Agilent 4500 and 5500 FTIR Biodiesel Analyzers

Importance of the Topic

Ensuring the quality and stability of biodiesel blends is critical for engine performance, regulatory compliance and environmental sustainability. Long‐term storage of biodiesel can encourage microbial growth and oxidative degradation, while improper blend levels can damage engine components designed for petroleum diesel. Rapid, reliable measurement of fatty acid methyl esters (FAME) in diesel fuels is therefore essential for quality control in laboratories and field operations.

Objectives and Study Overview

The study describes the design and performance of Agilent’s portable 4500 and 5500 FTIR Biodiesel Analyzers, highlighting their ability to:

• Quantify biodiesel concentration in diesel fuel according to ASTM D7371 and EN 14078
• Detect low‐level contamination and mixing errors
• Operate in laboratory or field environments without specialized training

Methodology and Instrumentation

The analyzers employ Fourier Transform Infrared (FTIR) spectroscopy with transmission sampling interfaces optimized for liquid fuels. Key features include:

• TumblIR™ and DialPath™ liquid cells for reduced maintenance
• Pre-loaded calibration models covering biodiesel ranges of 0.025–1%, 1–10% and 10–20% FAME
• Factory testing and method calibration for out-of-the-box operation

Main Results and Discussion

Performance metrics for the three calibration ranges demonstrate excellent precision and accuracy:

• 0.025–1% FAME: SECV 0.0016%, R² 0.9999, average relative error 1.37%
• 1–10% FAME: SECV 0.0164%, R² 0.9999, average relative error 0.06%
• 10–20% FAME: SECV 0.04%, R² 0.9999, average relative error 0.57%

The overlaid IR spectra show clear absorbance differences at the ester carbonyl region (around 1740 cm⁻¹) even at ultra‐low biodiesel levels, confirming the method’s sensitivity.

Practical Benefits and Applications

These portable FTIR systems enable rapid, on‐site verification of biodiesel content, reducing downtime and sample transport delays. Industries can enforce blend specifications, prevent equipment failure and meet regulatory standards efficiently.

Future Trends and Potential Applications

Advancements may include expanded fuel parameter panels (e.g., water content, oxidation products), automated data reporting, and integration with digital quality management systems. Custom calibration kits for emerging biofuel feedstocks will further enhance versatility.

Conclusion

Agilent’s 4500 and 5500 FTIR Biodiesel Analyzers offer a robust, user-friendly solution for precise quantification of biodiesel in diesel fuel. Their factory-configured methods and portable design support flexible deployment, ensuring reliable quality control in diverse settings.

Reference

• Agilent Technologies, Inc. Agilent 4500 and 5500 FTIR Biodiesel Analyzers Application Note, 2012.