Niobium in Sea-water

Abstract

THE presence of organically bound niobium has been demonstrated in ascidians¹, and unpublished evidence suggests that this niobium is absorbed in some way from sea-water. It is thus of importance to know if niobium can be detected in sea-water and to obtain some indication of its concentration. Consideration of the known amounts of niobium present in an adult Molgula manhattensis, its rate of development, length of life and rate of filtration of water leads one to suppose that if the water current is the sole source of niobium then, in regions where these species and other species of ascidians which utilize niobium flourish, it cannot be present in the sea in less concentration than 0.05 µgm./l. The chromatographic method of niobium analysis developed by Hunt, North and Wells² is capable of revealing the presence of 10⁻⁷ gm. of niobium. At a concentration of 0.05 µgm./l., this amount could be expected in 2 1. of sea-water.