耗时短、通用性强的固体核磁共振交叉极化定量检测方法

Time-saving and Highly Applicable Quantitative Method Based on Solid-state Nuclear Magnetic Resonance Techniques

设计了r CDPz脉冲序列,结合使用ramp CP技术,提出了rQCPz/rQCPz^(RC)定量检测方法.与QCP/QCP_(RC)方法相比,rQCPz/rQCPz^(RC)更适用于高速魔角旋转条件及T_2~I较长的样品体系.为了评估rQCPz/rQCPz^(RC)方法的准确性,选取丙氨酸、组氨酸及二者的混合物作为检测样品,分别测定了样品分子基团的相对比例及混合物的组分含量.通过对DP,CP和rQCPz/rQCPz^(RC)法测定结果进行比较发现,与CP方法相比,rQCPz/rQCPz^(RC)检测结果的准确度显著提高,且准确度与传统的DP定量方法相当,但实验时间大大缩减.

For most solid samples,direct polarization（DP） consumes extraordinarily long time.QCP/QCP_（RC） method was capable to provide quantitative information in notably short period of time.However,QCP/QCP_（RC） was not applicable for systems with long T_2~I or under high MAS frequency condition.To solve aforementioned problems,rCDPz sequence was designed and rQCPz/rQCPz^（RC） method was proposed.L-Alanine,L-histidine and their mixtures were used to evaluate the accuracy of rQCPz/rQCPz^（RC） method.By comparing among three schemes of cross polarization（CP）,DP and rQCPz/rQCPz^（RC）,it is demonstrated that rQCPz/rQCPz^（RC） provides accuracy equal to that of DP experiment but consumes markedly shorter experimental time.