CRM Chromium (Cr) - Aqueous calibration solution ASTASOL® AN8013N

Significance of the Topic

Accurate determination of trace metals in aqueous matrices is fundamental for environmental monitoring, industrial quality control and research applications. Certified reference materials (CRMs) serve as indispensable benchmarks for calibration, method validation and establishing metrological traceability, thereby enhancing confidence in analytical results.

Objectives and Study Overview

The aim of this certification is to present ASTASOL AN8013N, an aqueous chromium calibration solution, with a defined concentration and associated uncertainty. The study outlines the production, characterization, homogeneity and stability assessment of the CRM to support a wide range of spectrometric and electroanalytical techniques.

Methodology and Instrumentation

The CRM was prepared gravimetrically using high-purity Cr(NO3)3·9H2O and premixed in 2% sub-boiled HNO3 with ultrapure water. Key steps included:

• Traceability to the kilogram via gravimetric preparation.
• Verification of certified chromium concentration by ICP-OES and comparison with SRM NIST 3112a.
• Assessment of trace impurities using AAS, ICP-OES and ICP-MS for informational purposes.
• Homogeneity and stability studies conducted over the defined shelf life.

Main Results and Discussion

The certified chromium concentration is 100.0 mg/L with an expanded uncertainty of ±0.2 mg/L (k = 2) at 20 °C, corresponding to 99.2 mg/kg (±0.3 mg/kg). The solution density is 1.0078 g/cm3 (±0.0005 g/cm3). Trace impurities were detected at sub-µg/L levels or below detection limits, confirming high purity. Stability and homogeneity tests demonstrate consistent performance over a five-year shelf life under recommended storage conditions.

Benefits and Practical Applications

ASTASOL AN8013N provides a reliable chromium standard for calibration and validation of atomic spectrometry (AAS, AES, ICP-OES, ICP-MS), molecular absorption and selected electroanalytical methods. Its direct SI traceability and low uncertainty support rigorous quality assurance and interlaboratory comparisons.

Future Trends and Opportunities

Development of multi-element CRMs with even lower uncertainties and broader concentration ranges is anticipated. Advances in microfluidic calibration systems and digital certification formats will further streamline analytical workflows and data integrity.

Conclusion

ASTASOL AN8013N represents a high-quality CRM ensuring traceable and precise chromium calibration in aqueous analysis. Its rigorous characterization and validated stability make it suitable for diverse analytical platforms.

Instrumentation Used

• Gravimetric balance for solution preparation
• ICP-OES for concentration verification
• ICP-MS and AAS for impurity profiling