Exploring the Use of Switchable Hydrophilicity Solvents as Extraction Phase for the Determination of Food-Packaging Contaminants in Coconut Water Samples by Gas Chromatography-Mass Spectrometry

This work proposes, for the first time, a method based on homogenous liquid-liquid microextraction with switchable hydrophilicity solvent as extraction phase (SHS-HLLME) for the determination of food-packaging contaminants including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di- n -octyl phthalate (DNOP), 4-octylphenol (4-OP), 4-nonylphenol (4-NP), and benzophenone (BZP) in coconut water samples by gas chromatography-mass spectrometry (GC-MS). Experimental parameters that can influence extraction efficiency, such as type and volume of SHS, sample volume, NaOH volume, temperature, and extraction time, were investigated. Using the optimal conditions, the calibration curves were linear from 0.5 to 30 μg L −1 for DMP and DEP; 1 to 30 μg L −1 for DBP, BBF, and DNOF; and 5 to 30 μg L −1 for BZP, 4-OP, and 4-NP. The coefficients of determination ranged from 0.9830 to 0.9972. The relative recoveries varied from 82 to 130%, and the intra- and inter-day precision values were lower than 18% for all analytes for the concentrations of 5, 15, and 30 μg L −1 . Limit of detection and quantification ranged from 0.15 to 1.51 μg L −1 and from 0.50 to 5.0 μg L −1 , respectively. In addition, the robustness of the methodology was examined and exhibited satisfactory results. Finally, the method developed was successfully applied for the analysis of six coconut water samples from food packaging. In this particular case, at least one analyte was found in five samples analyzed in the range of