Investigations on the variability of breath gas sampling using PTR-MS.

摘要: Breath gas analysis is a promising technology in the frame of medical diagnostics. By identifying disease-specific biomarkers breath patients, non-invasive and easy method for early diagnosis or therapy monitoring might be developed. However, to verify this potential develop diagnostic tools based on one essential prerequisite low variability measurement exhaled volatile organic compounds. Therefore, study has been undertaken order identify possible artefacts within application test practice, which analysed by proton transfer reaction-mass spectrometry (PTR-MS). After validating instrumental repeatedly measuring standard gas, sampling evaluated. The latter carried out single samples (mixed expiratory breath) collected over different periods time such as 1 min (10 volunteers, 4 each), h 11 each) several days (11 10 each). were Teflon bags consecutively measured with PTR-MS. It was found that those show variability. This was, however, not case being longer (15–70 days). Under these circumstances, many compounds (VOCs) showed significant day-to-day variation concentration, although collection had performed under same conditions (similar time, technique, sample storage conditions, etc). large assigned influence room air VOCs, have investigated work, other parameters will discussed. also concentrations methanol, acetone isoprene individuals (inter individual variability) much higher than differences volunteer (intra interval.