摘要
对不同碳链长度及饱和程度的脂肪酸及二、三元混合脂肪酸体系的低场核磁共振弛豫特性进行了研究。结果表明,除乙酸外,随碳链长度增加,横向弛豫时间(T_2)及单组分弛豫时间(T_(2W))均减小;而随不饱和度增加,二者均相对增大。对棕榈酸-油酸、硬脂酸-油酸混合体系而言,随着油酸比例增加,T_2与T_(2W)均增大;油酸比例大于40%后,会对亚油酸-油酸体系的弛豫响应产生较大影响。随着亚油酸比例增加,各亚油酸-油酸-硬脂酸三元混合体系的T2弛豫时间均增大,峰面积比例(S_(21))减小,而峰面积比例(S_(22))增大,油酸比例越高,峰面积比例的变化幅度减小,T_(2W)均增加,且随体系中油酸(OA)比例的增加变化趋缓。
The chemical structure of fatty acid has a great influence on the relaxation characteristic of lipid. In this work,the low-field nuclear magnetic resonance( LF-NMR) relaxation characteristics of fatty acids with different chain lengths or degree of saturation were investigated firstly,and then the relaxation characteristics of binary or ternary fatty acid mixtures were studied. The result showed that except acetic acid,the T_2 relaxation time and T_(2W) decreased as the carbon chain length increased; but as the unsaturated degree increased,these measures all increased. For the binary fatty acid system,the T_2 relaxation time and T_(2W) of palmitic acid-oleic acid and stearic acid-oleic acid all increased as oleic acid ratio increased. While for the linoleic acid-oleic acid system,only when the oleic acid ratio was above 40%,the relaxation response changed significantly. For the ternary fatty acid system,the T_2 relaxation time of each linoleic acid/oleic acid/stearic acid system increased with the increase of linoleic acid ratio,while the area ratio S_(21)decreased,and S_(22) increased. The higher ratio of oleic acid and the change of the peak area ratio were relatively reduced,and the relative increases of T_(2W) changed more slowly.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2018年第2期281-287,共7页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金项目(No.31201365)资助~~
关键词
脂肪酸
链长
不饱和度
低场核磁共振
弛豫特性
Fatty acid
Chain length
Degree of unsaturation
Low-field nuclear magnetic resonance
Relaxation characteristics
