Rapid determination of trace phenols migrating into drinking water from plastic-based pipe materials and household water treatment equipment using vortex-assisted emulsification microextraction

摘要

A simple and rapid vortex-assisted emulsification microextraction (VAEME) method combined with spectrophotometry was developed for the determination of trace phenols migrating into potable water from plastic-based pipe materials and household water treatment equipments. The oxidative coupling reaction of phenolic compounds with 4-aminoantipyrine was carried out employing potassium peroxodisulfate as the oxidant in alkaline medium. A cloudy mixture was formed facilitating mass transfer of the reaction products into the fine droplets of toluene. The extraction equilibrium was rapidly achieved within 3 min by a combination of vibration and heating. The extract was concentrated in the narrow neck of the vessel, and could be easily withdrawn with a syringe. The VAEME method effectively avoids the analytical errors resulting from fluid leakage, which often occurs during conventional liquida€“liquid extraction with a separating funnel. Under the optimal conditions, linearity ranges of 0.2a€“180 ??g La?’1 and detection limits of 0.08 ??g La?’1 (expressed as C6H5OH concentration) were achieved. This approach was successfully applied in the determination of trace amounts of phenols in 36 solutions used to soak a variety of matrices. The recoveries were in the range of 86.0a€“99.8% and the relative standard deviations ranged from 0.53% to 6.5%. Compared with the official method, the proposed method was faster, more sensitive and required lower amounts of reagents.