CRM Chlorides (Cl-) - Aqueous calibration solution ASTASOL® AN8072H

Significance of the topic

Certified reference materials play a central role in ensuring the reliability, comparability and traceability of analytical results. A well-characterized aqueous chloride standard underpins accurate quantitation in environmental, pharmaceutical, food and industrial analyses, supporting routine quality control and method validation.

Objectives and overview of the study

This document presents the certification of ASTASOL® AN8072H, an aqueous calibration solution for chloride (Cl–). It aims to provide users with a fully traceable, homogeneous and stable reference material with a certified chloride concentration and associated uncertainty, suitable for a variety of analytical techniques.

Methodology and instrumentation

The chloride solution was prepared gravimetrically using high-purity potassium chloride (KCl, 99.997 %) dissolved in ultrapure water to achieve SI traceability. The certified concentration and its expanded uncertainty (k = 2) were confirmed by argentometric titration. Trace impurities were assessed by ion chromatography to inform users of potential interferences.

Used instrumentation

• Analytical balance for gravimetric preparations
• Titration system for argentometric verification
• Ion chromatograph for trace impurity screening
• Temperature-controlled bath to maintain 20 ± 0.5 °C during measurement

Key results and discussion

The certified chloride concentration is 100.0 mg/L with an expanded uncertainty of 0.2 mg/L at 20 °C. The solution density (0.9999 g/cm3 ± 0.0005) enables conversion to mass fraction (100.0 mg/kg ± 0.3 mg/kg). All common anionic impurities (Br–, F–, I–, NO2–, NO3–, PO43–, SO42–) were below detectable limits, demonstrating high purity. Homogeneity testing confirmed uniform chloride content across the batch, and stability studies validate the 5-year shelf life under recommended storage conditions.

Benefits and practical applications

• Provides SI-traceable calibration for atomic absorption/emission (AAS/AES), ICP-OES/MS and molecular absorption spectrometry
• Supports ion chromatography and electrochemical methods
• Enhances quality assurance, method validation and interlaboratory comparability

Future trends and potential applications

Advances in digital certification and blockchain-linked traceability may further streamline CRM management. Expanding the portfolio to include multielement or matrix-matched standards can address emerging analytical challenges in complex sample matrices.

Conclusion

ASTASOL® AN8072H delivers a rigorously characterized, stable and user-friendly chloride reference solution. Its high purity, full SI traceability and broad applicability make it a cornerstone for accurate chloride quantitation across diverse analytical platforms.

Reference

Certified according to ISO Guide 31 and produced under ISO 17034:2017. Quality management: ISO 9001:2016, ISO/IEC 17025:2018.