Butter-Determination of salt (chlorine content).

摘要: Two methods for the determination of the salt (sodium chloride) content of butter (Mohr and Volhard) were compared in an interlaboratory collaborative study. One method was based on the titration of Cl- with AgNO3 in the presence of CrO42- as indicator, commonly known as the Mohr method; the other required a back titration of an added excess amount of AgNO3 with KSCN and Fe2+ as indicator, known as the Volhard method. The values found for repeatability were comparable for each method (0.03%). The reproducibility for the Mohr method was discovered to be slightly better than for the Volhard method (0.05 vs. 0.07%). The Mohr method was adopted as the IDF Standard 12B:1988 - Butter - Determination of salt (Chloride content). Details of both experimental techniques and of the equations required to calculate salt content are given in 2 annexes.