Analysis of biodiesel conversion using thin layer chromatography and nonlinear calibration curves

Area of Science:

• Analytical Chemistry
• Green Chemistry
• Biotechnology

Background:

• Biodiesel (BD) production involves complex (trans)esterification reactions with multiple substrates.
• Accurate kinetic analysis requires extensive data, but traditional methods like gas chromatography (GC) and HPLC are time-consuming and costly.
• Existing chromatographic methods face challenges in separating and quantifying all reaction components simultaneously.

Purpose of the Study:

• To evaluate the applicability of thin layer chromatography (TLC) for analyzing biodiesel reaction mixtures.
• To develop and validate a quantitative TLC method for monitoring biodiesel synthesis.
• To compare TLC performance against established methods like GC and HPLC.

Main Methods:

• Thin layer chromatography (TLC) was employed for the separation and analysis of biodiesel components.
• Two detection methods were explored: flame ionization detector (FID) and a modified staining procedure.
• Quantitative analysis involved calibration and discussion of nonlinear response principles.

Main Results:

• The modified TLC staining method provided a clear, background-free profile suitable for quantitative analysis.
• Enzymatic conversion of rapeseed oil yielded high biodiesel conversion rates (85-95% in 6h, increasing to 97-98% after purification).
• TLC successfully separated and quantified all mixture components, with results correlating well to GC measurements (TLC-staining: 1.03±0.07; TLC-FID: 0.95±0.04).

Conclusions:

• Thin layer chromatography (TLC) is a viable, efficient, and cost-effective method for analyzing biodiesel reaction mixtures.
• The developed TLC staining procedure offers accurate quantitative analysis, simplifying kinetic studies of biodiesel production.
• TLC methods demonstrate strong applicability and reliability for monitoring biodiesel synthesis, complementing or replacing traditional techniques.