Abstract

One class of lipid peroxidation products, saturated aldehydes, possesses significant volatility at physiological temperatures and are released into the adjacent air, the so-called headspace. Measurement of headspace aldehyde concentrations may offer a means to simply assess lipid peroxidation without disturbing the system being studied. Conventional chromatography-based gas analysis techniques can be cumbersome and slow to perform. Selected ion flow tube mass spectrometry (SIFT-MS) was, however, designed to rapidly quantify trace gases in real time. We have utilized SIFT-MS in a variety of situations in which lipid peroxidation is known to occur to allow the utility of the technique to quantify headspace aldehydes in such ‘real world’ applications. SIFT-MS analyses of oxidised oil headspace indicated the presence of propanal and hexanal in omega-3 and omega-6 PUFA rich oils respectively. Moreover, SIFT-MS analysis suggested the presence of hexanal, and to a lesser extent propanal, in the headspace of cultured cardiac cells, with concentrations increasing following incubation of the cells with hydrogen peroxide. Finally, analysis of the headspace of mouse tissues, including blood plasma, lung, brain, liver and kidney, incubated at room temperature, 40 °C or 60 °C, suggested the presence of these and other aldehydes. Our results suggest that quantification of headspace aldehydes using SIFT-MS may be employed to rapidly and non-invasively investigate lipid peroxidation-associated reactions in a variety of in vitro, and potentially in vivo, applications.

Keywords: Hexanal, propanal, headspace, brain, liver, trace gas analysis, selected ion flow tube mass spectrometry.