A method is presented for the determination of chromium in sea-and fresh water. Chromium is concentrated on activated carbon
from neutral solution after a previous reduction of chromate with sodium sulfite at pH 1.5. The final determination of the
total chromium content is performed by instrumental neutron activation analysis. By preconcentration on activated carbon a
differentiation between tervalent and hexavalent chromium is possible. A separate determination of both species is not yet
feasible due to the high carbon blank and to the necessity of measuring the adsorption percentage on carbon. The lower limit
of determination, which depends on the value of the carbon blank, is 0.05 μg Cr·1−1 with a precision of 20%.