An Effervescence-assisted Centrifuge-less Dispersive Liquid-Phase Microextraction Based on Solidification of Switchable Hydrophilicity Solvents for Detection of Alkylphenols in Drinks

Abstract

Abstract A simple, efficient and environmentally-friendly pretreatment technique was proposed for determination of alkylphenols (4-tert-octylphenol, nonylphenol and octylphenol) in drink samples using high performance liquid chromatography-fluorescence detection. In this approach, the extractants in the form of (green) medium-chain fatty acids were generated in situ in the Pasteur pipette and extractant droplets dispersed by CO2 generated by an effervescent reaction. A demulsifier was then used to break up the emulsion and induce phase separation, thus avoiding the need for a time-consuming centrifugation step. Finally, the floating extractant droplets were collected through solidification. Under optimal conditions, a good linearity was obtained in the concentration range from 0.1 μg/mL to 10 μg/mL, with determination coefficients ranging from 0.997 to 0.999. The extraction recoveries varied from 75.8% to 94.4% and the limits of quantification were in the range of 1.55–2.30 μg/L. The developed approach had good prospects in detection of alkylphenols in mineral water, tea drink, carbonated drink and Baijiu.