Analysis of Gasolines by FT-IR Spectroscopy.

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Petroleum Science

Background:

• Traditional methods for determining gasoline properties are time-consuming and require large sample volumes.
• Simultaneous analysis of multiple fuel parameters is desirable for increased laboratory efficiency.

Purpose of the Study:

• To develop and validate a protocol for simultaneous determination of key gasoline properties using Fourier transform infrared (FT-IR) spectroscopy.
• To assess the efficiency, accuracy, and precision of the developed FT-IR method compared to standard analyses.

Main Methods:

• Established an experimental and computational protocol utilizing midband FT-IR spectroscopy.
• Applied multivariate calibration analysis to a single FT-IR spectrum for property estimation.
• Validated results against standard laboratory measurements for key gasoline properties.

Main Results:

• Simultaneous estimation of research/motor octane numbers, hydrocarbon content, benzene, ethanol, MTBE, and total oxygen achieved in ~1 minute with <2 mL sample.
• High correlation (R(2) = 0.94–0.99) between FT-IR-derived and standard laboratory values.
• Method precision comparable to standard analyses, with potential for >200-fold increase in laboratory output.

Conclusions:

• Midband FT-IR spectroscopy with multivariate calibration is a versatile, efficient, and accurate technique for simultaneous gasoline property analysis.
• The methodology significantly enhances petroleum laboratory throughput while minimizing sample, cost, and environmental impact.
• Further calibration with laboratory fuel blends may enable prediction of other oxygenated compounds and midrange boiling points.