Ultrasound Assistant Deep-Eutectic-Solvent-Based Liquid–Liquid Microextraction for the Determination of Transesterification Catalyst in Biodiesel Samples

• Published in: Theoretical foundations of chemical engineering Vol. 57; no. 1; pp. 104 - 111
• Main Authors: Shishov, A. Yu, Markova, U. O., Nizov, E. R., Melesova, M. A., Meshcheva, D. A., Krekhova, F. M., Bulatov, A. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.02.2023; Springer Nature B.V
• Subjects: Alkaline earth metals; Analytical chemistry; Atomizing; Biodiesel fuels; Carboxylic acids; Catalysts; Chemistry; Chemistry and Materials Science; Eutectics; Fatty acids; Hydroxides; Industrial Chemistry/Chemical Engineering; Magnesium; Mass transfer; Quaternary ammonium salts; Solvents; Transesterification; Triglycerides; Ultrasonic imaging; flame atomization atomic absorption spectrometry; deep eutectic solvent; ultrasound assistant dispersive liquid–liquid microextraction; transesterification catalysts; biodiesel
• ISSN: 0040-5795; 1608-3431
• DOI: 10.1134/S004057952301013X

Hydroxides of alkali and alkaline earth metals are most widely used as catalysts for transesterification of triglycerides of fatty acids in biodiesel production. After biodiesel purification, the determination of catalyst residue is performed to prevent their excess accumulation. Catalysts can promote the degradation of biodiesel. In this research, a simple, fast, and environmentally friendly strategy for the sensitive determination of transesterification catalysts (sodium, potassium, calcium, and magnesium) in biodiesel samples by flame atomization atomic absorption spectrometry is developed. The developed procedure is based on ultrasound assistant dispersive liquid–liquid microextraction of the catalysts in a hydrophilic deep eutectic solvent prepared by mixing quaternary ammonium salt and carboxylic acid. The effect of the nature of the deep eutectic solvent on the mass transfer of catalysts is investigated; in addition, the microextraction procedure conditions are optimized to obtain high sensitivity. The limits of detection established for the proposed procedure are 0.03 mg kg –1 for all analytes. No hazardous and volatile organic solvents are required for sample pretreatment. Sample preparation time is less 15 min.