Vesicular supramolecular solvent-based microextraction followed by high performance liquid chromatographic analysis of tetracyclines.

A simple liquid phase microextraction (LPME) using a vesicular supramolecular solvent (SUPRAS) as the green extraction solvent has been developed for the enrichment of tetracycline antibiotics (TCs) prior to their analysis by reversed phase high performance liquid chromatography. SUPRAS was prepared from a mixture of cationic surfactants: didodecyldimethylammonium bromide (DDAB) and dodecyltrimethylammonium bromide (DTAB) under salt (NaCl) addition for coacervation. The LPME is based on electrostatic interaction between TCs and SUPRAS under salt induced phase separation. Under the optimum conditions, high enrichment factors (EFs) of 48-198, low limits of detection (LODs) in the range of 0.7-3.4 μg L-1 and good precisions with relative standard deviations (RSDs) less than 7.85% were obtained. The applicability of the proposed method was demonstrated for the determination of TCs in milk, egg and honey samples. In addition, morphology, particle sizes and zeta potential of SUPRAS were also investigated.