Development and validation of stir bar sorptive extraction of polar phenols in water followed by HPLC separation in poly(vinylpyrrolididone-divinylbenzene) monolith

An effective and simple method for polar phenols in water matrix was developed by using stir bar sorptive extraction (SBSE) based on a hydrophilic poly(vinylpyrrolididone-divinylbenzene) (VPDB) monolithic material and HPLC analysis. To achieve optimum extraction performance for phenols, several parameters, including extraction and desorption time, desorption solvent, pH value, and ionic strength of sample matrix, were investigated. Under the optimized experimental conditions, eight phenols were directly enriched from water samples and analyzed by HPLC-DAD. The detection limits (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target compounds were achieved within the range of 0.72-1.37 and 2.40-4.27 ng/mL from spiked water, respectively. Recoveries of eight phenolic compounds were found in the range of 55.2-95.9%. The calibration curves showed the linearity ranging from 5 to 150 ng/mL with linear regression coefficient R-2 values above 0.98. Method repeatability presented as intra- and interday precisions were also found with the RSDs less than 4.10 and 7.61%, respectively. The distribution coefficients between VPDB and water (K-VPDB/W) for phenolic compounds were also calculated and compared with K-O/W. Finally, the proposed method was successfully applied to the determination of the target compounds in tap water, sea water and wastewater samples.