Quantitative Analysis of Copper Alloys and Differentiation of Sample Types by Matching Function

Significance of Topic

Energy dispersive X-ray fluorescence (EDXRF) analysis of copper alloys is essential for industries requiring rapid, non-destructive elemental quantification, such as metallurgical manufacturing, recycling, and quality assurance. The capacity to analyze complex alloy compositions with minimal sample preparation accelerates workflow and ensures compliance with material specifications.

Objectives and Overview

This application note evaluates the Shimadzu EDX-7200 spectrometer in two key areas: quantitative analysis of copper alloys via calibration curves, including accuracy, detection limits, and repeatability; and qualitative/quantitative identification of alloy types using fundamental parameter (FP) analysis combined with a matching search function.

Used Instrumentation

• Shimadzu EDX-7200 energy dispersive X-ray fluorescence spectrometer
• Silicon drift detector (SDD)
• Rhodium target X-ray tube (15 kV for light elements, 50 kV for heavier elements)
• Vacuum measurement atmosphere
• Collimators (1 mmφ and 10 mmφ) and element-specific primary filters
• Software enabling calibration curve generation, FP analysis, and library matching

Methodology

Quantitative calibration curves were prepared for ten elements (Cu, Pb, Fe, Sn, Zn, Al, Mn, Ni, P, Si) using certified copper alloy standards covering concentration ranges from sub-ppm to nearly pure metal. Absorption excitation (dj) and overlap (Ij) corrections were applied to account for matrix effects. Limits of detection (LOD) and quantitation (LOQ) were derived from theoretical reproducibility (3× and 10× standard deviation). Repeatability was assessed by ten consecutive measurements of an unknown alloy. FP analysis was conducted across the full element range (Na–U), and spectral results were compared to a preregistered library to rank sample similarity.

Main Results and Discussion

• Calibration curves exhibited linearity across broad concentration spans with standard deviation of error below 0.18 wt% for major elements and below 0.12 wt% for minors.
• LOD values ranged from approximately 0.0001 wt% (Ni) to 0.012 wt% (Zn); LOQs from 0.0003 wt% to 0.040 wt%.
• Repeatability tests showed coefficient of variation below 0.5% for elements above 1 wt% and 1–5% for trace elements (<1 wt%).
• The FP matching function correctly identified three test samples—phosphor bronze, brass, and nickel silver—by matching to known alloy libraries, even on small (≈2 mm) specimens.

Benefits and Practical Applications

• Compact footprint and no requirement for cooling water or extensive auxiliary equipment.
• Minimal sample preparation and flexibility in sample geometry.
• High quantitative accuracy suitable for production-line monitoring and incoming inspection of recycled materials.
• Rapid qualitative identification supports alloy sorting and authentication tasks.

Future Trends and Possibilities

Advances in detector technology and spectral algorithms are expected to further narrow detection limits and improve matrix correction capabilities. Integration of EDXRF with process automation and digital libraries will enhance real-time alloy analysis in manufacturing. Portable and in-line EDXRF systems may become standard tools for environmental monitoring, archaeological studies, and secondary resource management.

Conclusion

The Shimadzu EDX-7200 combines high analytical performance with operational simplicity, delivering accurate quantification and reliable alloy identification without extensive infrastructure. Its versatility positions it as a viable alternative to wavelength dispersive techniques in many industrial and research settings.

References

• Tamura, Y. Quantitative Analysis of Copper Alloys and Differentiation of Sample Types by Matching Function. Shimadzu Application News EDX-7200, First Edition Nov 2024.