Analysis of phthalates with IEC standard method using non-deactivated stainless steel sample cups

Significance of the Topic

Phthalates are key plasticizers regulated under RoHS and other safety standards for their potential health and environmental risks. Reliable quantification in polymer matrices is essential for quality control and compliance.

Objectives and Study Overview

This study evaluates the performance of non-deactivated stainless steel sample cups against the standard deactivated cups in the IEC 62321-8 TD-GC/MS method for phthalate analysis. A certified PVC standard containing eight phthalates and an adipate was analyzed in quadruplicate with each cup type.

Methodology

Freeze-ground PVC samples (~0.5 mg) were loaded into both deactivated and cleaned non-deactivated cups. Thermal desorption was performed from 200 °C to 340 °C, followed by GC/MS analysis using a dimethylpolysiloxane column under split injection.

Instrumentation Used

• Multi-Shot Pyrolyzer (EGA/PY-3030D)
• Auto-Shot Sampler
• Vent-free GC/MS adapter
• UA-PBDE column (15 m × 0.25 mm i.d., 0.05 µm)
• Eco-Cup LF and RoHS cup LN stainless steel cups

Main Results and Discussion

Thermal desorption chromatograms from both cup types were virtually identical. Peak area RSDs were ≤4% for all phthalates. Relative recoveries ranged from 94% to 101% relative to deactivated cups, indicating no significant catalytic effects or loss of analytes with non-deactivated cups.

Practical Benefits and Applications

Disposable non-deactivated cups offer cost savings, eliminate cross-contamination risk, and simplify sample preparation, without compromising data quality in phthalate screening and regulatory compliance testing.

Future Trends and Applications

Single-use stainless steel cups could be extended to other additive or contaminant analyses in polymers. Further research may explore alternative surface treatments, high-throughput platforms, and broader regulatory contexts.

Conclusion

Non-deactivated stainless steel sample cups, when cleaned and used according to IEC 62321-8 guidelines, deliver equivalent precision and accuracy for phthalate analysis compared to standard deactivated cups, streamlining workflows and reducing costs.