Centre for Analytical Science, Loughborough University, Leicestershire, UK.
J Breath Res. 2013 Mar;7(1):017102. doi: 10.1088/1752-7155/7/1/017102. Epub 2013 Feb 27.
This study sought to identify if detectable changes in human breath profiles may be observed following a psychological intervention designed to induce stress, a paced auditory serial addition test (PASAT). Breath samples were collected from 22 participants (10 male and 12 female) following a double cross-over randomized design with two experimental interventions. One intervention required participants to listen to classical music chosen to be neutral. The other intervention required participants to undertake a PASAT that induced cardiovascular responses consistent with acute stress. Both interventions also involved two sequences of cognitive function tests. Blood-pressure and heart-rate were recorded throughout each intervention and distal breath samples were collected onto Tenax® TA/Carbograph 1 thermal desorption tubes, using an adaptive breath sampler. Samples were collected before and after the PASAT. Breath samples were analysed by thermal desorption gas chromatography-mass spectrometry. Data registration using retention indexing and peak deconvolution followed by partial least-squares discriminant analysis identified six stress sensitive compounds. A principal components analysis model based on these components generated a model that predicted post-PASAT versus post-neutral intervention samples with a sensitivity of 83.3% and a selectivity of 91.6% for females, compared to 100% sensitivity and 90% selectivity for males. Of the six compounds indole, 2-hydroxy-1-phenylethanone, benzaldehyde, and 2-ethylhexan-1-ol were identified on the basis of mass spectral, retention indexing and confirmation against pure standards. 2-methylpentadecane was tentatively identified from mass spectral and retention indexing, whilst one component has yet to be assigned, although the mass spectrum is indicative of a terpene. Indole and 2-methylpentadecane concentrations increased in response to the PASAT intervention, while the other compounds reduced in their abundance in human breath, possibly as a result of ventilation effects.
本研究旨在探讨一种旨在诱导应激的心理干预（ paced auditory serial addition test，PASAT）后，人类呼吸谱是否会发生可检测的变化。采用双交叉随机设计，对 22 名参与者（10 名男性和 12 名女性）进行了两次实验干预。一次干预要求参与者听选择的中性古典音乐。另一次干预要求参与者进行 PASAT，以引起与急性应激一致的心血管反应。这两种干预都涉及两种认知功能测试序列。在每个干预过程中都记录血压和心率，并使用自适应呼吸采样器将远端呼吸样本收集到 Tenax® TA/Carbograph 1 热解吸管上。在 PASAT 前后收集样本。通过热解吸气相色谱-质谱法分析呼吸样本。使用保留指数和峰解卷积进行数据登记，然后进行偏最小二乘判别分析，确定了六种应激敏感化合物。基于这些成分的主成分分析模型生成了一个模型，该模型预测 PASAT 后与中性干预后样本的模型，女性的灵敏度为 83.3%，选择性为 91.6%，而男性的灵敏度为 100%，选择性为 90%。基于质谱、保留指数和与纯标准的比较，鉴定出六种化合物中的吲哚、2-羟基-1-苯乙酮、苯甲醛和 2-乙基己-1-醇。2-甲基十五烷是根据质谱和保留指数进行推测的，而一种成分尚未分配，但质谱表明其为萜烯。吲哚和 2-甲基十五烷的浓度随着 PASAT 干预而增加，而其他化合物在人类呼吸中的丰度降低，这可能是通气效应的结果。
