Determination of tetracycline residues in lake water by on-line coupling of molecularly imprinted solid-phase extraction with high performance liquid chromatography

Abstract

A new method has been developed for the determination of tetracycline residues in water samples by on-line solid-phase extraction-HPLC analysis method. Tetracycline-imprinted microspheres, synthesized by reversible addition–fragmentation chain transfer precipitation polymerization, were applied for the extraction of the tetracyclines. Tetracycline residues were selectively extracted from 10.0 mL lake water using the molecularly imprinted solid-phase extraction (MISPE) method. After the sample clean-up, tetracyclines were back-flushed into a reversed-phase C₁₈ analytical column and oxytetracycline, tetracycline and doxycycline were separated for quantification. The recoveries of three tetracyclines in the spiked lake water were between 83.2% and 111.0% with relative standard deviations (RSDs) <5.3%, demonstrating that the established MISPE-HPLC method has good accuracy and precision. Linearity in the range of 1–200 μg L⁻¹ was obtained. The detection limits and quantification limits for the analytes were 0.08–1.02 μg L⁻¹ and 0.41–3.56 μg L⁻¹, respectively. The enhancement factors, which ranged from 376 to 528, indicated that the MISPE has the ability to enrich trace tetracycline residues. The results demonstrated that this method can be used in the determination of tetracyclines in environmental water samples with good sensitivity and efficiency.