractive-index detectors. Findings from this study suggest HPLC can be a vital tool for characterization and preparative separation of PAMAM dendrimers.
首次采用高效液相色谱（HPLC）、尺寸排阻色谱（SEC）和基质辅助激光解吸/电离飞行时间（MALDI-TOF）技术相结合的方法，对具有不同端基的不同代数的聚酰胺-胺（PAMAM）树枝状大分子进行了分析。使用反相HPLC实现了从第1代到第9代胺端基树枝状大分子（G1NH(2)-G9NH(2)）的分离，随着端胺基团密度随代数增加，洗脱时间逐渐增加。此外，还实现了具有端氨基、乙酰胺基、羟基和羧基的树枝状大分子的分离。研究还表明，HPLC可用于基于PAMAM树枝状大分子合成过程中固有的一些结构缺陷来分离树枝状大分子。G1NH(2)的MALDI-TOF质谱图确定了典型合成过程中存在的主要缺陷。使用配备多角度激光散射和折射率检测器的SEC系统测量了树枝状大分子的绝对摩尔质量（M(n)）和摩尔质量分布。本研究结果表明，HPLC可以成为表征和制备分离PAMAM树枝状大分子的重要工具。
