DETAILED INFORMATION ABOUT THE PRODUCTION OF AQUEOUS CALIBRATION SOLUTIONS ASTASOL®

Significance of Topic

Aqueous calibration solutions such as ASTASOL® are essential reference materials for ensuring accuracy and traceability in quantitative analysis across atomic spectrometry (AAS, AFS, ICP-OES, ICP-MS), molecular absorption spectrometry, ion chromatography and selected electroanalytical methods. They underpin quality assurance in environmental monitoring, industrial process control and research laboratories by providing certified concentration values for single or multi-element solutions.

Objectives and Study Overview

This document details the production, quality assurance and certification procedures for ASTASOL® aqueous calibration reference materials. It covers raw material selection, preparation protocols, homogeneity and stability testing, value assignment and uncertainty estimation, as well as packaging and storage guidelines aligned with ISO 17034, ISO Guide 35 and related standards.

Methodology and Instrumentation

Primary substances consist of high-purity metals or stoichiometric compounds (>99.95 %) supplied under ISO 17034 QA systems and verified by accredited laboratories. Sub-boiling distilled acids, ultrapure reagents and 18 MΩ·cm deionised water are used. Mass determination is performed on Class 1 electromechanical analytical balances calibrated by national metrology institutes, using F1 class weights. Temperature is monitored with calibrated mercury or alcohol thermometers (0–50 °C, 0.1 °C division). Volume measurements employ Class 1 flasks, pipettes and burettes certified by manufacturers and regularly checked.

Used Instrumentation

• Class 1 analytical balances with internal F1 weight checks
• Mercury and alcohol thermometers (0–50 °C, 0.1 °C divisions)
• Class 1 volumetric flasks, pipettes and burettes
• ICP-OES, ICP-MS and AAS systems for impurity verification
• Gravimetric and titrimetric setups for primary value assignment

Main Results and Discussion

ASTASOL® solutions exhibit excellent homogeneity due to their dilute nature; ANOVA-based testing confirms uniformity. Long-term stability is supported by over 20 years of experience and targeted tests for evaporation, adsorption/desorption, precipitation and accelerated thermal conditions (–20 °C to +40 °C). Certified values are assigned by gravimetric preparation referenced to primary substances and are not recalculated from verification data. Typical expanded uncertainties (k = 2) are approximately 0.2 % for certified values and 0.5 % for assigned values, validated by both primary and instrumental methods.

Benefits and Practical Applications

High-quality, SI-traceable calibration solutions enable laboratories to achieve consistent quantification, satisfy regulatory requirements and maintain accreditation (ISO 9001, ISO 17025). They support method validation, instrument calibration and inter-laboratory comparisons, improving reliability in environmental, clinical, pharmaceutical and industrial analyses.

Future Trends and Potential Applications

Emerging directions include automated CRM production, micro-volume and on-demand formulations, blockchain-based digital certificates, eco-friendly reagents and expanded matrices (e.g., organic solvents). Multi-element mixtures tailored for advanced hyphenated techniques and nanomaterial suspensions are anticipated to meet evolving analytical challenges.

Conclusion

The well-controlled production and certification workflow for ASTASOL® aqueous calibration solutions ensures traceable, reliable standards with low uncertainty and proven stability. Compliance with international guidelines and rigorous verification protocols delivers robust tools for high-precision analysis across diverse scientific and industrial fields.

References

1. Moody R, Grenberg RR, Pratt KW, Rains TC. Anal. Chem. 60(21):1203A (1988)
2. Clement RE, Keith LH, Michael Sin KW, eds. Reference Materials for Environmental Analysis. CRC Press, 1997.
3. ISO 17034: General Requirements for the Competence of Reference Material Producers.
4. ISO Guide 31: Reference Materials – Contents of Certificates and Labels.
5. CORM ČMI Directive 017-MP-C001-06: Preparation and Certification of Reference Materials, 2006.
6. ISO Guide 35: Certification of Reference Materials – General and Statistical Principles.
7. Eurachem. Determination of Uncertainty in Analytical Measurement. Kvalimetrie 11, 2001.
8. ISO Guide to the Expression of Uncertainty in Measurement, 1993.
9. Vlasák M, Luxemburková Z, Sychra V, Suchánek M. Accred. Qual. Assur. 18:491 (2013).
10. ČSN EN ISO 9001: Quality Management Systems – Requirements.
11. ČSN EN ISO/IEC 17025: General Requirements for the Competence of Testing and Calibration Laboratories.
12. ČSN EN ISO 17034: General Requirements for the Competence of Reference Material Producers.