Rapid Commun. Mass Spectrom. 2003; 17: 177–182

合成聚和物的结构影响其物理和化学性质的意义。基质辅助激光解吸/电离质谱（MALDI-TOF MS）可用于聚合物的分析，即分子量分布，单体单位，端基和单体共聚物的序列。其中MALDI电离源可电离出单一的、几乎没有破碎的带电分子，使产生的质谱更为简单便于聚合物分析。TOF分析仪可以分析非常高分子量的聚合物，并提供高分辨率的反射仪使质荷比的检测更为准确。最近，苯乙烯寡聚物因其具有蓝光发射特性，成为光学电子器件的候选材料。同时因其具有具有化学稳定性好，荧光效率高，薄膜薄真空沉积技术的可加工性，引发人们的关注。

在使用质谱进行研究的过程中，由于此类苯乙烯寡聚物是难电离化合物为增强其电离，可通过添加碱金属增强其电离能力。即金属离子可与合成聚合物形成配合物，并有效促进极性聚合物阳离子化。北京大学的陈辉教授在2003年研究了碱金属离子与聚合物之间的亲和力。通过研究碱金属氯化物与苯乙烯寡聚物亲和力的不同，得到表观分子量分布(MWD)随阳离子的变化变化幅度高达1-15%。并通过改变添加LiCl溶液的浓度，得到了锂离子可进行阳离子化的最低浓度。

The structure of synthetic polymers influences their physical and chemical properties. Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-TOF MS) can be used for the analysis of polymers, i.e. molecular weight distribution, monomer units, end groups, and monomer copolymers sequence. MALDI ionization source can ionize a single, almost no broken charged molecules, so that the resulting mass spectrum is more simple and convenient for polymer analysis. TOF analyzers can analyze very high molecular weight polymers and provide a high resolution reflector for more accurate measurement of mass to charge ratio. Recently, styrene oligomers have become candidate materials for optical electronic devices due to their blue emission properties. At the same time, due to its good chemical stability, high fluorescence efficiency and the processability of thin film vacuum deposition technology, it has aroused people’s attention.
In the process of using mass spectrometry, since such styrene oligomers are difficult to ionize compounds, the ionization ability can be enhanced by adding alkali metals. Namely, metal ions can form complexes with synthetic polymers, and effectively promote the cation of polar polymers. Professor Chen Hui of Peking University studied the affinity between alkali metal ions and polymers in 2003. The apparent molecular weight distribution (MWD) varies as much as 1-15% with the change of cations by studying the difference of affinity between alkali chlorides and styrene oligomers. By changing the concentration of LiCl solution, the lowest concentration of lithium ion can be cationized was obtained.

DOI: 10.1002/rcm.890

郭子渊