AOAC 955.01

Neutralizing value for liming materials

Applicability: AOAC 955.01 is applicable to liming materials for determining their neutralizing value. This method involves treating a sample with excess acid and then back-titrating with a base to a phenolphthalein endpoint to measure how much acid the material can neutralize.

Purpose: The purpose of AOAC 955.01 is to determine the neutralizing value of liming materials, which is a measure of their ability to neutralize soil acidity. This is done by titrating a prepared sample of the liming material against a standard acid and determining how much of a standard base is needed to bring the solution to a specific pH, usually expressed as a percentage of pure calcium carbonate.