Sampling and Sampling Containers as the Foundation for Reliable Water Analyses

Importance of the Topic

Proper water sampling and container selection are essential steps to ensure accurate and reliable analytical data for environmental management, public health, and industrial processes.

Objectives and Overview of the Study

This white paper reviews critical factors in the sampling process, including container materials, preservation techniques, and handling procedures, based on current standards and ALS practices.

Methodology and Instrumentation

• Standards: EN ISO 5667-3:2024 for water sampling, preservation, and handling.
• Sampling Containers: Single-use containers tested for stability (volumes: 40, 60, 100 mL) made of certified plastic or glass.
• Chemical Preservation: Use of pre-loaded fixatives to stabilize target analytes without rinsing.
• Physical Preservation: Transport at 2–8 °C in darkness using insulated ALS bags and electric vans.

Key Results and Discussion

• Container Material Impact: Processes such as adsorption, contamination, oxidation, and biological activity can alter analyte concentrations (e.g., metals, pesticides, TOC, BTEX, ammonia).
• Stability Study: Ammonium ion levels remain stable for over 14 days in chemically preserved samples, while unpreserved samples degrade significantly within 48 hours.
• Quality Assurance: Regular batch testing of sampling containers ensures consistency and detects manufacturing-related changes.

Benefits and Practical Applications

• Improved data accuracy and reproducibility across environmental analyses.
• Extended sample stability reduces the urgency of laboratory processing and minimizes false negatives.
• Compliance with international standards enhances laboratory accreditation and stakeholder confidence.

Future Trends and Potential Applications

Emerging developments include in situ sensor-based preservation, eco-friendly container materials, and digital tracking of chain-of-custody to further enhance sampling reliability and traceability.

Conclusion

Reliable water analysis depends on rigorous adherence to standardized sampling protocols, careful selection of container materials, and effective preservation methods to safeguard sample integrity and support informed decision-making.

References

• ISO 5667-3:2024 Water quality — Sampling — Part 3: Preservation and handling of water samples.