CRM Copper (Cu) - Aqueous calibration solution ASTASOL® AN90151C

Significance of the Topic

A reliable certified reference material (CRM) for copper calibration in aqueous media is essential to ensure accuracy and traceability in various spectrometric and electroanalytical techniques. Such CRMs support quality control, method validation, and inter-laboratory comparability in environmental, industrial, and research laboratories.

Objectives and Study Overview

This certificate describes the preparation, characterization, and certification of ASTASOL® AN90151C, an aqueous calibration solution of copper at nominal concentration 1000 mg/L. The primary aims were:

• To establish a gravimetrically prepared solution traceable to the SI unit (kg).
• To verify concentration and uncertainty by independent analytical methods.
• To assess homogeneity, stability, and impurity profile.

Methodology and Instrumentation

The preparation followed a gravimetric protocol using high-purity copper metal (99.999%) dissolved in 2% HCl. Certification and verification employed:

• Complexometric titration referenced to SRM NIST 928.
• Simultaneous copper determination against SRM NIST 3114.
• Trace impurity screening by AAS, ICP-OES, and ICP-MS.

Used Instrumentation

• Atomic Absorption Spectrometry (AAS)
• Atomic Emission Spectrometry (AES)
• Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)
• Inductively Coupled Plasma Mass Spectrometry (ICP-MS)
• Complexometric Titrator

Main Results and Discussion

The certified copper concentration is 1000 ± 2 mg/L (expanded uncertainty, k=2) at 20 °C, corresponding to 994 ± 3 mg/kg by mass fraction. Trace impurities are below detection limits for most elements, ensuring negligible matrix effects. Homogeneity tests and stability studies confirm consistent performance over a five-year shelf life under recommended storage (5–30 °C).

Benefits and Practical Applications

The CRM supports calibration and validation of atomic spectrometry (AAS, AES, ICP-OES, ICP-MS), molecular absorption methods, and selected electroanalytical techniques. It enhances method accuracy, reduces systematic errors, and provides confidence in quantitative measurements across laboratories.

Future Trends and Opportunities

Advances in CRM development may include multi-element matrices, lower uncertainty targets, miniaturized sample formats, and digital traceability records. Emerging analytical platforms such as on-line process monitoring and portable field instruments will benefit from tailored calibration solutions.

Conclusion

ASTASOL® AN90151C offers a highly pure, gravimetrically traceable copper standard with rigorous verification and low impurity content. Its long shelf life, validated homogeneity, and broad analytical applicability make it a valuable tool for quality assurance in modern analytical chemistry.