Characterization and relative ionization efficiencies of end-functionalized polystyrenes by matrix-assisted laser desorption/ionization mass spectrometry
Characterization and relative ionization efficiencies of end-functionalized polystyrenes by matrix-assisted laser desorption/ionization mass spectrometry
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DOI：
10.1016/s1044-0305(03)00216-2
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发表时间：
2003-06-01
影响因子：
3.2
通讯作者：
Dasgupta, A
中科院分区：
文献类型：
--
作者：
Cox, FJ;Johnston, MV;Dasgupta, A
通过基质辅助激光解吸/电离 (MALDI) 飞行时间 (TOF) 质谱 (MS) 检测了一系列具有羟基、氢、叔胺和季胺末端官能团的聚苯乙烯 (PS) 的性质和相对电离效率。正如预期的那样，氢和羟基官能化的 PS 通过连接单个 Ag+ 阳离子而电离。然而，除了M + Ag+ 之外，叔胺PS 低聚物还以(M - H)(+) 和(M + H)(+) 形式存在，而季胺PS 低聚物仅电离为M+ 形式。对叔胺 PS 光谱的分析表明，三种离子形式的比例随低聚物长度的变化而变化，这表明电离效率发生了变化。当比较大量样品时，季胺末端官能化的 PS 的电离效率比所有其他研究的高出十倍，这可能是因为官能团上预先存在的电荷。具有羟基和氢官能团的样品具有类似的电离效率，其中叔胺略高，具体取决于分子量。分子量的变化以不同的方式影响相对电离效率，具体取决于末端官能团，尽管平均分子量测量在很大程度上不受末端官能团的影响。如果采取适当的措施，具有不同电离效率的末端官能化聚苯乙烯的定量是可能的。 (J Am Soc Mass Spectrom 2003,14,648-657) (C) 2003 年美国质谱学会。
The properties and relative ionization efficiencies of a series of polystyrenes (PS) with hydroxyl, hydrogen, tertiary amine, and quaternary amine end-functionalities were examined by matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS). The hydrogen and hydroxyl functionalized PS ionized via attachment of a single Ag+ cation, as expected. However, tertiary amine PS oligomers were found in (M - H)(+) and (M + H)(+) forms, in addition to M + Ag+, while the quaternary amine PS oligomers only ionized to the M+ form. Analysis of tertiary amine PS spectra revealed varying ratios of the three ionic forms depending on the oligomer length, pointing to a change in ionization efficiency. When the bulk samples were compared, the quaternary amine end-functionalized PS gave a ten-fold higher ionization efficiency over all others studied, likely because of the preexisting charge on the functionality. Samples with hydroxyl and hydrogen functionalities had similar ionization efficiencies, with the tertiary amine slightly higher, depending on the molecular weight. Changes in molecular weight affected the relative ionization efficiencies in varying fashion depending on the end functionality, though average molecular weight measurements were largely unaffected by end-functionality. Quantification of end-functionalized polystyrenes with different ionization efficiencies was found to be possible if due care was taken. (J Am Soc Mass Spectrom 2003,14,648-657) (C) 2003 American Society for Mass Spectrometry.