220 BICARBONATE AND CARBONATE IN SATURATED PASTE EXTRACT
Saturated Paste Extract: HCO3, CO3
Quantification of the bicarbonate (HCO3-) and carbonate (CO32-) in the saturated paste extract by titration with acid.
Summary: This method quantifies bicarbonate (HCO3-) and carbonate (CO32-) levels in a soil water extract, such as from saturated paste extract. Quantitation is by titration with 0.025 N H2SO4. The measurement should be made immediately due to the potential of the extract being super- saturated relative to calcium carbonate (CaCO3). The method has a detection limit of approximately 0.1 meq/L. The analysis requires approximately 200 g of sample but 300 g is requested to allow for quality control samples.
U.S. Salinity Laboratory Staff. 1954. Carbonate and bicarbonate by titration with acid. p. 98. In: L. A. Richards (ed.) Diagnosis and improvement of saline and alkali soils. USDA Agricultural Handbook 60. U.S. Government Printing Office, Washington, D.C.