Spectrofluorometric determination of venlafaxine in biological samples after selective extraction on the superparamagnetic surface molecularly imprinted nanoparticles

This paper reports on a procedure for selective extraction of the venlafaxine (VEN) drug from biological samples before its sensitive spectrofluorometric determination. In this regard, a layer of VEN-imprinted polymer was coated onto the surface of magnetite nanoparticles. The synthesized nanoparticles were characterized using FT-IR, VSM, XRD and TEM measurements. Various factors that could potentially affect the extraction efficiency of VEN (i.e. solution pH, nanoparticle dosage and contact time) have been optimized using a one-at-a-time method. The prepared magnetic adsorbent could disperse well in water medium and could be easily separated magnetically from the medium after loading with the adsorbate. The loaded VEN could be easily desorbed with a mixture of methanol and HCl and determined spectrofluorometrically at 598 nm. The results showed that using the proposed method VEN can be determined spectrofluorometrically in the linear concentration range of 2.0-400.0 ng mL(-1) with a limit of detection as low as 1.2 ng mL(-1). The results of human urine and blood serum analysis showed that the method is a good candidate for biological sample analysis purposes.