DIN EN ISO 23470:2011-09

This International Standard specifies a method for the determination of the cation exchange capacity (CEC) and the content of exchangeable cations (Al3+, Ca2+, Fe2+, K+, Mg2+, Mn2+, Na+) in soils using a hexamminecobalt trichloride solution as extractant. The CEC is obtained by difference between the initial quantity of hexamminecobalt in solution and the quantity remaining in the extract after the exchange reaction. The measurement of hexamminecobalt concentration in the extract can be performed by direct spectrophotometric measurement, or by the determination of total ammonium nitrogen or total cobalt concentrations. The quantities of exchanged cations are determined on the same extract using spectrometric methods, such as inductively coupled plasma atomic emission spectrometry (ICP-AES).