Tritiated water

Tritiated water is a form of water where the usual hydrogen atoms are replaced with tritium. In its pure form it may be called tritium oxide (T₂O or ³H₂O) or super-heavy water. Pure T₂O is corrosive due to self-radiolysis. Diluted, tritiated water is mainly H₂O plus some HTO (³HOH). It is also used as a tracer for water transport studies in life-science research. Furthermore, since it naturally occurs in minute quantities, it can be used to determine the age of various water-based liquids, such as vintage wines.

It should not be confused with heavy water, which is deuterium oxide.

Applications

Tritiated water can be used to measure the total volume of water in one's body. Tritiated water distributes itself into all body compartments relatively quickly. The concentration of tritiated water in urine is assumed to be similar to the concentration of tritiated water in the body. Knowing the original amount of tritiated water that was ingested and the concentration, one can calculate the volume of water in the body.

• Amount of tritiated water (mg) = Concentration of tritiated water (mg/ml) x Volume of body water (ml)

• Volume of body water (ml) = [Amount of tritiated water (mg) - Amount excreted (mg)] / Concentration of tritiated water (mg/ml)