Taucher J, Hansel A, Jordan A, Fall R, Futrell J H, Lindinger W
Institut für Ionenphysik, Leopoid-Franzens Universität Innsbruck, Austria.
Rapid Commun Mass Spectrom. 1997;11(11):1230-4. doi: 10.1002/(SICI)1097-0231(199707)11:11<1230::AID-RCM3>3.0.CO;2-Z.
A new analytical method using proton-transfer-reaction mass spectrometry (PTRMS) is described for the determination of trace constituents in human breath. PTRMS is sufficiently sensitive and specific that it does not require preconcentration or separation. At its present stage of development it is capable of detecting trace constituents present in air at the part-per-billion level. These capabilities are illustrated for isoprene, one of the most abundant endogenous hydrocarbons. Our results confirm recent observations of a diurnal level variation associated with sleep or wakefulness; a new finding is that young children have much lower levels of isoprene in breath than adults. To address the metabolic origin of human isoprene, we used PTRMS to analyze expired air for allylic C5 alcohols that have been proposed to be non-enzymatic precursors of isoprene. The lack of correlation between peak breath isoprene and these alcohols suggests that the hydrocarbon is formed by some other mechanism.
描述了一种使用质子转移反应质谱法（PTRMS）测定人呼出气体中痕量成分的新分析方法。PTRMS具有足够的灵敏度和特异性，无需预浓缩或分离。在其目前的发展阶段，它能够检测到空气中十亿分之一水平的痕量成分。以异戊二烯为例说明了这些能力，异戊二烯是最丰富的内源性碳氢化合物之一。我们的结果证实了最近关于与睡眠或清醒相关的昼夜水平变化的观察结果；一个新发现是幼儿呼出气体中的异戊二烯水平比成年人低得多。为了探究人体内异戊二烯的代谢来源，我们使用PTRMS分析呼出气体中的烯丙基C5醇，这些醇被认为是异戊二烯的非酶促前体。呼出气体中异戊二烯峰值与这些醇之间缺乏相关性，这表明该碳氢化合物是通过其他机制形成的。
