TRM - Bi, Ge, In, 6Li, Lu, Rh, Sc, Tb - Aqueous calibration solution ASTASOL® ASTASOL® INT-MIX5

Importance of the Topic

Atomic spectrometry demands highly reliable calibration standards to achieve precise quantification of trace elements in aqueous samples. Certified reference materials with well-defined concentrations and uncertainties are essential for ensuring analytical accuracy and comparability across laboratories.

Study Objectives and Overview

This identification sheet details the preparation, characterization, and intended use of ASTASOL® INT-MIX5, a multielement aqueous calibration solution containing Bi, Ge, In, 6Li, Lu, Rh, Sc, and Tb. The document follows ISO Guide 31 requirements and outlines traceability, uncertainty assignment, and handling instructions.

Materials and Instrumentation

• Matrix composition: 10% v/v sub-boiling distilled HNO3 diluted with ultrapure demineralized water (resistivity ≥18 MΩ·cm), with trace HCl.
• Primary compounds: High-purity reagents (≥99.99%) including Bi, (NH4)2GeF6, In, 6Li, Lu2O3, (NH4)3RhCl6, Sc2O3, and Tb4O7.
• Preparation method: Gravimetric weighing under controlled conditions.
• Traceability: Calibration and comparison by AAS, AES, ICP-OES, and ICP-MS against NIST SRMs via an unbroken chain of calibrations using certified CRM AN series.

Main Results and Discussion

• Assigned concentration: 10.00 mg/L for each analyte with an expanded uncertainty of ±0.05 mg/L (k = 2) at 20 °C.
• Homogeneity and stability: Proven uniformity and stability over the one-year shelf life when stored at 5–30 °C in original closed bottles.
• Trace impurities: Total impurity level below 0.02 mg/L, confirming matrix integrity for trace analysis.

Benefits and Practical Applications

• Suitable calibrator for a range of analytical techniques including AAS, AES, ICP-OES, ICP-MS, molecular absorption, and selected electroanalytical methods.
• Supports quality assurance and method validation in industrial, environmental, and research laboratories.
• Ensures compliance with ISO/IEC 17025 and ISO 9001 standards for reference material usage in QA/QC workflows.

Future Trends and Opportunities

• Expansion of multielement solutions to include additional emerging trace analytes relevant to environmental and clinical applications.
• Integration with automated calibration systems and real-time verification procedures to streamline analytical workflows.
• Advancements in uncertainty quantification and stability testing methods to meet increasingly stringent regulatory requirements.

Conclusion

ASTASOL® INT-MIX5 delivers a rigorously characterized, traceably prepared multielement standard with low impurity levels and demonstrated stability. It is an invaluable tool for achieving reliable and reproducible trace element measurements across various spectrometric platforms.

References

1. ISO Guide 31: Reference Materials — Contents of Certificates and Labels
2. ISO/IEC 17034:2016: General Requirements for the Competence of Reference Material Producers
3. NIST Standard Reference Materials for Elemental Analysis