Wise Paul M, Miyazawa Toshio, Gallagher Michelle, Preti George
Monell Chemical Senses Center, Philadelphia, PA 19104-3308, USA.
Chem Senses. 2007 Jun;32(5):475-82. doi: 10.1093/chemse/bjm016. Epub 2007 May 7.
Does structural similarity of odorants influence detectability of their mixtures? To address this question, psychometric (probability of correct detection vs. concentration) functions were measured for aliphatic carboxylic acids and selected binary mixtures thereof. Unmixed stimuli included acetic (C2), butyric (C4), hexanoic (C6), and octanoic (C8) acids. Mixtures included C2 + C4, C2 + C6, and C2 + C8. Vapor-phase concentrations of individual compounds, as measured by a combination of solid-phase micro extraction and gas chromatography/mass spectrometry, were always the same, whether presented singly or in a binary mixture. Additivity of detectability was assessed with respect to response addition (independent processing of mixture components). For C2 + C6, for which the mixture components differed by 4 methylene units, and C2 + C8, which differed by 6 methylene units, response addition provided a reasonably good description of detection at all levels of performance. In contrast, for C2 + C4, which differed by only 2 methylene units, detection showed a tendency to exceed additivity at low concentrations but fell below additivity at higher concentrations. These results suggest that interaction among odors in binary mixtures does depend on structural similarity, at least for detection of carboxylic acids. Future studies can determine if this result is particular to carboxylic acids.
气味剂的结构相似性会影响其混合物的可检测性吗？为了解决这个问题，我们测量了脂肪族羧酸及其选定二元混合物的心理测量函数（正确检测概率与浓度的关系）。未混合的刺激物包括乙酸（C2）、丁酸（C4）、己酸（C6）和辛酸（C8）。混合物包括C2 + C4、C2 + C6和C2 + C8。通过固相微萃取和气相色谱/质谱联用测量的单个化合物的气相浓度，无论单独呈现还是以二元混合物形式呈现，始终相同。我们根据响应相加（混合物成分的独立处理）来评估可检测性的加和性。对于混合物成分相差4个亚甲基单元的C2 + C6以及相差6个亚甲基单元的C2 + C8，响应相加在所有性能水平上都能对检测情况提供合理良好的描述。相比之下，对于仅相差2个亚甲基单元的C2 + C4，在低浓度时检测显示出超过加和性的趋势，但在高浓度时则低于加和性。这些结果表明，二元混合物中气味之间的相互作用确实取决于结构相似性，至少对于羧酸的检测是如此。未来的研究可以确定这个结果是否是羧酸所特有的。
