Electrospinning of magnetic cellulose tris-(4-methylbenzoate) microparticles for enantioselective adsorption of racemic drug.

In this work, we introduce electrospinning to prepare magnetic enantioselective material for the first time. Multianalytical tools were used to characterize the resulted magnetic cellulose tris-(4-methylbenzoate) particles including transmission electron microscopy, SEM, FTIR spectroscopy, thermogravimetric analysis, X-ray diffractometer. Under the optimum conditions, the resulted particles were well-shaped sphere with a diameter range of 800 nm to 2 µm and high magnetic sensitivity. The enantioselectivity of the adsorbents was evaluated using racemic ibuprofen as a model drug; an e.e. value of -4.78% (where e.e. is enantiomeric excess) was achieved in a single adsorption stage. We hope that our finding provides an efficient and economical procedure for the preparation of magnetic enantioselective materials with high selectivity and reproducibility.

Facile synthesis of carboxymethyl-ß-cyclodextrin conjugated magnetic nanoparticles for selective enrichment of glycopeptides.

RATIONALE: Selective enrichment of glycopeptides prior to mass spectrometry (MS) analysis is essential due to the low abundance of the modified glycopeptides in complex samples, ion suppression effects during MS ionization and detection caused by the co-presence of non-glycosylated peptides, etc. Among different enrichment approaches, hydrophilic interaction liquid chromatography (HILIC)-based magnetic separation has become one of the most popular methods in recent years, due to its high efficiency and selectivity for glycopeptide enrichment. METHODS: Herein, novel carboxymethyl-ß-cyclodextrin (CMCD)-modified magnetic nanoparticles (MNPs) were synthesized via a carbodiimide activation method. CMCD was covalently bonded with the -OH group on the surface of MNPs through carbodiimide, and the proposed procedure provides a rapid and efficient alternative for glycopeptide enrichment due to its stable interaction, time-saving, and easy operation. RESULTS: The prepared absorbents with a mean diameter of 15 nm demonstrated a strong magnetic response to an externally applied magnetic field. The results of thermogravimetric analysis showed the content of bound CMCD was 3 wt%. The outer CMCD layer conjugated on the Fe3 O4 core showed high hydrophilic surface property. In the analysis of a complex mouse liver sample, a total of 666 unique N-glycosylation sites corresponding to 494 glycosylated proteins were identified successfully. CONCLUSIONS: The study demonstrated an easy-to-use CMCD-modified MNPs-based approach with high selectivity and high capacity in the enrichment of low-abundance glycopeptides from complex biological samples. Copyright © 2016 John Wiley & Sons, Ltd.

Zirconium(IV) functionalized magnetic nanocomposites for extraction of organophosphorus pesticides from environmental water samples.

The widespread use of organophosphate pesticides (OPPs) in agriculture leads to residue accumulation in the environment which is dangerous to human health and disrupts the ecological balance. In this work, one nanocomposite immobilized zirconium (Zr, IV) was prepared and used as the affinity probes to quickly and selectively extract organophosphorus pesticides (OPPs) from water samples. The Fe3O4-ethylenediamine tetraacetic acid (EDTA)@Zr(IV) nanocomposites (NPs) were prepared by simply mixing Zr(IV) ions with Fe3O4-EDTA NPs synthesized by one-pot chemical co-precipitation method. The immobilized Zr(IV) ions were further utilized to capture OPPs based on their high affinity for the phosphate moiety in OPPs. Coupled with GC-MS, four OPPs were used as models to demonstrate the feasibility of this approach. Under the optimum conditions, the limits of detection for target OPPs were in the range of 0.10-10.30ngmL(-1) with relative standard deviations (RSDs) of 0.61-4.40% (n=3), respectively. The linear ranges were over three orders of magnitudes (correlation coefficients, R(2)>0.9995). The Fe3O4-EDTA@Zr(IV) NPs were successfully applied to extract OPPs samples with recoveries of 86.95-112.60% and RSDs of 1.20-10.42% (n=3) from two spiked real water. By the proposed method, the matrix interference could be effectively eliminated. We hope our finding can provide a promising alternative for the fast extraction of OPPs from complex real samples.