deoxygenated

Deoxygenated is an adjective describing a state in which oxygen has been removed or is present at very low levels. It is used across disciplines such as chemistry, biology, medicine, and environmental science. In general, deoxygenation refers to the removal of oxygen from a substance or environment, and its opposite is oxygenated.

In chemistry and materials science, deoxygenated (or degassed) solvents and gases are prepared to prevent oxidation or reactions with dissolved oxygen. Common methods include purging with an inert gas, vacuum degassing, and freeze–pump–thaw cycles. In reactions, deoxygenation can also refer to steps that remove oxygen atoms from substrates or products, or to conditions that minimize exposure to air and moisture.

In biology and medicine, deoxygenated blood has a lower content of dissolved oxygen compared with arterial, oxygenated blood. It returns to the lungs for oxygenation. In tissues, cells consume oxygen during metabolism, producing deoxygenated conditions locally. The term is also used for deoxyhemoglobin, the form of hemoglobin not bound to oxygen, which has different optical and binding properties than oxyhemoglobin.

In environmental science, deoxygenation of water bodies refers to a reduction of dissolved oxygen, often due to microbial respiration, nutrient loading, or warming. Low oxygen levels can create hypoxic or anoxic conditions that stress aquatic life and disrupt ecosystem balance.

See also: oxygenated, hypoxia, anoxia, degassing, deoxygenation.