A novel molecular imprinting polymer for the selective adsorption of D-arabinitol from spiked urine

In this research, molecular imprinting polymers (MIPs) for D-arabinitol were synthesized using a bulk polymerization method through a noncovalent approach. The MIPs were prepared by using D-arabinitol as a template, acrylamide as a functional monomer, ethylene glycol dimethacrylateas cross-linker, benzoyl peroxide as an initiator and dimethyl sulfoxideas a porogen. MIPS was synthesized in several formulas with a different molar ratio of template to functional monomers and cross-linker. Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were used to characterize the MIPs produced. A batch rebinding assay was used to test the binding efficiency of each formula. Batch rebinding test results revealed that MIPsF3 with a molar ratio of the template: monomer and crosslinker ratio respectively (1: 4: 25) had the highest binding capacity at 1.56 mgg ^-1 . The results of isotherm adsorption showed that the MIPs produced followed the Freundlich equation with an R-value of 0.97. The MIPs produced was also selective toward its isomeric compounds (i.e. L-arabinitol, adonitol, xylitol, and glucose). The extraction efficiency of the MIPs against D-arabinitol was 88.98%.     

The chromatomembrane method used for sample preparations in the spectrophotometric determination of zinc and copper in pharmaceuticals

The chromatomembrane cell (CMC) was used to extract zinc and copper and to preconcentrate them for their separation from pharmaceutical preparations. The method performance was evaluated at the determination of the enrichment factor, the linearity of response, the reproducibility, the accuracy and the sensitivity. In practice a five-fold enrichment has been enough provided that sample sizes of 0.825 ml were introduced. Good linearities for zinc and copper (r² > 0.99) were observed under this condition. The relative standard deviation (<3%) proved the good reproducibility of the method. The accuracy has been verified using model solutions, which were prepared from a certified reference. Recoveries of 98.8, 99.5 and 100.3% were achieved with solutions containing 0.1, 0.3 and 0.5 μg ml⁻¹ Zn(II), respectively. In case of copper 101.2, 99.6 and 100.6% recovery were obtained for 0.1, 0.4 and 0.7 μg ml⁻¹ Cu(II), respectively. The detection limits (three-fold of the signal-to-noise ratio) were estimated at 0.04 μg ml⁻¹ for both. The proposed method was applied on pharmaceutical preparations and the results were found to be in a good agreement with the contents guaranteed by the producers.