Analysis of Traces in Aqueous Solutions with Thermo Scientific ARL PERFORM’X Advanced WDXRF Spectrometer

Significance of the Topic

The presence of trace heavy metals and toxic elements in water sources poses significant environmental and health risks. Accurate detection at low concentrations is essential for regulatory compliance and environmental monitoring.

Objectives and Study Overview

This study evaluates the performance of the Thermo Scientific ARL PERFORM’X advanced WDXRF spectrometer for quantifying trace elements in aqueous solutions. Key goals include:

• Establishing calibration curves for target elements at 2–100 ppm
• Determining limits of detection with a 100 s counting time
• Demonstrating operational stability and ease of use

Used Instrumentation

The analysis employed the Thermo Scientific ARL PERFORM’X sequential WDXRF spectrometer configured as follows:

• 2500 W Rhodium X-ray tube with 50 µm Be window
• Six primary beam filters and four collimators
• Up to nine analyzing crystals and two detectors (scintillation and flow proportional counters)
• Helium purge system with LoadSafe Ultra protective features
• OXSAS WDXRF software under Windows® 10

Methodology

Samples were prepared by diluting 1000 ppm standards to concentrations of 2, 5, 10, and 100 ppm. Measurements were conducted at 60 kV and 41 mA in a helium-purged primary chamber, using selected crystal-detector-collimator combinations. Overlap suppression for Cd was achieved via a primary beam filter.

Main Results and Discussion

Calibration yielded limits of detection (LoD) ranging from 0.2 ppm (Cu, Ni, Zn) to 1.1 ppm (As, Cd) in 100 seconds:

• As Kβ: 1.1 ppm
• Ba Lα: 0.9 ppm
• Cd Kα: 1.1 ppm
• Co Kα: 0.3 ppm
• Cu Kα: 0.2 ppm
• Hg Lα: 0.6 ppm
• Ni Kα: 0.2 ppm
• Pb Lβ: 0.4 ppm
• Zn Kα: 0.2 ppm

A representative scan confirmed effective detection of trace Hg and As. Stability tests demonstrated consistent performance month after month due to the low current filament and efficient power management.

Benefits and Practical Applications

• Minimal sample preparation without external water cooling
• Rapid vacuum-to-helium exchange for consistent analytical repeatability
• Enhanced safety features including liquid cassette recognition and auto-eject
• Suitable for wastewater, industrial effluent, and environmental monitoring

Future Trends and Opportunities

Advances in detector technology and software integration can further lower detection limits and streamline workflows. Helium consumption optimization and expanded element coverage will support emerging regulatory requirements and broaden applications in quality control and research.

Conclusion

The ARL PERFORM’X spectrometer offers a reliable, high-sensitivity solution for trace element analysis in aqueous matrices. Its robust design, ease of use, and competitive detection limits make it an effective tool for environmental and industrial monitoring.

Reference

Thermo Fisher Scientific Inc. AN41677 Application Note, Analysis of Traces in Aqueous Solutions with Thermo Scientific ARL PERFORM’X Advanced WDXRF Spectrometer, 2017.