An automated and high-throughput approach for comprehensive analysis of biodiesel (B100) quality in compliance with EN and ASTM methods

Significance of the Topic

With growing interest in renewable fuels, ensuring the quality of pure biodiesel (B100) is critical for reliable engine performance and regulatory compliance. Key impurities such as glycerol, fatty acid methyl esters (FAMEs), and residual methanol must be monitored to prevent engine deposits, preserve material compatibility, and guarantee safe fuel handling.

Objectives and Study Overview

This work presents an automated, single-platform workflow for comprehensive biodiesel quality testing according to EN and ASTM standards. The goal is to streamline sample preparation, GC analysis of glycerol, FAMEs, and methanol, and data processing to achieve high throughput, minimized manual intervention, and consistent results.

Methodology and Instrumentation

• Multi-method GC approach using two Thermo Scientific TRACE 1610 systems in Clone Mode from a single TriPlus RSH SMART autosampler.
• Glycerol analysis: ASTM D6584 and EN 14105 with MSTFA derivatization and dual-syringe internal standard additions.
• FAME profiling: EN 14103 by GC-FID with automated ISTD spikes for total ester and linolenic methyl ester determinations.
• Methanol quantification: EN 14110 headspace-GC-FID with automated internal standard addition and hydrogen carrier gas with HeSafer-H2Safer safety system.
• Data management with Chromeleon CDS 7.3 for sequence setup, instrument control, and secure reporting compliant with FDA 21 CFR Part 11 and EU Annex 11.

Instrumentation Used

• TriPlus RSH SMART autosampler with Automatic Tool Change stations, vortex mixer, incubator, and headspace module
• Two TRACE 1610 GC-FIDs: one configured for free and total glycerol (PTV inlet) and one for FAMEs and methanol (dual SSL inlet)
• TraceGOLD TG-BIOD capillary column for glycerol and TRACE TR-BD columns for FAME and methanol separations
• Chromeleon 7.3 chromatography data system

Main Results and Discussion

Calibration curves for glycerol, glycerides, FAMEs, and methanol showed excellent linearity (r > 0.999). Automated workflows yielded sharp, well-resolved chromatograms with reduced run times. The Clone Mode configuration enabled simultaneous injections on two GC units, cutting analysis time by over 50% and maintaining precision through consistent sample handling and instrument parameters.

Benefits and Practical Applications

The automated platform reduces manual pipetting and exposure to toxic reagents, decreases cross-contamination risk, and frees analysts to focus on data interpretation. Laboratories can perform full biodiesel quality control—glycerol, FAMEs, and methanol tests—on a single system with unattended operation, enhancing productivity and data integrity.

Future Trends and Potential Applications

Advancements in autosampler robotics and data systems will further increase throughput and flexibility, enabling integration of additional analytical techniques such as mass spectrometry. Expanded automation may support real-time process monitoring and on-site fuel testing, driving wider adoption of sustainable biofuels.

Conclusion

The integrated automated workflow provides a reliable, high-throughput solution for comprehensive B100 quality analysis according to EN and ASTM standards. It ensures accurate, reproducible results while reducing analyst workload and improving laboratory efficiency.

Reference

• ASTM D6584 Standard Test Method for Determination of Total Monoglycerides, Diglycerides, Triglycerides, and Free and Total Glycerin in B100
• EN 14105 Fat and Oil Derivatives – Determination of Free and Total Glycerol and Glyceride Contents
• EN 14110 Fat and Oil Derivatives – Determination of Methanol Content
• EN 14103 Fat and Oil Derivatives – Determination of Ester and Linolenic Acid Methyl Ester Contents
• EN 14214 Liquid Petroleum Products – Fatty Acid Methyl Esters for Use in Diesel Engines – Requirements and Test Methods