Evaluation of Phthalic Acid Esters in Fish Samples Using Gas Chromatography Tandem Mass Spectrometry with Simplified QuEChERS Technique

Phthalic acid esters (PAEs) have become an important food safety concern due to their lipophilic properties and propensity to accumulate in adipose tissue in edible fish. In this study, a simple, sensitive, and accurate analytical method was successfully established for simultaneous determination of 19 PAEs in fish samples using gas chromatography coupled with tandem mass spectrometry (GC–MS/MS). A simplified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure was applied for sample preparation, and the Plackett-Burman factorial design was utilized for optimizing extraction parameters. The calibration curves were linear in the range 0.01–0.5 mg/kg for all of the analyzed PAEs, and the limits of quantification (LOQs) were 0.05–20 μg/kg which are much lower than those in previous reports. The average spiked recoveries ranged from 71.2 to 116.3%, with relative standard deviations (RSDs) of 3.9 to 16.2% (n = 6). Finally, the method was applied to analyze 60 real fish samples taken from Shanghai Municipality, China, and the diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), and bis(2-ethoxyethyl)phthalate (DEHP) were found in almost all fish samples tested in this study. The present study demonstrated that the established method was suitable for market surveillance of 19 PAE residues in fish samples.