Polyvinylpyrrolidone/Single-Walled Carbon Nanotubes Incorporated Polyhipe Monoliths Followed by HPLC for Determination of Tetracycline Antibiotics in Water Samples

Abstract In this work, a porous polyvinylpyrrolidone/single-walled carbon nanotube incorporated polymerized high internal phase emulsion (PVP/SWCNT-polyHIPE) monolithic column was fabricated and developed as a solid phase extraction (SPE) adsorbent coupled with high performance liquid chromatography-fluorescence detection (SPE-HPLC-FLD) for the determination of tetracycline (TC), oxytetracycline (OTC), chlorotetracycline (CTC), and doxycycline (DC) in environmental water samples. The proposed monolithic sorbent was easily produced by in-situ polymerizing of high internal phase emulsions (HIPEs), and performed high extraction ability to the four tetracycline antibiotics (TCs). The extraction conditions including sample pH, sample flow rate, sample volume, desorption solvent and its volume were studied by investigating the recoveries of the four TCs, and the optimal extraction conditions were obtained. Under the optimized conditions, the PVP/SWCNT-polyHIPE based SPE-HPLC-FLD method exhibited good linearity in the range of 20–800 ng/mL for four tetracycline antibiotics with correlation coefficients higher than 0.9996. For water samples, the detection limits (LODs, S/N = 3) ranged from 1.0–2.5 ng mL −1 for four tetracycline antibiotics. The intra-day ( n = 15) and inter-day ( n = 5) precisions (expressed in terms of relative standard deviation (RSD %) were in the range of 0.5–2.2 and 1.3–5.7%, respectively. The spiked recoveries were in the range of 85.0–101.7 % with RSDs lower than 4.0%. Furthermore, the prepared polyHIPE monoliths allowed more than 100 extraction cycles without any loss in the extraction efficiency. The developed method enables us to detect trace tetracycline antibiotics in water samples. The method can be useful in the extraction and determination of antibiotics in all kinds of environmental water samples.