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Cation Exchange Capacity

The method determines the cation exchange capacity (CEC) of soil.  Barium is used to quantitatively displace soil exchangeable cations.  Four deionized water rinses are used to remove excess barium.  A known quantity of calcium is then exchanged for barium and excess solution calcium is measured.  CEC is determined by the difference in the quantity of the calcium added and the amount found in the resulting solution.  The method has a detection limit of approximately 2.0 meq/100g.

Sample amount requested:  15 g

Questions concerning limited sample size can be answered by the UC Davis Analytical Laboratory.

Rible, J. M. and Quick, J. 1960. Method S-19.0. Cation Exchange Capacity.  In: Water soil plant tissue.  Tentative methods of analysis for diagnostic purposes. Davis, University of California Agricultural Experiment Service. Mimeographed Report.