Preparation, optimization and application of poly(ethylene glycol)methyl ether methacrylate/urethane methacrylate as a new polar phase for stir bar sorptive extraction

The aim of this paper is to discuss the determination of carbaryl in a water sample using a stir bar sorptive extraction method based on a new polar extraction phase coupled with liquid desorption high performance liquid chromatography-diode array detection (SBSE-LD-HPLC-DAD). The process was conducted in an extraction medium mainly prepared from poly(ethylene glycol)methyl ether methacrylate (PEG-MMA) and urethane methacrylate (UMA). Polymerization of coating materials was performed under different conditions and the final hydrophilicity of the extraction medium was tuned by partial replacement of UMA with 2-hydroxy ethyl methacrylate (HEMA). The home-made polymethacrylate stir bars (PMA) showed good within batch repeatability (RSD < 6.4%) and batch-to-batch reproducibility (RSD < 8.5%). They could be reused at least 35 times for the extraction of carbaryl in a water sample with a minimum loss of extraction efficiency. The effects of the main parameters including desorption solvent and time, sample ionic strength, extraction time, sample volume and extraction temperature were studied in order to optimize the extraction performance of PMA stir bars. The linear dynamic range for the analysis of carbaryl was obtained in the range of 0.13–10 ng mL⁻¹ (R² = 0.9969). Furthermore, for this study, the limit of detection (LOD) and limit of quantification (LOQ) were obtained to be 0.04 and 0.13 ng mL⁻¹, respectively. The reproducibility of the method presented as intra- and inter-day precision was also found with the RSD less than 7.4%. The proposed method was successfully applied to the determination of carbaryl in a tap water sample. Moreover, the PMA coating manifested better extraction efficiency for carbaryl than the recently commercialized stir bars (polydimethylsiloxane and Acrylate Twisters®) due to the polar nature of this sorptive phase.