Non-covalently lactose imprinted polymers and recognition of saccharides in aqueous solutions

Development of a Non-Covalent Molecularly Imprinted Polymer via Precipitation Method for the Selective Separation of D-Xylose From Sugarcane Residues

The agro-industry generates substantial waste, necessitating eco-friendly solutions. This study introduces a novel molecularly imprinted polymer (MIPs) for the selective separation of D-xylose from sugarcane residues. A non-covalent imprinted polymer was synthesized via precipitation and optimized through D-xylose adsorption assays. The polymer demonstrated an Imprinting Factor of 3.34, adsorption equilibrium within 30 min, notable reusability retaining over 95% of its adsorption capacity after three cycles, and high selectivity coefficients (α > 2.00) for all saccharides tested. The adsorption isotherm followed the Langmuir model. Characterization confirmed successful imprinting, with the imprinted polymer exhibiting a surface area of 69.4 m2/g and pore volume of 0.26 cm3/g, compared to 8.7 m2/g and 0.03 cm3/g for the non-imprinted polymer. D-xylose separation was tested using hemicellulosic hydrolysate from sugarcane straw and bagasse. The polymer applied as a sorbent in dispersive solid-phase extraction with the hydrolysate achieved 90.29 ± 1.27% D-xylose adsorption. Desorption in pure water recovered 81.48 ± 1.22% of the adsorbed D-xylose. This method advances separation techniques, offering an efficient solution for sample pre-treatment and expanding the application of MIPs.

Liquid Chromatography Analysis of Clozapine in Rat Brain Tissue, Using its Molecularly Imprinted Polymer after Administration of Toxic Dose of Drug and Lipid Emulsion Therapy

Background:

Molecularly imprinted polymers (MIPs) are synthetic polymers that have a selective site for a given analyte, or a group of structurally related compounds, that make them ideal polymers to be used in separation processes.

Objective:

An optimized molecularly imprinted polymer was selected and applied for selective extraction and analysis of clozapine in rat brain tissue.

Methods:

A molecularly imprinted solid-phase extraction (MISPE) method was developed for preconcentration and cleanup of clozapine in rat brain samples before HPLC-UV analysis. The extraction and analytical process was calibrated in the range of 0.025-100 ppm. Clozapine recovery in this MISPE process was calculated between 99.40 and 102.96%. The limit of detection (LOD) and the limit of quantification (LOQ) of the assay were 0.003 and 0.025 ppm, respectively. Intra-day precision values for clozapine concentrations of 0.125 and 0.025 ppm were 5.30 and 3.55%, whereas inter-day precision values of these concentrations were 9.23 and 6.15%, respectively. In this study, the effect of lipid emulsion infusion in reducing the brain concentration of drug was also evaluated.

Results:

The data indicated that calibrated method was successfully applied for the analysis of clozapine in the real rat brain samples after administration of a toxic dose to animal. Finally, the efficacy of lipid emulsion therapy in reducing the brain tissue concentration of clozapine after toxic administration of drug was determined.

Conclusion:

The proposed MISPE method could be applied in the extraction and preconcentration before HPLC-UV analysis of clozapine in rat brain tissue.

Development of solid-phase microextraction coupled with liquid chromatography for analysis of tramadol in brain tissue using its molecularly imprinted polymer

In this work, performance of a molecularly imprinted polymer (MIP) as a selective solid-phase microextraction sorbent for the extraction and enrichment of tramadol in aqueous solution and rabbit brain tissue, is described. Binding properties of MIPs were studied in comparison with their nonimprinted polymer (NIP). Ten milligrams of the optimized MIP was then evaluated as a sorbent, for preconcentration, in molecularly imprinted solid-phase microextraction (MISPME) of tramadol from aqueous solution and rabbit brain tissue. The analytical method was calibrated in the range of 0.004 ppm (4 ng mL^-1 ) and 10 ppm (10 μg mL^-1 ) in aqueous media and in the ranges of 0.01 and 10 ppm in rabbit brain tissue, respectively. The results indicated significantly higher binding affinity of MIPs to tramadol, in comparison with NIP. The MISPME procedure was developed and optimized with a recovery of 81.12-107.54% in aqueous solution and 76.16-91.20% in rabbit brain tissue. The inter- and intra-day variation values were <8.24 and 5.06%, respectively. Finally the calibrated method was applied for determination of tramadol in real rabbit brain tissue samples after administration of a lethal dose. Our data demonstrated the potential of MISPME for rapid, sensitive and cost-effective sample analysis.