Mineo Placido, Vitalini Daniele, Scamporrino Emilio, Bazzano Sebastiano, Alicata Rossana
Istituto di Chimica e Tecnologia dei Polimeri, CNR Catania, Viale A. Doria 6, 95125 Catania, Italy.
Rapid Commun Mass Spectrom. 2005;19(19):2773-9. doi: 10.1002/rcm.2123.
The dependence of the calculated average molecular mass of a polyethylene glycol with a large polydispersity on the instrumental parameters adopted in the acquisition of mass spectra using delayed extraction matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (DE MALDI-TOFMS) was investigated. It has been shown that a combined effect of delay times and potential gradients can act on the ion cloud in the source chamber affecting both mass resolution and average molecular mass value of the analyzed polymeric sample. Also examined was a blend of two different polymers (a PEG and a PMMA commercial sample having a similar average molecular mass), which presents an additional problem concerning the discrimination among the different polymer species as a function of the experimental conditions. In this work, the best instrumental conditions to obtain both good resolution and a correct average molecular mass for the examined polydisperse sample are reported.
研究了使用延迟提取基质辅助激光解吸/电离飞行时间质谱（DE MALDI-TOFMS）采集质谱时，具有较大多分散性的聚乙二醇的计算平均分子量对所采用仪器参数的依赖性。结果表明，延迟时间和电位梯度的综合作用可作用于源室中的离子云，影响分析聚合物样品的质量分辨率和平均分子量值。还研究了两种不同聚合物（平均分子量相似的聚乙二醇和聚甲基丙烯酸甲酯商业样品）的混合物，这在根据实验条件区分不同聚合物种类方面带来了额外问题。在这项工作中，报告了为所研究的多分散样品获得良好分辨率和正确平均分子量的最佳仪器条件。
