Development of air-assisted dispersive micro-solid-phase extraction-based supramolecular solvent-mediated Fe3O4@Cu-Fe-LDH for the determination of tramadol in biological samples

A simple method, air-assisted dispersive micro-solid-phase extraction-based supramolecular solvent was developed for the preconcentration of tramadol in biological samples prior to gas chromatography-flame ionization detection. A new type of carrier liquid, supramolecular solvent based on a mixture of 1-dodecanol and tetrahydrofuran was combined with layered double hydroxide coated on a magnetic nanoparticle (Fe3O4@SiO2@Cu-Fe-LDH). The supramolecular solvent was injected into the solution containing Fe3O4@SiO2@Cu-Fe-LDH in order to provide high stability and dispersion of the sorbent without any stabilizer agent. Air assisted was applied to enhance the dispersion of the sorbent and solvent. A number of analytical techniques such as Fourier transform-infrared spectrometry, field emission scanning electron microscope, energy-dispersive X-ray spectroscopy and X-ray diffraction measurements were applied to assess the surface chemical characteristics of Fe3O4@SiO2@Cu-Fe-LDH nanoparticles. The effects of important parameters on the extraction recovery were also investigated. Under optimized conditions, the limits of detection and quantification were obtained in the range of 0.9-2.4 and 2.7-7.5 mu g L-1 with preconcentration factors in the range of 450-472 in biological samples. This method was used for the determination of tramadol in biological samples (plasma, urine and saliva samples) with good recoveries.