CRM Zinc (Zn) - Aqueous calibration solution ASTASOL® ANS069

Significance of the Topic

Certified reference materials for aqueous calibration solutions play a crucial role in ensuring accurate and traceable quantitative measurements across environmental, pharmaceutical, and industrial laboratories. A well-characterized zinc standard supports reliable method validation in atomic spectrometry, molecular absorption spectrometry, and electroanalytic techniques.

Objectives and Overview

This document certifies ASTASOL® ANS069, an aqueous CRM containing zinc at 1000 ± 5 mg/L (k = 2) at 20 °C. It describes the material’s production, certification process, intended applications, and handling requirements for calibration and validation of analytical procedures.

Methodology and Instrumentation

The CRM preparation followed a gravimetric procedure using 99.998 % Zn dissolved in 2 % (v/v) sub-boiled HNO₃ and ultrapure water (≥ 18 MΩ·cm). Traceability to the SI unit kilogram was established through direct gravimetric measurements. Verification of the assigned concentration and uncertainty employed:

• Complexometric titration against SRM NIST 928.
• Atomic absorption spectrometry (AAS).
• Atomic emission spectrometry (AES).
• Inductively coupled plasma optical emission spectrometry (ICP-OES) using CRM AN90691N.

Applied Instrumentation

• High-precision analytical balance for gravimetric preparation.
• Titrator system for complexometric analysis.
• AAS, AES, and ICP-OES instruments for concentration verification.

Main Results and Discussion

The certified zinc concentration is 1000 ± 5 mg/L (k = 2). Total trace impurities in the solution remain below 0.5 mg/L. Homogeneity and long-term stability tests confirm the material’s consistency over its five-year shelf life when stored at 5–30 °C under sealed conditions. Users must equilibrate the solution to 20 ± 0.5 °C before use and avoid contamination by following strict handling instructions.

Benefits and Practical Applications

ASTASOL® ANS069 serves as a primary calibration standard for:

• Atomic spectrometric methods (AAS, AES, ICP-OES).
• Molecular absorption spectrometry.
• Selected electroanalytical techniques targeting zinc quantification.

Future Trends and Possibilities

Emerging directions include multi-element CRMs, reduction of sample volumes through microfluidic formats, and integration of digital certificates with laboratory information management systems for seamless traceability, enhanced data integrity, and automated compliance reporting.

Conclusion

ASTASOL® ANS069 offers a robust, SI-traceable zinc calibration solution with certified concentration and stability parameters. It underpins precise analytical measurements and quality assurance workflows in diverse laboratory settings.