Quantitative analysis of free glycerol in biodiesel using solid-phase extraction and high-performance liquid chromatography

• Published in: Microchemical journal Vol. 168; p. 106347
• Main Authors: de Almeida Cozendey, Daniel, de Oliveira Muniz, Renan, Cavalcante dos Santos, Rafael, Gimenes de Souza, Cristiane, França de Andrade, Débora, Antonio d'Avila, Luiz
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2021
• Subjects: Biodiesel; Free glycerol; High-performance liquid chromatography; Solid-phase extraction; High-performance liquid chromatography; Free glycerol; Biodiesel; Solid-phase extraction
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2021.106347

[Display omitted] •Application of liquid chromatography for analysis of free glycerol in biodiesel.•Estimation of errors and quantitative parameters for partial validation of the method.•Comparison of analytical performance between the proposed and the reference method. This study developed a method for separating and quantifying free glycerol in biodiesel. The free glycerol in biodiesel samples was separated using solid-phase extraction (SPE) and subsequently quantified by high-performance liquid chromatography (HPLC) using an ion-exchange stationary phase and refractive index detector (IR). The proposed method (SPE-HPLC-IR) was validated for high- and low-concentration samples (coefficient of determination, R2≥0.99): limit of detection (0.00029% m/m, high; 0.00018% m/m, low); limit of quantification (0.00089% m/m, high; 0.00054% m/m, low); precision (standard deviation < 5.0%), and accuracy (recovery of 98.93% to 106.71%). The proposed method was compared with the reference method (ASTM D6584) using the paired t-test, and no statistical differences were found between them (95% confidence). As such, the proposed method offers a simple, quick, effective method for determining free glycerol in biodiesel and a viable alternative to the reference method.