在聚合物矩阵中对磁性NMR放松:提高灵敏度和选择性抑制嵌入物种 (1H和13CPSR过器)
Eduardo Fernandez-Megia1, Juan Correa, Ramon Novoa-Carballal
1Departamento de Química Orgánica, Facultad de Química, and Unidad de RMN de Biomoléculas Asociada al CSIC, Universidad de Santiago de Compostela, Avenida de las Ciencias, S.N. 15782 Santiago de Compostela, Spain.
Journal of the American Chemical Society
|November 17, 2007
概括
偏磁自旋放松 (PSR) 离子通过减少1H的纵向放松时间 (T1) 而不会扩大线条来增强定量NMR. 这种技术可以在复杂的聚合物混合物中使用新型PSR和PSR-CPMG过器进行选择性信号抑制.
科学领域:
- 分析化学 分析化学
- 聚合物科学 聚合物科学
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
背景情况:
- 定量NMR光谱需要很长的采集时间,因为质子 (1H) 纵向放松时间 (T1).
- 使用NMR来区分复杂的聚合物混合物和生物样本中的成分可能具有挑战性.
- 众所周知,偏磁自旋放松剂 (PSR) 会影响NMR放松时间.
研究的目的:
- 研究将偏磁自旋放松 (PSR) 离子纳入各种聚合物中的实际应用.
- 评估PSR离子对1H纵向放松时间 (T1) 和NMR光谱获取的影响.
- 为使用PSR剂的复杂混合物开发选择性NMR信号抑制策略.
主要方法:
- 在D2O和DMSO-d6中的聚合物 (PLL,PAA,PGA,PVP,多糖化物) 中添加对磁离子 (Gd(III),Cu(II,Mn(II)).
- 测量1H纵向放松时间 (T1) 和横向放松时间 (T2).
- 在1D和2DNMR实验 (COSY,HMQC) 中应用PSR过器和联合PSR-CPMG过器.
主要成果:
- 显著减少 (高达500%) 1H T1放松时间,提高NMR灵敏度和减少获取时间.
- 在添加PSR剂后,没有观察到光谱线宽度的增加或化学转移的变化.
- 使用PSR和PSR-CPMG过器在混合物中成功选择性抑制特定的聚合物和低分子量分子信号.
结论:
- 偏磁自旋放松 (PSR) 离子提供了一种强大的方法来增强定量NMR灵敏度.
- 开发的PSR和PSR-CPMG过技术使复杂混合物中的有效选择性信号抑制成为可能.
- 这种方法为分析基于聚合物的材料和生物系统提供了有价值的工具.
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