Analysis of Sulfur in Petroleum Products According to ASTM D4294 & ISO 8754 using Shimadzu’s EDX-7000

Significance of the Topic

Sulfur in petroleum fuels generates sulfur dioxide and other oxides during combustion, contributing to respiratory health issues and acid rain. Regulatory bodies worldwide, including the IMO, have imposed stringent sulfur limits in marine and transportation fuels to curb atmospheric SOx emissions.

Objectives and Study Overview

This study evaluates Shimadzu’s EDX-7000 energy-dispersive X-ray fluorescence spectrometer for determining total sulfur in petroleum products according to ASTM D4294 and ISO 8754. The goal was to verify compliance with repeatability, reproducibility, and detection limit requirements under both ambient and helium-purged conditions.

Methodology and Instrumentation Used

The method followed ASTM D4294 and ISO 8754 protocols, employing 5 µm polypropylene sample films. Measurements were performed at room temperature (25 °C) and ~50 % RH, with the instrument warmed up for at least 15 minutes. Sulfur fluorescence was measured under air or helium atmospheres, using integration times of 100–300 s dependent on concentration. Repeatability and reproducibility were assessed over 20 replicates and across different instruments and operators. Detection limits were calculated using standard blank analyses.

Main Results and Discussion

• Repeatability (RSD) met ASTM D4294 criteria at ≥500 ppm sulfur in air and ≥50 ppm with helium purge, achieving RSDs below 0.3 % at higher concentrations.
• Reproducibility complied at ≥500 ppm in both atmospheres, with RSDs below 0.5 % for base oil and 1.85 % for diesel.
• For ISO 8754, the EDX-7000 satisfied repeatability and reproducibility across 0.03–4 wt % sulfur under ambient conditions, with RSDs under 1.3 %.
• Blank analyses yielded a maximum of 1.9 ppm sulfur. Calculated lower limits of detection were 2.49 ppm (He-purged) and 5.61 ppm (air), well below upcoming 5000 ppm regulatory requirements.
• Calibration curves displayed high linearity, ensuring accurate quantitation across the tested range.

Benefits and Practical Applications of the Method

The EDX-7000 offers rapid, non-destructive sulfur analysis with minimal sample preparation. Helium purge allows lower detection limits, while ambient operation simplifies routine QA/QC workflows. Analysis times can be halved at concentrations ≥500 ppm without compromising precision, supporting high-throughput testing in industrial and regulatory laboratories.

Future Trends and Applications

Emerging needs for even lower sulfur detection and real-time monitoring may drive integration of EDXRF into automated online systems. Advances in portable XRF instruments and chemometric calibration models could extend field applications for compliance checks and environmental screening. Strengthening global sulfur regulations will further elevate demand for fast, accurate XRF-based sulfur analysis.

Conclusion

Shimadzu’s EDX-7000 energy-dispersive XRF spectrometer reliably meets ASTM D4294 and ISO 8754 requirements for sulfur determination in petroleum products. It delivers high precision, low detection limits, and flexible operating conditions, making it a valuable tool for laboratories facing increasingly stringent sulfur regulations.