驰豫试剂的作用主要是什么？

好象一般来说是为了降低驰豫时间的，可以节省采样时间，应该也有其他用途吧，没用过，仅供参考

常用的驰豫试剂是乙酰丙酮铬(Cr(acac)3 ),它和位移试剂用途不同.

Quantitative Determination of Methylcyclohexanone Mixtures Using 13C NMR Spectroscopy
Abstract
The percentage composition of mixtures of four methylcyclohexanones was determined using 13C NMR spectroscopy as a quantitative analytical method. The data were acquired using standard broadband proton decoupling and inverse-gated decoupling, the latter done both with and without the paramagnetic relaxation reagent chromium(III) acetylacetonate [Cr(acac)3]. The standard broadband decoupled spectrum resulted in percentages far from the actual values owing to the varying nuclear Overhauser enhancements (NOEs) and spin-lattice relaxation times (T1's) of the various carbon atoms. These effects were eliminated in the inverse-gated experiments, and the results were very close to the actual percentages. Before examining the mixtures, the students studied a pure sample of 2-methylcyclohexanone. They assigned the 13C spectrum and determined the T1 of the carbonyl group both with and without Cr(acac)3 using the inversion-recovery method. Then a five-times-T1 delay was inserted between pulses in all subsequent inverse-gated decoupling experiments. This project provides students with valuable experience with modern NMR techniques. These include COrrelated SpectroscopY (COSY), Distortionless Enhancement by Polarization Transfer (DEPT) spectroscopy, HETeronuclear CORrelated (HETCOR) spectroscopy, T1 determination, standard broadband versus inverse-gated decoupling, and the addition of a paramagnetic relaxation reagent to dramatically shorten both the T's and the data acquisition time.

看一个实际例子