Eco-friendly miniaturized kapok-fiber supported liquid-phase extraction coupled with gas chromatography-flame ionization detector for high-throughput edible oil preparation and low-cost determination of synthetic antioxidants

Abstract

The addition of synthetic phenolic antioxidants can effectively delay or prevent oxidation of edible oils. However, excessive use of these antioxidants can have negative impacts, which emphasizes the importance of accurate analysis methods to determine their presence in edible oils. Given the large number of food samples involved in regulatory purposes, there is a need to develop high-throughput and cost-effective detection methods for routine analysis. However, the existing methods are not suitable, indicating a need for further improvement. This study presents a technique that combines miniaturized-kapok fiber-supported liquid-phase extraction (mini-KF-SLE) with gas chromatography-flame ionization detection (GC-FID) to determine synthetic antioxidants like 3-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxytoluene, and tert-butylhydroquinone in edible oils. The mini-KF-SLE device consists of 20mg of kapok fibers placed in a 1mL pipette tip attached to a pipette. The extraction procedure involves three simple steps: loading the oil sample (150mg), adding the extractant (150µL of ACN), and eluting the extractant by applying air pressure using a pipette. The developed mini-KF-SLE-GC-FID method shows satisfactory quantitation ability (R2>0.99) and detection limits of 0.4–0.5µg/g. Moreover, the relative standard deviations for all analytes were below 9.2%, indicating good precise of the method for routine analysis. The proposed method also exhibits excellent environmental friendliness, as evidenced by three widely recognized metrics. Overall, the mini-KF-SLE-GC-FID method provides a convenient, low-cost, environmentally friendly, and easy to automate alternative for routinely determining synthetic antioxidants in edible oils.