Analysis of ethanol fuel according to standard methods using the Agilent 5100 SVDV ICP-OES

Significance of the topic

Bioethanol serves as a sustainable alternative to conventional fossil fuels, addressing concerns over resource depletion, environmental impact, and cost. Ensuring precise control of trace metal contaminants such as Cu, Fe, Na, and S in ethanol fuels is vital for engine performance, emissions control, and compliance with industry regulations.

Objectives and study overview

This work assesses the accuracy, precision, detection limits, calibration linearity, and long-term stability of the Agilent 5100 Synchronous Vertical Dual View (SVDV) ICP-OES for quantifying Cu, Fe, Na, and S in hydrated and anhydrous ethanol fuels according to ASTM D4806 and Brazilian ANP Resolution 19/2015.

Methodology and instrumentation

Samples of ethanol fuel were diluted tenfold with 1% HNO3 and analyzed on the Agilent 5100 SVDV ICP-OES equipped with a Dichroic Spectral Combiner. Key operating conditions included 1.50 kW RF power, 12 L/min plasma gas flow, 1.0 L/min auxiliary gas flow, 0.60 L/min nebulizer flow, and an 8 mm viewing height. Multi-element calibration standards in 10% ethanol covered 0–10 mg/L for Cu, 0–40 mg/L for Fe and Na, and 0–100 mg/L for S.

Main results and discussion

• Method detection limits were well below regulatory maximums (e.g., 0.003 mg/kg for Cu and Fe lines), ensuring sensitive quantitation.
• Calibration curves demonstrated excellent linearity (R² ≥ 0.99997) across all elements and wavelengths.
• Spike recovery experiments yielded 88–108% recoveries with relative standard deviations below 3.3%, meeting ASTM and ANP criteria.
• Over 150 minutes of continuous analysis, recoveries remained within ±10%, highlighting the instrument’s robustness and stability.

Benefits and practical applications of the method

• Simultaneous axial and radial detection accelerates throughput while maintaining sensitivity.
• Reduced argon consumption lowers operating costs compared to single-view systems.
• Robust organic sample handling prevents carbon buildup without requiring additional oxygen.
• Full compliance with industry standards supports quality control in biofuel production and regulatory reporting.

Future trends and opportunities

Advancements in plasma technology and dual-view optics will further enhance detection limits and sample throughput. Integration with automated sample preparation, coupling to separation techniques, and expanded multi-element capabilities will broaden applications in industrial analytics and support real-time monitoring of biofuel quality.

Conclusion

The Agilent 5100 SVDV ICP-OES effectively meets industry requirements for trace analysis of Cu, Fe, Na, and S in ethanol fuels. Its combination of accuracy, precision, stability, and efficient gas usage makes it a valuable asset for biofuel quality assurance and compliance workflows.

Reference

1. ASTM D4806 – Standard Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel, 2015.
2. ANP Resolution No. 19/2015 – Brazilian National Agency of Petroleum, Natural Gas and Biofuels, 2015.