Objective: To explore influence factors of exhaled breath condensate (EBC) pH detection and establish standard method for EBC pH detection of asthma children.
Methods: EBC samples were collected using Rtube EBC collection system, and pH values were detected by microelectrode method.
Results: The temperatures of sampling condenser tube (from - 18 to 4 degrees C) and duration of collection (from 10 to 30 minutes) has no significant effect on EBC pH of asthma children. After degasification with argon for 4 minutes, the EBC pH became stable. The day to day precisions (relative standard deviation) were 0.74% -1.01%, and the relative deviations between theoretical values and detection values were 0.11% - 0.75% in determining different level of pH standard solutions. The EBC samples for pH detection could be store at - 20 degrees C for 6 months.
Conclusion: The established method by standardizing influence factors is accurate and convenient. It can be used in the detection of EBC pH of asthma children.