Certification of 3180 Series Standard Reference Materials® Anions in Solution

Published

August 26, 2025

Author(s)

Brian Lang, Thomas Vetter, John Molloy, Antonio Possolo

Abstract

The 3180 series Standard Reference Materials (SRMs) are single anion solutions intended for use as primary calibration standards for the quantitative determination of a single anion and are a key link in the traceability chain for analysis measurements of those anions made world-wide. The mass fraction of the anions in these materials are traceable to the International System of Units (SI). The 3180 series SRMs are calibration standards gravimetrically prepared from carefully assayed, high-purity materials dissolved in a water-based matrix with nominal mass fractions of 1 mg/g. The certified values and expanded uncertainties of these SRMs are determined by combining a gravimetric preparation value and a carefully measured ion chromatography instrumental value, taking their associated uncertainties into account. Over the course of its shelf life, an anion solution standard undergoes stability testing to monitor the continued validity of its certified value. Currently, NIST offers seven anion standard solutions: bromide, chloride, fluoride, iodide, nitrate, phosphate, and sulfate. New lots of these SRMs produced continuously to meet demand and certificates of analysis are issued for each new lot to accurately reflect the anion mass fraction and associated uncertainty.

Citation

Special Publication (NIST SP) - 260-257

Report Number

260-257

NIST Pub Series

Special Publication (NIST SP)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.SP.260-257

Local Download

Keywords

Anions, Certified Value, Gravimetric Preparation, Ion Chromatography, Primary Standard (PS), Primary Standard Solution (PSS), Single Anion Standard Solution, Stability, Standard Reference Material (SRM), Traceability, Uncertainty.

Citation

Lang, B. , Vetter, T. , Molloy, J. and Possolo, A. (2025), Certification of 3180 Series Standard Reference Materials® Anions in Solution, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.SP.260-257, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=960290 (Accessed August 28, 2025)