STUDY THE CONTENT OF EXHALED BREATH CONDENSATE 33 hour following the flushing of the mouth with DI water was suggested prior to the EBC collection to obtain a rel- evant EBC sample. 4. Conclusion In this work, capillary electrophoresis with contactless conductometric detection was used to study the day-to- day repeatability of the ionic content of EBC. The pH of EBC before and after degasification with a stream of N2 was studied by a pH microelectrode over five con- secutive days. The influence of various foods and drinks on the ionic content of EBC was investigated and exhib- ited significant differences between EBC samples. It has been shown that EBC is influenced by various param- eters. Therefore, healthy individuals or patients should provide their EBC samples in the morning before break- fast/brushing teeth or at least one hour after consuming any food or drink last followed by flushing of the mouth with DI water. 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Med., 2013 51(7), 1343–1361 DOI: 10.1515/cclm-2012- 0593 Hungarian Journal of Industry and Chemistry Introduction Experimental Instrumentation Chemicals Capillary conditioning Results and Analysis EBC sampling procedure Day-to-day repeatability of the ionic content of EBC Day-to-day repeatability of the pH of EBC Other parameters that influence the ionic content of EBC and the pH Conclusion