DIN EN 14397-1:2010-07

This document specifies a method for the determination of carbon dioxide in solid fertilizers. The method applies to all fertilizers that contain carbonates and/or bicarbonates. The carbon dioxide is liberated by treatment with phosphoric acid and absorbed in a solution of barium hydroxide. Barium carbonate precipitates and the excess barium hydroxide is back-titrated with hydrochloric acid. If the fertilizer containes any other substances that release carbon dioxide on treatment with phosphoric acid, this will also be determined and expressed as carbon dioxide. The method was validated in an inter-laboratory test carried out with 8 laboratories analysing 5 different samples. The statistical results are given in Annex A.