Component  Chemical(s) used  Stock solution concentration  Concentration/pH tested  Relevance
Salt  Sodium chloride  100 g/L  0, 1, 35 g/L  Salinity of seawater: 35 g/L
Salinity of surface water: 0.01 to few g/L [38]
Lung fluid: ~10 g/L [39]
Protein  Bovine serum albumin  100 mg/mL  0, 100, 1000 μg/mL  Respiratory fluid: 30–8500 μg/mL [25, 40–42]
Surfactant  Sodium dodecyl sulfate  100 μg/mL  0, 1, 10 μg/mL  Lung surfactant: up to 1000 μg/mL [19, 43]
Surface water: less than 1 μg/mL [20]
pH  Hydrochloric acid, sodium hydroxide  NA  4.0, 7.0, 10.0  Ambient aerosol: 0–4 [44, 45]
Inorganic aerosol: basic [46]
Human respiratory fluid: pH-neutral [47]