Extraction of trace polychlorinated biphenyls in environmental waters by well-dispersed velvet-like magnetic carbon nitride nanocomposites.

A velvet-like magnetic carbon nitride nanocomposites synthesized by chemical co-precipitation was used to develop a highly efficient magnetic solid-phase extraction method for the pre-concentration of trace polychlorinated biphenyls (PCBs) in water samples. The advantages of this nanocomposite such as large surface area, good dispersity, low solvent consumption, rapid analyte adsorption (30s) and reusability make it a good sorbent. Factors affecting extraction efficiency were systematically investigated and optimized by response surface methodology (RSM). Under optimal experimental conditions, the limits of detection (LODs S/N=3) of the developed method for PCBs investigated were in the range of 9.0×10