Analysis of Ni and V in diesel fuel oils with ARL PERFORM’X XRF Series

Significance of the Topic

Corrosive species such as vanadium and nickel in diesel fuel oils can severely degrade engine components, leading to higher maintenance costs and unexpected downtime.
Trace analysis of these metals is critical for quality control and regulatory compliance in marine, power generation, and industrial sectors.

Objectives and Overview of the Study

This study aims to develop a fast and robust WDXRF method for direct determination of nickel and vanadium at sub ppm levels in diesel fuel oils.
The method is intended for routine process and quality control applications, meeting or exceeding international standards for example ISO 14597.

Methodology and Instrumentation

• Sample preparation: 10 g of each diesel standard filled into a liquid cell with 6 micron polypropylene film.
• Atmosphere: helium purge to minimize air absorption and scatter.
• Measurement: Thermo Scientific ARL PERFORMX WDXRF spectrometer (4200 W X-ray tube, Rh anode, six primary beam filters, nine crystals, two detectors).
• Instrument features: LoadSafe sample loading, liquid cassette recognition, Secutainer powder containment, helium shutter for goniometer protection.
• Analytical conditions for each element:
  - Vanadium Kalpha with LIF200 crystal and fast primary beam filter, 150 s counting time.
  - Nickel Kalpha with LIF200 crystal and strip collimator filter, 150 s counting time.

Main Results and Discussion

• Calibration: linear response without matrix correction, standard error of estimate of 0.020 ppm for vanadium and 0.025 ppm for nickel.
• Limits of detection: 0.076 ppm for vanadium, 0.028 ppm for nickel at recommended counting times.
• Precision: repeatability study with four liquid cells yielded an average nickel concentration of 1.7 ppm (RSD 3.1 percent).

Benefits and Practical Applications

• Rapid and straightforward sample handling with minimal preparation.
• Multi-element capability allows simultaneous determination of critical trace metals.
• High sensitivity and precision ensure compliance with stringent fuel specifications such as sub ppm limits.
• Enhanced laboratory throughput supports routine quality assurance and process control.

Future Trends and Applications

• Integration of automated sample changers for high throughput analysis.
• Expansion to other fuel types and petrochemical matrices.
• Further miniaturization of XRF instrumentation for field and on site monitoring.
• Advanced data analytics and AI driven calibration models for improved accuracy.

Conclusion

The ARL PERFORMX WDXRF system demonstrates excellent sensitivity, accuracy, and precision for trace analysis of vanadium and nickel in diesel fuels. Its robust design and streamlined workflow make it ideal for routine compliance testing and preventive maintenance programs in diverse industrial settings.