Determination of haloacetic acids in swimming pool waters by membrane-protected micro-solid phase extraction

• Application of micro-solid phase extraction for the determination of haloacetic acids in swimming pool water.
• Porous silica was prepared from rice husk ash and then functionalized with Fe via sol–gel process.
• The method is simple, fast, has satisfactory precision and accuracy.

In this study, a simple and efficient extraction method for determining haloacetic acids (HAAs) in swimming pool waters has been developed. HAAs are toxic organic pollutants of disinfection origin most commonly detected in swimming pool and drinking waters at trace level concentrations. For the first time, a highly efficient sorbent was developed using rice husk and used for micro-solid phase extraction (μ-SPE) technique. To increase the extraction capability of rice husk silica, iron oxide was incorporated via sol–gel process. In μ-SPE device, the novel sorbent was packed and used for extraction of HAAs prior to analysis using ultra performance liquid chromatography–ultraviolet detection (UPLC–UV). Various extraction parameters were optimized to improve the extraction efficiency of μ-SPE. Under optimum conditions, linearity (coefficient of determination, r2 ≥ 0.991 over the concentration range of 1–150 μg/L), detection limits in the range of 0.001–0.092 μg/L, mean recoveries up to 110% with corresponding relative standard deviations of 2–7% (n = 3) had been obtained. Finally, the method was applied to swimming pool water to evaluate its feasibility. The mean concentrations for HAAs from the pool waters were in the range of 6.8 and 48.6 μg/L which are far below the standard values set by United States Environmental Protection Agency.