Studies on arsenite-arsenate system adsorption of arsenate

The arsenic content of soils varies from 0.3–40 p.p.m., but in plants it is rather stationary, being 3 p.p.m.¹⁾ However arsenites and arsenates have been used since long ago as insecticides and herbicides respectively, and hence sometimes large amounts of arsenic are detected in soils where arsenicals have been sprayed continuously. The arsenite-arsenate relations in soils are of particular interest because arsenite arsenic is more toxic to plants than arsenate arsenic.