Determination of hazardous substances according to RoHS

Importance of the Topic

The Restriction of Hazardous Substances (RoHS) directive and rigorous quality control in food and water analysis are critical for environmental protection and public health. Reliable detection of regulated elements in electronics and monitoring of contaminants in consumables ensure compliance with legal limits and safeguard consumers.

Objectives and Overview

• Establish a routine, non-destructive method for RoHS compliance testing of electronic components using energy-dispersive X-ray fluorescence.
• Demonstrate direct sample placement and flexible system configuration for rapid screening.
• Review spectroscopic techniques for identifying and quantifying trace contaminants in food and drinking water.

Methodology

• Energy-dispersive X-ray fluorescence (EDXRF) analysis with the Shimadzu EDX-700HS instrument.
• UV-VIS spectrometry (UVmini-1240) for hexavalent chromium detection.
• FTIR spectrometry (IRPrestige-21) and GC-MS (GCMS-QP2010) for brominated flame retardant analysis.
• Atomic absorption spectrometry (AA-6800) with flame and graphite furnace atomization for trace metal determination.

Used Instrumentation

• Shimadzu EDX-700HS energy-dispersive X-ray fluorescence spectrometer
• UVmini-1240 UV-VIS spectrometer
• UV-2401PC UV-VIS spectrophotometer
• IRPrestige-21 FTIR spectrometer
• GCMS-QP2010 gas chromatograph–mass spectrometer
• AA-6800 atomic absorption spectrometer with deuterium and high speed self reversal background compensation

Main Results and Discussion

• EDXRF provided reliable detection of RoHS-regulated elements (Pb, Cd, Hg, Cr(VI), brominated retardants) at threshold levels (e.g., 100 mg/kg Cd, 1000 mg/kg Pb).
• Method detection limits reached 0.1 mg/L for Cd by flame AAS and 0.1 µg/L by graphite furnace AAS.
• Analytical performance depended on sample matrix and instrument parameter settings.
• Complementary spectroscopic methods enabled sensitive quantitation of trace and ultra-trace elements in aqueous and organic samples.

Benefits and Practical Applications

• Non-destructive, rapid screening of electronic parts for RoHS compliance.
• Direct sample positioning accelerates analysis throughput.
• Versatile spectrometers support diverse QA/QC tasks in environmental and food laboratories.
• Combination of multiple techniques enhances accuracy in trace-level determinations.

Future Trends and Opportunities

• Automation and integration of sample handling for higher throughput and reproducibility.
• Enhanced detector materials and optics to lower detection limits further.
• Development of extensive spectral libraries for food contaminant identification.
• Growing regulatory demands will drive adoption of multi-element, multi-technique analytical platforms.

Conclusion

Energy-dispersive X-ray fluorescence and complementary spectroscopic methods form robust toolsets for RoHS compliance and contaminant monitoring in food and water. These approaches support regulatory adherence, environmental protection, and consumer safety by providing reliable, non-destructive, and sensitive analysis.

Reference

1. Robertson C. A case study of energy-dispersive X-ray fluorescence as a tool for RoHS compliance analysis. Presented at IPC/JEDEC 7th International Conference on Lead-Free Electronic Components and Assemblies, Frankfurt, Germany, October 2004.