Perchlorate ion standard solution: multipath titrimetric approach using three different stoichiometric reactions-towards the establishment of SI traceable chemical standards

摘要

Analyses of chloride ions, and oxyanions of chlorine named hypochlorite, chlorite, chlorate and perchlorate ions, are of interest especially in the fields of controlling water and food qualities. Some of them do not exist as a certified reference material characterized by a metrologically valid procedure, and the lack of the standards currently creates problems with the instrumental analyses. This paper describes an accurate multipath titrimetric determination technique for potassium perchlorate to establish the perchlorate ion standard solution as a certified reference material: acidimetric coulometric titration with cation exchange resin, oxidation-reduction gravimetric titration, and precipitation gravimetric titration. The gravimetric titrations and the coulometric titration are capable of ensuring the traceability of the mass fraction of perchlorate ions and cations in potassium perchlorate respectively to the International System of Units. The comprehensive evaluation of the uncertainties for potassium perchlorate assays was carried out, resulting in the establishment of the standard for perchlorate determinations.