Fabric Phase Sorptive Extraction Prior to HPLC–DAD Determination of Monomers Released from Dental Resin Composites in Dental Wastewater

A novel fabric phase sorptive extraction method (FPSE) was developed for the detection of monomers released during dental restorative procedures, which are subsequently discharged into the environment through dental unit drainage systems. The presence of Bisphenol-A (BPA), Triethylene glycol dimethacrylate (TEGDMA), Urethane dimethacrylate (UDMA) and Bisphenol A-glycidyl methacrylate (Bis-GMA), released from dental resin composites in dental wastewater, was monitored using high-performance liquid chromatography coupled to diode array analysis (HPLC–DAD). FPSE was optimized with respect to the following significant parameters: (a) membrane type, (b) membrane size, (c) extraction time, (d) stirring during extraction, (e) sample volume, (f) ionic strength, (g) elution solvent, (h) elution time, and (i) agitation during elution. For HPLC–DAD analysis, the mobile phase constituted of acetonitrile–water, and a gradient elution program was followed. The detection was carried out at 220 nm. The method was validated in terms of linearity, sensitivity, selectivity, accuracy, and precision, showing satisfactory results. The limits of detection (LOD) and quantification (LOQ) were equal to 0.015 ng/μL and 0.05 ng/μL, respectively, for BPA, TEGDMA, and Bis-GMA, and 0.04 ng/μL and 0.13 ng/μL, respectively, for UDMA. The method demonstrated satisfactory precision, with relative standard deviation (RSD) values lower than 7.7% for intra-day and lower than 9.5% for inter-day studies. Relative recoveries ranged from 93.9% to 100.8% (intra-day) and from 92.0% to 101.7% (inter-day) for all target analytes. The developed FPSE–HPLC–DAD method was applied to the filtered/dissolved fraction of a real dental wastewater sample after centrifugation and filtration.