A METHOD FOR THE DETERMINATION OF TOTAL CARBON AND ALSO FOR THE ESTIMATION OF CARBON DIOXIDE EVOLVED FROM SOILS

Abstract

A rapid method for the estimation of CO2 is given. This method is applicable to the determination of organic C, carbonate C, or C evolved from a soil as CO2. A total C determination can be made in about 45 min. and CO2 determinations at the rate of about 10-20 an hr. A simple CO2 trap is described which combines the bead tower and the use of NaOH with the single titration principle. The CO2 is absorbed in 0.5 N NaOH solution and precipitated as the carbonate by the addition of an excess of 2 N neutral BaCl2. The excess alkali is then titrated with 0.5 N HCl, phenolphthalien being used as the indicator. The difference between the cc. of standard alkali and acid used, multiplied by 3, gives the milligrams of C.