多个(重)强峰压制与白酒的核磁共振分析

Suppression of Multiple Intensive Peaks and Nuclear Magnetic Resonance Measurements on White Spirit

利用激发塑型(exc itation scu lpting)方法,结合多频率选择性激发的形状脉冲(shaped pu lse)、13C CPD去偶和修整脉冲(trim pu lse)等手段进行多个(重)强峰的压制,测试了市售白酒的各种1H核磁共振谱图,并根据样品性质对脉冲序列中的各种参数进行了优化。在压制了其中水和乙醇峰后得到的一维、二维谱图中,清晰地呈现了各个微量组分的谱峰以及反映各组分化学结构的相关峰,据此对图谱中各个谱峰进行了指认。实验表明这种方法对酒类产品的分析研究非常有效,可以应用于酒类生产和储存过程的质量控制、产品的真假及产地的鉴别等。

Excitation sculpting sequence in conjunction with a shaped pulse for multi-site selective excitation, 13^C composite pulse decoupling （CPD） and a short trim pulse has been used for nuclear magnetic resonance （NMR） measurements on white spirit sample and parameters in this pulse sequence have been optimized to the sample. 1D and 2D 1^H NMR spectra show flat baseline and almost pure phase behavior and three very intensive peaks （ H20,CH3 and CH2 ） have been suppressed effectively. Peaks in 1^H ID spectrum and especially the cross peaks in 1^H-1^H 2D spectra 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 white spirit researches, such as quality control during production and deposit process and differentiation according to the authenticity and geographical origin etc.