The manganese sulphate bath method is widely used for measurements of neutron source strength. In this study, the analytical
chemistry method based on the Inductively Coupled Plasma (ICP) spectrometry was used for examining the impurity contents of
MnSO4·H2O, to induce55Mn(n,γ)56Mn reactions. From the analytical results, mainly K, Co, and Zn as well as trace amounts of Cd, Li, etc., have turned out
to be the relevant impurities absorbing the neutrons and the fraction of neutron absorbed by the total impurities was determined
to be 1.37%.