Figure 1–
1H-nuclear magnetic resonance spectra of sodium hypochlorite cleaning solution (Milton; Milton Pharmaceutical UK Ltd, Gloucester, UK), which is used for the reusable parts of an EcoScreen condenser, and exhaled breath condensate (EBC) samples. a) A 3.55 mM Milton solution (512 scans). Except for the reference 0.1 mM sodium 3-trimethylsilyl[2,2,3,3-2H4]propionate signal at 0.0 ppm, no other signals were present in the spectrum. b) The absence of contaminant peaks was confirmed in the vertical expansion (×32) of the spectrum and c) in the deionised water used for rinsing the condenser for 5 min (1,024 scans, ×32). Therefore, the EBC spectra (512 scans) of d) a healthy subject and e) a chronic obstructive pulmonary disease patient are not contaminated by the cleaning solution. Spectra were recorded at 300 K.