TOC Analysis for Evaluation of Plastics and Other Organic Materials in Contact with Drinking Water

Significance of TOC Analysis in Drinking Water Contact Materials

Ensuring that materials in contact with drinking water do not release harmful organic compounds is critical for public health and regulatory compliance. Total Organic Carbon (TOC) analysis provides a sensitive measure of organic leachables from plastics, coatings and other components specified under the EU Drinking Water Directive (EU) 2020/2184.

Objectives and Study Overview

This application note evaluates the performance of the Shimadzu TOC-L Analyzer for determining TOC in migration waters produced from plastic hoses and other organic materials. The goals are to demonstrate compliance testing workflows, validate measurement precision across multiple migration periods, and support certification of hygienic suitability.

Methodology and Sample Preparation

Migration waters are generated according to EN 12873-1 and EN 12873-2 by:

• Rinsing specimens for 60 minutes at 23 °C.
• Stagnation with fresh water for 24 hours.
• Repeated three consecutive migration periods (72 h at 23 °C or 24 h at 60–85 °C).

After each period, water is collected for TOC analysis. Sample acidification and degassing are performed automatically by the TOC-L system before measurement.

Used Instrumentation

• Shimadzu TOC-L CPH Analyzer
• High Sensitivity Platinum Catalyst
• Automatic Sample Injector ASI-L

Main Results and Discussion

TOC measurements on hose migration waters showed:

• 1st period TOC: 0.72 mg/L NPOC
• 2nd period TOC: < 0.5 mg/L NPOC
• 3rd period TOC: < 0.5 mg/L NPOC

These low TOC values confirm minimal organic extractables and support compliance with EU limits.

Benefits and Practical Applications

TOC-L offers:

• Rapid, automated analysis for routine quality control.
• Wide dynamic range (0.25–5 mg/L) via multi-point calibration and automatic dilution.
• Support for certification bodies verifying hygienic suitability under ISO/IEC 17065.

Future Trends and Potential Uses

Emerging directions include integration of TOC analysis with mass spectrometric screening for unidentified organics, miniaturized field-deployable TOC units for on-site compliance, and combining TOC data with microbial growth assays to assess biofilm risks.

Conclusion

The Shimadzu TOC-L system provides a robust, compliant solution for evaluating organic leachables from materials in contact with drinking water. Its automation and sensitivity streamline certification workflows, safeguarding water quality and public health.

References

• European Union Drinking Water Directive (EU) 2020/2184, Article 11.
• EN 12873-1 and EN 12873-2: Migration testing of materials in contact with drinking water.
• Shimadzu Application Note 05-SCA-130-406-EN, First Edition Nov. 2024.