CRM Nitrates (NO3-) - Aqueous calibration solution ASTASOL® AN90761HIC

Significance of Topic

Accurate quantification of nitrates is critical across environmental monitoring, food analysis and industrial QA/QC. Certified reference materials ensure reliable calibration of analytical instruments and comparability of results.

Objectives and Overview

The study details the certification of ASTASOL® AN90761HIC, an aqueous nitrate calibration solution. Key objectives include establishing accurate concentration, uncertainty and traceability to SI units, and demonstrating homogeneity and stability.

Methodology and Instrumentation

The CRM is prepared gravimetrically using high-purity NH4NO3, yielding direct traceability to the kilogram. Certified concentration and uncertainty were verified by independent gravimetric determination and comparison to NIST SRM 3185. Impurity profiling was performed by ion chromatography following membrane ultrafiltration at 0.45 µm.

Main Results and Discussion

The certified nitrate concentration is 1000 ± 2 mg/L (1001 ± 3 mg/kg) at 20 °C, with a density of 0.9994 ± 0.0005 g/cm³. Trace impurities of halides, nitrites, phosphates and sulfates were below detection limits (< 0.02–0.05 mg/L) and are provided for informational purposes only. Homogeneity and stability assessments confirm performance over a 5-year shelf life when stored between 5–30 °C.

Benefits and Practical Applications

ASTASOL® AN90761HIC supports calibration and validation of methods including AAS, AES, ICP-OES, ICP-MS, UV–Vis molecular absorption, ion chromatography and electroanalytical techniques. Its reliability enhances data quality in research and routine analysis.

Future Trends and Opportunities

Emerging directions include development of multi-analyte calibration solutions, microvolume CRMs, integration of digital certification and automated calibration systems, as well as expanding the range of matrices and analyte levels.

Conclusion

This certified nitrate solution offers well-defined traceability, uncertainty and long-term stability, fulfilling essential demands for high-precision analytical measurements.

References

• ISO Guide 31:2015, Reference materials — Contents of certificates.
• NIST SRM 3185, Nitrate in Water.