Rapid HPLC-DAD quantitation of sulfonamides in honey using poly(methacrylic acid-ethylene dimethacrylate) monolith modified with 3-(trimethoxysilyl)propyl methacrylate-grafted sodium titanate nanotubes

Abstract

3-(Trimethoxysilyl)propyl methacrylate-grafted sodium titanate nanotubes were synthesized and used as monomers to functionalize a poly(methacrylic acid-ethylene dimethacrylate) monolithic column. Various techniques, including scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and thermal gravimetric analysis were employed to characterize the synthesized monolith. The modified polymer monolithic column was further applied to the determination of sulfonamides in honey samples coupled with high performance liquid chromatography-diode array detection. Several experimental parameters affecting the extraction efficiency were investigated by single-factor experiments, such as the sample pH, sample flow rate, sample volume, eluent flow rate, and eluent type. The first four factors were then further evaluated by means of the Taguchi's L₉(3⁴) orthogonal array experimental design. Under the optimized conditions, good linearities were obtained for all targets with squared regression coefficient values greater than 0.9937. The limits of detection (S/N = 3) and limits of quantitation (S/N = 10) were in the range of 0.68–1.42 and 2.28–4.72 μg kg⁻¹, respectively. The intra-day and inter-day relative standard deviations were determined to be from 1.9% to 6.9%. The recoveries of targets at different spiked levels ranged from 80.3% to 109.9% with relative standard deviations less than 9.5%, suggesting a promising prospect of the developed method in the application of real samples.