In this work, the behavior of four different commercially available polarizing agents is investigated employing the non-ionic model surfactant 1-octanol as analyte. A relative method for the comparison of the proportion of the direct and indirect polarization transfer pathways is established, allowing a direct comparison of the polarization efficacy for different radicals and different parts of the 1-octanol molecule despite differences in radical concentration or sample amount. With this approach, it could be demonstrated that the hydrophilicity is a key factor in the way polarization is transferred from the polarizing agent to the analyte. These findings are confirmed by the determination of buildup times T_b, illustrating that the choice of polarizing agent plays an essential role in ensuring an optimal polarization transfer and therefore the maximum amount of enhancement possible for DNP enhanced NMR measurements.

在这项工作中，使用非离子模型表面活性剂 1-辛醇作为分析物，研究了四种不同的市售偏振剂的行为。建立了比较直接和间接极化转移途径比例的相对方法，允许直接比较不同自由基和1-辛醇分子不同部分的极化效率，尽管自由基浓度或样品量不同。通过这种方法，可以证明亲水性是极化从极化剂转移到分析物的方式的关键因素。这些发现通过确定累积时间 T _{b得到证实}，说明极化剂的选择在确保最佳极化转移方面起着至关重要的作用，因此 DNP 增强型 NMR 测量的最大增强量可能。