Determination of Chemical Species in Marine Fuel Oil in Accordance with ASTM D 7845

Importance of the Topic

Marine fuel oils contain a diverse range of aromatic and oxygenated compounds that influence environmental emissions, combustion efficiency, and regulatory compliance. Accurate profiling of these species is critical for ensuring fuel quality, reducing pollutant formation, and meeting international standards.

Objectives and Study Overview

This work describes the development and validation of a GC–MS method for the determination of thirty target chemical species in marine fuel oil according to ASTM D7845. The primary goal is to achieve reliable separation, identification, and quantification of aromatic hydrocarbons, phenols, styrenes, and related oxygenates in a single analytical run.

Methodology and Instrumentation

The analytical system is based on a Shimadzu GCMS-QP2020 NX coupled with an AOC-20i Plus autosampler.

• Injection: Programmable Temperature Vaporization (PTV) at 0.5 µL
• Column Setup: Two-dimensional separation using SH-1 (30 m × 0.25 mm I.D., 0.25 µm) and SH-5MS (60 m × 0.32 mm I.D., 0.5 µm) columns connected by a restrictor
• Carrier Gas: Helium under pressure control (260 kPa initial, ramp to 400 kPa)
• Temperature Program: 50 °C (2 min), 7 °C/min to 200 °C; then 200 °C to 400 °C at 200 °C/min
• Detection: Dual MS/FID with high-concentration tuning; scan and SIM in FASST mode for sensitive quantification
• Flow Rates: Total 35 mL/min, split ~25 mL/min to columns; FID makeup gases optimized for hydrogen, air, and makeup flow

This configuration targets compounds ranging from light alcohols and ethers to heavier phenols and phenoxy derivatives.

Main Results and Discussion

The total ion chromatogram shows baseline separation of all 30 analytes within a 30-minute run. Early-eluting alcohols and ethers appear before 5 minutes, while aromatic phenols and styrenes elute between 10 and 25 minutes. Dual MS/FID detection enhances confidence in peak identification and quantification. Retention times and peak shapes remained consistent across replicates, supporting the method’s robustness under both scan and SIM acquisition modes.

Benefits and Practical Applications

• Meets ASTM D7845 requirements for marine fuel analysis
• Enables routine monitoring of environmentally relevant fuel constituents
• Dual detection (MS/FID) provides both structural confirmation and quantitation
• Applicable to quality assurance in shipping, petrochemical, and environmental laboratories

Future Trends and Potential Applications

Future enhancements may include high-throughput automation, coupling with high-resolution mass spectrometry for greater specificity, and expanding the analyte scope to emerging fuel contaminants. Portable or field-deployable GC–MS units could facilitate on-site fuel quality assessment and environmental screening.

Conclusion

The presented GC–MS method offers a comprehensive and reproducible approach for analyzing a wide range of aromatic and oxygenated species in marine fuel oils. Compliance with ASTM D7845 and the dual-column, dual-detector setup ensures high analytical performance for routine and regulatory applications.

Reference

Shimadzu Corporation. Application News M304A, First Edition: September 2022, ERAS-1000-0391