TRM - Bi, Ge, In, 6Li, Lu, Rh, Sc, Tb - Aqueous calibration solution ASTASOL® ASTASOL® INT-MIX4

Importance of the Topic

Reliable calibration standards are fundamental in analytical chemistry to ensure accurate quantification of trace elements. Multi­element solutions like ASTASOL® INT-MIX4 support diverse techniques (AAS, AES, ICP-OES, ICP-MS, molecular absorption, electroanalytical) used across environmental monitoring, clinical testing, industrial quality control and research laboratories.

Objectives and Overview of the Sheet

This identification sheet defines the properties, preparation, traceability and handling instructions for ASTASOL® INT-MIX4, a reference material containing eight elements (Bi, Ge, In, 6Li, Lu, Rh, Sc, Tb) each at 100 mg/L. It complies with ISO Guide 31 specifications to guarantee consistent performance as a calibration solution.

Used Methodology and Instrumentation

The solution is prepared gravimetrically from high-purity primary compounds (purity ≥99.99 %) dissolved in 10 % HNO3 with trace HCl, using sub-boiled distilled acid and ultrapure water (≥18 MΩ·cm, 0.22 µm filtered). Concentration assignment and expanded uncertainty (±0.5 mg/L, k=2 at 20 °C) are based on traceable calibrations and comparisons via AAS, AES, ICP-OES and primary analytical methods linked to NIST SRMs.

Key Results and Discussion

ASTASOL® INT-MIX4 exhibits:

• Assigned concentration 100.0 ± 0.5 mg/L for each analyte at 20 °C.
• Trace impurities below 0.2 mg/L total.
• Demonstrated homogeneity across the batch and stability over the shelf life (produced 11-08-2022; expiry 11-08-2024) when stored at 5–30 °C.

Critical handling steps include equilibrating to 20 ± 0.5 °C before use, sealing the bottle neck with parafilm after opening and avoiding pipetting or returning aliquots.

Benefits and Practical Applications

ASTASOL® INT-MIX4 offers:

• High accuracy and low uncertainty for multi-element calibration.
• Direct applicability in various spectrometric and electrochemical methods.
• Short traceability chain ensuring comparability with international standards.
• Ease of use with clear handling and storage guidelines.

Future Trends and Potential Applications

Advances in miniaturized and automated analytical platforms will benefit from stable multi-element CRMs. Future developments may include custom mixtures tailored to emerging contaminants, integration in high-throughput workflows and expansion into novel detection techniques such as portable spectrometers and lab-on-a-chip systems.

Conclusion

ASTASOL® INT-MIX4 is a robust, traceable calibration solution that enhances the reliability of trace element determinations across multiple analytical techniques. Its certified concentration, proven homogeneity and stability support stringent quality assurance requirements in modern laboratories.

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)

References

• ISO Guide 31: Reference Materials – Contents of Certificates and Labels
• ISO 9001:2016 – Quality Management Systems
• ISO 17034:2017 – Competence of Reference Material Producers