Ultra-preconcentration of common herbicides in aqueous samples using solid phase extraction combined with dispersive liquid–liquid microextraction followed by HPLC–UV

An analytical method, solid-phase extraction combined with dispersive liquid–liquid microextraction (SPE–DLLME), was established to extract and determine the herbicides in aqueous samples. In this method, herbicides were adsorbed from a large volume of aqueous samples (100 mL) into 500 mg functionalized octadecyl silica (C18) sorbent. After the elution of the desired compounds from the sorbent by using acetone, DLLME technique was performed on...