Clinical application of breath biomarkers of oxidative stress status

Isolation and quantification of volatile breath biomarkers indicative of re levant alterations in clinical status has required development of new techn iques and applications of existing analytical chemical methods. The most si gnificant obstacles to successful application of this type of sample have b een reduction in required sample volume permitting replicate analysis (an a bsolute requirement for all clinical studies), separation of the analyte(s) of interest from background molecules, water vapor and other molecules wit h similar physical properties, introduction of automation in analysis and t he use of selective detection systems (electron impact mass spectrometry, f lame photometric, thermionic detectors), and automated sample collection fr om the human subject. Advances in adsorption technology and trace gas analy sis have permitted rapid progress in this area of clinical chemistry. (C) 1 999 Elsevier Science Inc.