Measurement of Isofurans by Gas Chromatography-Mass Spectrometry/Negative Ion Chemical Ionization

Many methods have been developed to assess oxidative stress status in vivo, which include products of lipid, protein, and DNA oxidation. However, it has long been recognized that most of these methods are unreliable because they lack specificity, sensitivity, or are too invasive for human investigation (1 ). In 1990, Roberts and Morrow described formation of prostaglandin F₂ -like compounds, F₂ -isoprostanes (F₂ -IsoPs), in vivo by nonen-zymatic free radical-induced peroxidation of arachidonic acid (2 ). Measurement of F₂ -IsoPs by gas chromatography-mass spectrometry/negative ion chemical ionization (GC-MS/NICI) has since emerged as one of the most sensitive and reliable approaches to assess lipid peroxidation and oxidative stress status in vivo (3 ,4 ).