Comparison Of Suppression Methods Of Multiple Solvent Peaks And NMR Measurements On White Spirit

Presaturation, excitation sculpting and WET multiple intensive peaks suppression methods have been used for NMR measurement on white spirit samples and parameters in these pulse sequences have been optimized to the samples. By comparing these three methods, we found that excitation sculpting method in conjunction with a shaped pulse for multi-site selective excitation, pulsed-field gradients (PFG), selective ¹³C CPD decoupling during the selective ¹H pulses and a short trim pulse is the best one on this sample.1D and 2D ¹H NMR experiments with excitation sculpting intensive peaks suppression were done. The spectra show flat baseline and almost pure phase behavior. Three very intensive peaks (HDO, CH₂ and CH₃) have been suppressed effectively. Peaks in ¹H 1D spectrum and especially the cross peaks in ¹H-¹ 2D spectrum from minor components in the white spirit sample were clearly observed, on which spectral assignments and component analysis can be accomplished. This method is shown to be very promising and effective on the drinks researches. It can be widely used for quality control during white spirit production and deposit process, also for determinations according to the authenticity and geographical origin etc.Furthermore, the optimizing experiment conditions can be used inother drinks system, foods and cosmetic etc. for multiple solvent or intensive peaks suppression.