CRM Fluorides (F-) - Aqueous calibration solution ASTASOL® AN90731H

Significance of the topic

Analytical calibration standards ensure precise quantification of analytes in environmental and industrial contexts. Fluoride monitoring is critical for water quality assessment, health diagnostics, and regulatory compliance. High-purity, SI-traceable reference solutions enhance inter-laboratory comparability and method accuracy.

Objectives and Overview

This certificate outlines the properties, preparation, and performance of ASTASOL AN90731H, an aqueous fluoride calibration solution. It aims to demonstrate measurement traceability, value assignment, homogeneity, and stability in line with ISO Guide 31 recommendations.

Methodology

Preparation of the solution involves gravimetric dissolution of sodium fluoride (NaF, 99.99% purity) in ultrapure demineralized water at 20 °C. Certified values are assigned through complexometric titration traceable to NIST SRM 928. Density measurement (1.0012 ± 0.0005 g/cm3) enables conversion between mass fraction and concentration.

Used Instrumentation

• Complexometric titration equipment calibrated with NIST SRM 928
• Atomic absorption spectrometer (AAS)
• Inductively coupled plasma optical emission spectrometer (ICP-OES)
• Inductively coupled plasma mass spectrometer (ICP-MS)

Main Results and Discussion

The certified fluoride concentration is 1000 ± 2 mg/L (expanded uncertainty k=2) at 20 °C, equivalent to 999 ± 3 mg/kg mass fraction. Trace impurity levels for Br-, Cl-, I-, NO2-, NO3-, PO43-, and SO42- are below detection limits (<0.02–<0.05 mg/L). Homogeneity and stability tests confirm uniformity across batches and shelf life of five years unopened, with 12 months validity after first opening.

Benefits and Practical Applications

The CRM is suitable for calibration and validation of AAS, AES, ICP-OES, ICP-MS, molecular absorption spectrometry, and selected electrochemical techniques. Its high purity and low impurity background support accurate environmental, pharmaceutical, and industrial analyses.

Future Trends and Opportunities

Future developments may include multi-analyte calibration solutions, integration of digital certificates for improved traceability, and novel packaging formats to enhance stability and ease of use. Advances in automated handling and miniaturized delivery systems could further streamline calibration workflows.

Conclusion

ASTASOL AN90731H meets ISO Guide 31 criteria, providing a reliable, SI-traceable fluoride standard with validated homogeneity and stability. Its broad applicability enhances quality assurance across diverse analytical platforms.

Reference

Analytika, spol. s r.o. Certificate for Aqueous Calibration Solution ASTASOL® AN90731H, Version 01, June 9, 2023.