Dados do Trabalho

Título

Determination of TBHQ in soybean oil using reverse-phase dispersive liquid-liquid microextraction by FIA system

Introdução

Palm, soybean, canola and sunflower oils represents 88% of global production in 2022/23 season. The main problem is the oxidation of oils, that affects sensory analyses. Using antioxidants, as tert-butylhydroquinone (TBHQ), is the simplest way to reduce this problem. On the other hand, when consumed in high doses for long periods, this additive can cause carcinogenic effects, which is why Brazilian legislation allows the addition of 200 mg kg-1 of TBHQ to oils. The oil matrix is very complex to analyze, and the use of fast and efficient preparation methods has become increasingly popular, such as reversed-phase dispersive liquid-liquid microextraction (DLLME). Antioxidants are determined by chromatography, a high-cost technique that requires a high consumption of reagents and a long analysis time. Amperometric techniques have great advantages due to their low cost and fast quantification. When coupled to the flow injection system (FIA), they perform with high sensitivity and precision in the analyses. Therefore, this study focuses on the development of a new method for the determination of TBHQ in soybean oil using a DLLME analyzed by the FIA system.

Material e Métodos

For the analysis, 1 mL of soybean oil and 2 mL of Triton X-100 extractant (30 mmol L-1) were used. The mixture was subjected to vigorous stirring in a vortex mixer for 60 seconds to promote the formation of a microemulsion and partition of the analyte into the aqueous phase. The microemulsion was broken and the phase was separated by centrifugation at 3800 RPM for 10 min. Then, an aliquot of the rich phase was removed and stored for analysis in FIA with a printed electrode, KCl supporting electrolyte (0.01 mol L-1) and amperometric detector.

Resultados e Discussão

Sample preparation was optimized in terms of oil and extractant ratio, extractant type, extractant concentration and vortex time.The optimal condition chosen was described, obtaining 100% extraction. The determination of analytical parameters was obtained in the range of 10 to 1300 µmol L-1 with detection limits of 5 µmol L-1.

Conclusão

In additional, the proposed method demonstrated great potential in the determination of TBHQ in soybean oil.