Oxygen flux

high-resolution terminology - matching measurements at high-resolution

Oxygen flux

Description

Oxygen flux, J_O2, is a specific quantity. Oxygen flux is oxygen flow, I_O2 [mol·s^-1 per system] (an extensive quantity), divided by system size. Flux may be volume-specific (flow per volume [pmol·s^-1·mL^-1]), mass-specific (flow per mass [pmol·s^-1·mg^-1]), or marker-specific (flow per mtEU). Oxygen flux (e.g., per body mass, or per cell mass) is distinguished from oxygen flow (per subject, or per cell).

Abbreviation: J_O2

Reference: Gnaiger 2019 MitoFit Preprint Arch, Gnaiger 2020 MitoPathways, Gnaiger 1993 Pure Appl Chem, Renner 2003 Biochim Biophys Acta

Which SI units should be used?

• Convert volume-specific oxygen flux, J_O2, to units [nmol·s^-1·L^-1] = [pmol·s^-1·mL^-1]

1 µmol O₂∙min^-1 ∙ 16.67 = 1 nmol O₂∙s^-1

1 nmol O₂∙min^-1 ∙ 16.67 = 1 pmol O₂∙s^-1

1 nmol O₂∙h^-1 ∙ 0.2778 = 1 pmol O₂∙s^-1

1 natom O∙s^-1 ∙ 0.5 = 1 nmol O₂∙s^-1

1 natom O∙min^-1 ∙ 8.33 = 1 pmol O₂∙s^-1

1 mL O₂∙min^-1 (at STPD) ∙ 0.744 = 1 µmol O₂∙s^-1

• The difference of oxygen flux per volume and oxygen concentration change per time

The oxygen concentration change per time (= rate of concentration change) is expressed in units [µmol O₂∙L^-1∙s^-1].

By definition the rate of concentration change is zero in an open system at steady-state, when the concentration in the system does not change at any respiratory flux by the sample enclosed in the open system.

Oxygen flux per volume (= volume-specific oxygen flux) is expressed in units [µmol O₂∙s^-1∙L^-1] or [nmol O₂∙s^-1∙L^-1]

By definition the volume-specific oxygen flux is the advancement of reaction per volume of the reaction chamber.

Oxygen flux per mass (= mass-specific oxygen flux) is expressed in units [µmol O₂∙s^-1∙kg^-1] = [pmol O₂∙s^-1∙mg^-1]

By definition the mass-specific oxygen flux is the advancement of reaction per mass of the sample enclosed in the reaction chamber.

MitoPedia concepts: MiP concept, Ergodynamics 

MitoPedia methods: Respirometry