CRM Chlorides (Cl-) - Aqueous calibration solution ASTASOL® ANS272

Significance of the Topic

Aqueous chloride calibration solutions are essential reference materials for ensuring accuracy and traceability in quantitative analysis across environmental, industrial, and regulatory laboratories. Certified reference materials (CRMs) like ASTASOL ANS272 provide a benchmark for method validation, instrument calibration, and quality control procedures, reducing uncertainty and enabling comparability of results across labs.

Objective and Overview

This document certifies the production and properties of ASTASOL ANS272, a high-purity aqueous chloride solution at an assigned concentration of 10 000 mg/L ± 50 mg/L (k=2) in ultra-pure water. Prepared by Analytika, spol. s r.o., it aims to offer a stable, traceable calibration standard compliant with ISO Guide 31 and accredited according to ISO 17034.

Methodology and Instrumentation

The certification process involved:

• Gravimetric preparation ensuring direct SI traceability to kilogram.
• Verification of concentration and uncertainty by acidimetric titration.
• Independent confirmation using ion chromatography (IC) with a short, unbroken calibration chain to CRM AN90691N.

Used Instrumentation

• Analytical balance for gravimetric preparation.
• Acidimetric titration apparatus.
• Ion chromatograph for chloride determination.

Main Results and Discussion

The certified CRM exhibits:

• Assigned chloride concentration of 10 000 mg/L with an expanded uncertainty of 0.5 % (k=2) at 20 °C.
• Trace impurities below 5 mg/L total, supporting high analytical selectivity.
• Demonstrated homogeneity across production batches and guaranteed stability over a five-year shelf life when stored between 5 °C and 30 °C.

The short traceability chain and dual analytical verification methods reinforce the robustness of the certification.

Benefits and Practical Applications

ASTASOL ANS272 supports:

• Calibration and validation of chloride analysis methods in aqueous matrices.
• Quality control in atomic spectrometry (AAS, AES), molecular absorption spectrometry, and electroanalytical techniques.
• Enhanced comparability of routine and research data across laboratories.

Future Trends and Application Possibilities

Emerging analytical demands in environmental monitoring, process control, and food safety will drive further development of certified multi-element solutions and low-level trace CRMs. Coupling CRMs with advanced hyphenated techniques (e.g., IC-MS) can extend their applicability and improve detection limits.

Conclusion

ASTASOL ANS272 represents a rigorously certified chloride calibration solution with well-defined uncertainty, SI traceability, and robust stability. Its application ensures reliable analytical performance and supports regulatory compliance and research accuracy worldwide.