Potassium Bromate Assay by Redox Titrimetry Using Arsenic Trioxide

Published

February 1, 2003

Author(s)

J M. Smeller, Stefan D. Leigh

Abstract

Bromate, a disinfectant, is one of the analytes of interest in wastewater analysis. Environmental laboratories have a regulatory need for their measurements to be traceable to NIST standards. Bromate is not currently certified as a NIST Standard Reference Material (SRM). A traceable assay of potassium bromate (KbrO₃) is needed. KbrO₃ was dissolved in water and assayed by redox titrimetry using arsenic trioxide (As₂O₃). A nominal (0.1 g) sample of As₂O₃ was dissolved in 10 mL of 5 mol/L sodium hydroxide. The solution was acidified with hydrochloric acid, and about 95 % of the KBr(₃ titrant was added gravimetrically. The end point was determined by addition of dilute (1:3) titrant using an automated titrator. The KbrO₃ assay was determined to be 99.76 % ¿ 0.20 %. The estimated uncertainty considered the titrations of three independently prepared KbrO₃ solutions.

Citation

Journal of Research (NIST JRES) - of

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NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

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Citation

Smeller, J. and Leigh, S. (2003), Potassium Bromate Assay by Redox Titrimetry Using Arsenic Trioxide, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50806 (Accessed October 10, 2025)