Tantalum (Ta)

Atomic number: 73
Atomic weight: 180.9479
Average concentration in ocean: 200 fmol/kg
Residence time:  n.d.

Distribution in ocean
Tantalum has a modified, nutrient-like vertical profile.  Concentrations increase with depth, although there is evidence of a subsurface maxima (data).

Speciation
Tantalum is believed present as Ta(OH)50 and Ta(OH)6- in seawater.

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

References & Notes