Tungsten (W)

Atomic number:	74
Atomic weight:	183.85
Average concentration in ocean:	54 pmol/kg
Residence time:	61,000 years

Distribution in ocean
The tungsten vertical concentration profile is constant, indicating a conservative distribution in the ocean (data).

Speciation
Tungsten is present in the +VI oxidation state as the tungstate anion, WO₄^2-.

Residence time
The tungsten residence time is from Sohrin et al. (1998). It was calculated from the global average river input.

Analysis
Tungsten is determined by inductively coupled plasma mass spectrometry after preconcentration.

References & Notes