Halogens in a polymer sample applying Metrohm Combustion IC according to IEC 60754

Significance of the topic

The Restriction of Hazardous Substances Directive (RoHS) mandates reduction of halogenated compounds in polymers used for electrical and electronic equipment. Analytical confirmation of halogen content is vital for compliance, safety and material selection. Combustion ion chromatography (Combustion IC) with flame sensor technology and inline matrix suppression provides a robust approach to quantify chloride and bromide in polymer matrices according to IEC 60754.

Study Objectives and Overview

This study demonstrates an analytical workflow for determining halogen levels in a polymer sample with up to 1% halogen content. The goal is to achieve precise quantification of chloride and bromide while suppressing matrix interferences, thereby meeting industry standards for routine quality control and regulatory compliance.

Methodology and Workflow

The polymer sample is combusted in an oxygen-argon stream at 1050 °C using flame sensor technology. Combustion gases are absorbed in a hydrogen peroxide solution and introduced into the ion chromatograph via Partial-Loop Injection (MiPT) with Inline Matrix Elimination. An anion exchange column separates halide ions, which are then detected by a conductivity detector after sequential suppression.

Used Instrumentation

• 881 Compact IC pro – Anion – MCS (2.881.0030)*
• IC Conductivity Detector (2.850.9010)*
• 920 Absorber Module (2.920.0010)*
• Combustion Module (2.136.0700)*
• Autosampler MMS 5000 (2.136.0800)*
• Kit for solid samples (6.7302.000)*
• Metrosep® A Supp 5 – 150/4.0 (6.1006.520)
• Metrosep® A Supp 4/5 Guard/4.0 (6.1006.500)
• Metrosep® A PCC 1 HC/4.0 (6.1006.310)

* Combustion IC configuration: 881 Metrohm Combustion IC (2.881.3030)

Main Results and Discussion

• Chloride concentration: 0.6 g/kg, RSD 6.8 % (n=3)
• Bromide concentration: 10.3 g/kg, RSD 4.1 % (n=3)
• Sulfate: not quantified under these conditions

The results show adequate precision and sensitivity for halogen analysis in polymers. Inline matrix elimination minimizes background noise and potential interferences, enhancing the method’s robustness for complex solid samples.

Benefits and Practical Applications

• Ensures compliance with RoHS and IEC 60754 standards
• Requires minimal sample preparation
• Delivers reliable quantification of halogen levels in polymeric materials
• Suitable for routine quality control in manufacturing and research laboratories

Future Trends and Potential Applications

Advances in combustion IC may focus on further automation, integration with mass spectrometry for speciation, and reduction of detection limits to trace levels. Expanding the method to encompass fluorine analysis and other regulatory analytes could broaden its utility across environmental and materials science sectors.

Conclusion

Combustion ion chromatography with flame sensor detection and inline matrix elimination offers a powerful and compliant approach for determining halogen content in polymers. The method provides sufficient accuracy, repeatability and throughput for industrial and regulatory applications.