基质辅助激光解吸附飞行时间质谱分析缩合单宁的阳离子化问题
缩合单宁,基质辅助激光解吸附飞行时间质谱,黄烷3醇单元,聚合度,,缩合单宁，基质辅助激光解吸附飞行时间质谱，黄烷3醇单元，聚合度,基质辅助激光解吸附飞行时间质谱分析缩合单宁的阳离子化问题
摘 要 以单价金属离子Cs+ 和Na+ 作为离子化试剂，对3种缩合单宁进行基质辅助激光解吸附飞行时间(MALDITOF)质谱分析。加入Na+作为阳离子化试剂，能得到较高质量的质谱图。但由于实验通道中几乎不可能完全去除的K+的干扰而会高估棓儿茶酚/表棓儿茶酚单元的组成比例，从而影响对棓儿茶酚/表棓儿茶酚单元存在与否的判断；选择Cs+作为阳离子化试剂可以避免此问题，但在复杂的缩合单宁分析中，同样因为杂质离子Na+和K+的干扰而使得质谱图变得更复杂；未去离子处理直接对缩合单宁进行MALDITOF质谱分析与去离子并加入Cs+的处理比去离子并加入Na+能检测到更高聚合度的高聚物，检测到离子峰强度最高的聚合物随离子不同而不同。关键词 缩合单宁，基质辅助激光解吸附飞行时间质谱，黄烷3醇单元，聚合度
Prerequisite Knowledge of the Effects of Adduct Ions on Matrixassisted Laser Desorption/Ionization Time of Flight Mass Spectrometry of Condensed Tannins
Xiang Ping, Lin Yiming, Lin Peng, Xiang Cheng
(Department of Biology, School of Life Sciences, Xiamen University, Xiamen 361005)
(Research Center for Wetlands and Ecological Engineering, Xiamen University, Xiamen 361005)
Abstract Three different condensed tannins were analyzed using matrix assisted laser desorption ionizationtime of flight mass spectrometry (MALDITOFMS) by selection of Cs+ and Na+ as the cationization reagents. When Na+ was employed as the cationization reagent, condensed tannins gave the quality MALDITOF spectra, accompanying with the possibility of overevaluation of the gallocatechin/epigallocatechin units because of the influence of remaining K+. It is critical to investigate the appearance of gallocatechin/epigallocatechin units in condensed tannins from specially plant tissues. Cs+ is a suitable substitute for this situation. The more complicated MALDITOF spectrum of the complex condensed tannins from Bruguiera gymnorrhiza leaves was detected by selection of Cs+ as the cationization reagent with the presence of Na+ and K+. Using MALDITOF with no deionization or deionization and selection of Cs+ as the cationization reagent rather than with denionization and selection of Na+, the condensed tannin polymers of higher polymerization degree (PD) was oberved. Meanwhile, the polymer with the highest intensity ion peak changed with different ion adducts. ......
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