碳数和官能团对直链易挥发化合物异味阈值的影响规律

Relationship between odor threshold and carbon chain length and functional group of straight chain volatile organic compounds

以具有代表性的异味特征-异味阈值为研究对象,采用三点比较式臭袋法测定了醇类、醛类、酮类、酸类和硫醇类5个系列常见异味化合物的异味阈值,研究了异味阈值与碳链长度之间的关系,并以官能团疏水性参数量化表征官能团结构,研究了异味阈值与官能团类型之间的关系.研究发现,分子碳链长度和官能团类型都能影响异味阈值的大小,其中异味阈值与碳链长度关系为y=axb或lgy=cx+d(y:异味阈值,x:碳原子数);异味阈值与官能团疏水常数π参数关系为y=aebx或lgy=cx+d(y:异味阈值,x:官能团疏水性参数).所得模型能定量描述碳链长度和官能团类型对异味阈值的影响,为异味机理的进一步探索提供了有力支撑.此外,对异味阈值与上述两因素的多元线性拟合及残差分析结果表明,碳链长度和官能团类型能够影响化合物异味阈值,但二者并非异味阈值的完全决定因素,研究决定异味阈值的全面结构因素,需大量后续工作.

The odor threshold values of 5 series of organic compounds including alcohols, aldehydes, ketones, acids and mercaptans were measured by triangle odor bag method. The relationship between odor threshold and carbon chain length and functional logarithmic values of odor threshold molecular） were found respectively. group of molecular was investigated. Good linear relations between and both the two factors （carbon chain length and functional group of The relations could be presented by the following formulas： y = axb or lgy = cx ＋ d （y： odor threshod, x ： carbon chain length） ; bx y = ae or lgy = cx ＋ d （y： odor threshold, x ： hydrophobic descriptor of functional group of molecular）. These two formulas were capable to explain how carbon chain length and functional group affected the odor threshold values. In addition, the results of multiply linear regression and residual analysis showed that the odor threshold of certain compound could not be determined simply by combining the influences of carbon chain length and functional groups.