In-syringe dispersive solid-phase extraction using dissolvable layered double oxide hollow spheres as sorbent followed by high-performance liquid chromatography for determination of 11 phenols in river water.

Layered double oxide hollow spheres (LDO-HSs) were synthesized and employed as a dissolvable sorbent in dispersive solid-phase extraction (DSPE) to extract eleven United States Environmental Protection Agency's priority phenols from aqueous samples. With their higher specific surface area, LDO-HSs showed much higher extraction efficiency than normal layered double hydroxides and layered double oxides. The entire extraction process was accomplished in a syringe. After DSPE, the sorbent with the analytes was isolated conveniently by directly expelling the spent sample solution out of the syringe. The analyte-enriched sorbent was then subsequently dissolved by withdrawing an acidic solution into the syringe. The final extract was analyzed by high-performance liquid chromatography with ultraviolet detection. The results showed that this method provided low limits of detection for the phenols (0.005-0.153 μg/L), good linearity (r(2)≥ 0.9956) and relative standard deviations of ≤ 6.7%. The optimized method was applied to water samples from 3 rivers. This simple extraction procedure was demonstrated to be a fast, efficient and convenient DSPE approach.