Unit for Macromolecular Mass Spectrometry, FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ, Amsterdam, The Netherlands.
J Am Soc Mass Spectrom. 1996 May;7(5):449-57. doi: 10.1016/1044-0305(96)00003-7.
Matrix-assisted laser desorption ionization was performed on an external ion source Fourier transform ion cyclotron resonance mass spectrometer equipped with a 7-T superconducting magnet to analyze end groups of synthetic polymers in the mass range from 500 to 5000 u. Native, perdeutero methylated, propylated, and acetylated polyethylene glycol and polyvinyl pyrrolidone with unknown end-group elemental composition were investigated in the mass range up to 5000 u by using a 2,5-dihydroxybenzoic acid matrix. A small electrospray setup was used for the deposition of the samples. Two methods to process data were evaluated for the determination of end groups from the measured masses of the component molecules in the molecular weight ranges: a regression method and an averaging method. The averaging method is demonstrated to allow end-group mass determinations with an accuracy within 3 mu for the molecular weight range from 500 to 1400 and within 20 mu for the molecular weight range from 3400 to 5000. This is sufficient to identify the elemental composition of end groups in unknown polymer samples.
采用外部离子源傅里叶变换离子回旋共振质谱仪，配备 7-T 超导磁体，进行基质辅助激光解吸电离，分析质量范围为 500 至 5000 u 的合成聚合物的端基。使用 2,5-二羟基苯甲酸基质，研究了未知端基元素组成的天然、氘代甲基化、丙基化和乙酰化的聚乙二醇和聚乙烯吡咯烷酮，质量范围高达 5000 u。采用小尺寸电喷雾装置进行样品沉积。评估了两种数据处理方法，以从分子量范围内的组分分子的测量质量确定端基：回归方法和平均方法。平均方法证明可以在 500 至 1400 分子量范围内，端基质量测定的精度在 3 μ以内，在 3400 至 5000 分子量范围内，精度在 20 μ以内。这足以确定未知聚合物样品中端基的元素组成。
