Comparison of cadmium and enzyme-catalyzed nitrate reduction for determination of NO2-/NO3- in breath condensate.

Background: Analysis of NO2-/NO3- in expired breath condensate (EBC) has been proposed as a marker of inflammation in various lung diseases.

Methods: NO2- and total NO3-/NO2- concentrations were determined in EBC collected from healthy and asthmatic subjects. The NO3- was first reduced to NO2-, and total NO2- was detected by colorimetric Griess reaction.