Tin in Resin Analysis Using EDX - Sn Screening Analysis Kit

Importance of the Topic

The use of organotin compounds in industrial and consumer applications has been widespread due to their properties as stabilizers, catalysts, antifouling agents, and preservatives. However, growing concerns over the toxicity of certain organotin species have led to strict regulations such as the EU’s REACH Annex XVII. As a result, rapid and reliable screening methods for elemental tin (Sn) in resin matrices are in high demand to ensure regulatory compliance and protect human health and the environment.

Objectives and Study Overview

This study demonstrates the workflow and performance of a tin screening analysis kit for the Shimadzu EDX-7200 energy dispersive X-ray fluorescence spectrometer, using PCEDX-Navi software. The primary aim is to enable non-specialist operators to quickly assess total Sn levels in polyvinyl chloride (PVC) and polyethylene (PE) resin samples to flag materials that require further compound-specific analysis.

Methodology and Instrumentation

Energy dispersive X-ray fluorescence (EDX) was employed under the following conditions:

• Instrument: Shimadzu EDX-7200
• Detector: Silicon drift detector (SDD)
• X-ray tube: Rhodium target, 50 kV
• Collimator: 10 mm diameter
• Primary filter: #1
• Atmosphere: Air
• Integration time: 100 seconds per sample
• Dead time: Up to 30%

Used Instrumentation

The analysis kit includes:

• EDX-7200 spectrometer
• PCEDX-Navi control and evaluation software
• Sn-containing polyethylene control sample
• Threshold settings for Sn, RoHS elements (Cd, Pb, Cr, Hg, Br), Cl, and Sb

Main Results and Discussion

PVC resin samples doped with Sn were measured in four replicates side by side, with ten repeated measurements in total. Key findings include:

• Mean Sn concentration: 1,641.7 ppm
• Standard deviation: 20.3 ppm
• Coefficient of variation: 1.2%
• Limits of detection: 3.4 ppm in PE resin and 5.7 ppm in PVC resin under screening conditions

The PCEDX-Navi software automatically shifts measurement conditions based on preset thresholds, improving throughput by eliminating unnecessary measurement time for samples well above or below limits.

Benefits and Practical Applications

The screening kit offers:

• Comprehensive analysis of Sn alongside regulated RoHS elements, Cl, and Sb in a single run
• Turnkey solution with control samples and user-friendly software
• Automated judgment (OK/??/ND) and report generation, suitable for QA/QC and routine screening labs

Future Trends and Potential Applications

Advancements may include:

• Integration of AI-driven data analysis for enhanced decision support
• Expanded screening protocols for additional regulated elements and matrices
• Improved detection limits via optimized detectors or vacuum measurement modes
• Seamless coupling with compound-specific techniques (e.g., GC/MS) for confirmatory analysis

Conclusion

The Shimadzu EDX-7200 Sn screening analysis kit provides a robust, user-friendly platform for rapid elemental tin screening in resin materials. Its high throughput, reliable detection limits, and integrated software make it an ideal tool for laboratories requiring efficient compliance testing under REACH and related regulations.

References

1) European Chemicals Agency. REACH Regulation Annex XVII: Substances Restricted Under REACH. ECHA website.