Green and Efficient Determination of Iron(III) in Gasoline Using Microemulsion-Based Extraction and Digital Image...

Area of Science:

• Analytical Chemistry
• Green Chemistry
• Materials Science

Background:

• Iron(III) contamination in gasoline degrades fuel quality and engine performance.
• Conventional methods for iron analysis are reliable but require complex equipment and extensive sample preparation.
• Accurate iron monitoring is crucial for fuel stability and engine longevity.

Purpose of the Study:

• To develop a sustainable and innovative method for determining iron contamination in gasoline.
• To combine extraction induced by microemulsion breaking (EIMB) with digital image analysis (DIA) for iron determination.
• To align analytical methodologies with Green Chemistry principles for fuel analysis.

Main Methods:

• Utilized naturally present ethanol in Brazilian gasoline to form microemulsions without surfactants.
• Optimized experimental conditions using a 2^4 factorial design, identifying isopropanol as a dispersing agent, 1.0 mol L-1 HCl, 8 min extraction, and 500 μL breaking volume.
• Employed smartphone-based digital image analysis (DIA) for quantification.

Main Results:

• Achieved a linear range of 0.3-10 mg L-1 and a detection limit of 0.3 mg L-1 for iron determination.
• Demonstrated method reliability through recovery tests on spiked gasoline samples, with recovery rates between 97.4% and 116.2%.
• Successfully formed microemulsions without surfactants, simplifying the procedure and reducing reagent consumption.

Conclusions:

• The proposed EIMB-DIA strategy offers a sustainable, low-cost, and accessible analytical method for iron in gasoline.
• This approach minimizes reagent use and eliminates toxic surfactants, adhering to Green Chemistry principles.
• Represents a significant advancement in sustainable analytical techniques for complex fuel matrices.