Complexometry with EDTA as a quality control tool for certified single-element aqueous standard solutions

摘要

The capability of complexometric EDTA titrimetry to determine the nominal concentration of the analyte in aqueous single-element standard solutions with an expected expanded uncertainty U of <0.2 % is investigated. A calibration solutions Astasol~? and a standard solutions from internationally recognized producers are tested. The results covering about 40 analytes show that EDTA titrations can be effectively employed for this purpose. Nominal concentrations and their uncertainties are calculated by using numerical Kragten spreadsheets. The metrological traceability of the results is realized through NIST SRM 928 (lead nitrate), which is used for the standardization of the EDTA.