Evaluation of an analytical method for determining phthalate esters in wine samples by solid-phase extraction and gas chromatography coupled with ion-trap mass spectrometer detector

A solid-phase extraction (SPE) method was developed for extraction and analysis of six phthalate esters in wine samples using Carbograph 1 sorbent. The SPE procedure allowed efficient recovery of the investigated phthalates ranging between 78% and 105% with a relative standard deviation (RSD) ≤6.5 for an ethanolic phthalic acid ester (PAE) standard solution and between 73-71% and 96-99% with a RSD ≤8.4 for red wine samples spiked with 20 and 50 ng mL -1 of PAE, respectively. The adsorption isotherms and breakthrough curves for Carbograph 1/water solution were reported. Gas chromatography coupled with an ion-trap mass spectrometer detector (GC/IT-MS) was used for analysis. The instrumental analytical protocol was found to yield a linear calibration in the range 0.01-10.0 μg mL -1 with R 2 values ≥0.9992. The limits of detection in GC/IT-MS (SIM mode) vary between 0.2 and 14 ng mL -1 (RSD ≤5.6) whereas the limits of quantification range between 0.5 and 25 ng mL -1 (RSD ≤5.9); the intra- and inter-day repeatabilities calculated as RSD for wine samples, were between 0.9-7.8 and 1.0-10.5, respectively. The analytical method developed was applied to several commercial wine samples. Furthermore, the investigated methods are simple, reliable, reproducible, and not expensive.