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The subtle structural variations among carbohydrate isomers pose significant challenges for their identification and quantification. Here, we propose a strategy for rapid identification and quantification of isomeric disaccharides via derivatization with 4-(3-methyl-5-oxo-pyrazolin-1-yl) benzoic acid (CPMP) and analysing by ion mobility spectrometry (IMS). After derivatization, the ionization efficiency of disaccharides was significantly improved. The disaccharide isomers were distinguished by determining the different ion mobilities of CPMP-labelled disaccharides. Among them, [M + 2CPMP + H]+ was separated with a resolution of 1.484, almost achieving baseline separation. Subsequently, [M + CPMP + Na]+ was used for the relative quantification of lactose and maltose, showing a good linear relationship with R2 > 0.990. Finally, the method was successfully applied to the identification of lactose and maltose in beer and milk. The method is fast, accurate and effective for the identification of disaccharide isomers in complex samples. [ABSTRACT FROM AUTHOR]

In this work, zeolitic imidazolate framework (ZIF-8) coated mesoporous magnetic nanoparticles (Fe.sub.3O.sub.4@PDA@mSiO.sub.2@ZIF-8) were prepared through a facile and efficient strategy and used as a magnetic solid phase extraction platform for phthalates detection. Polydopamine (PDA) not only provides a hydrophilic layer, but also possesses [pi] electrons for aromatic compounds recognition; mSiO.sub.2 endows the nanoparticles with large surface area and regular channels, which facilitates the rapid transport of phthalates. The prepared Fe.sub.3O.sub.4@PDA@mSiO.sub.2@ZIF-8 with imposed properties showed ultrahigh efficiency and reusability for phthalates determination in human plasma samples. The linearity range was 50-8000 ng/mL, limits of detection were between 50-80 ng/mL, the intra-day RSDs were lower than 4.8%, inter-day RSDs were lower than 6.7%, the recoveries ranged from 90 to 107%. The new prepared nanoparticles displayed potential performance for aromatic compounds detection., Author(s): Baichun Wang [sup.1], Bin Liu [sup.1], Yinghua Yan [sup.1] Author Affiliations: (1) grid.203507.3, 0000 0000 8950 5267, School of Materials Science and Chemical Engineering, Institute of Mass Spectrometry, Ningbo [...]

In this work, a composite hydrogel material consisting of chitosan‐based composite hydrogel was prepared by a simple and rapid synthetic method and will be named three‐dimensional (3D)‐IL‐COF‐1@CS hydrogel. Possessing a stable 3D network structure and outstanding hydrophilicity, the novel hydrogel is capable of capturing glycopeptides. The 3D‐IL‐COF‐1@CS hydrogel showed good sensitivity (0.1 fmol/µL) and selectivity (1:2000). In addition, 19 glycopeptides were captured in standard samples. In the analysis of human serum, 148 glycopeptides assigned to 72 glycoproteins were assayed in the serum of normal individuals, and 245 glycopeptides corresponding to 100 glycoproteins were found in the serum of colorectal cancer (CRC) patients. More importantly, several functional programs based on Gene Ontology analysis supported molecular biological processes that may be relevant to the pathogenesis of CRC, including aging, fibrinogen complex, and arylesterase activity. The low cost, simplicity, rapid synthesis, and good enrichment performance have a great future in glycoproteomics analysis and related diseases. [ABSTRACT FROM AUTHOR]

In the present study, click chemistry and Schiff base reactions were simultaneously applied to prepare polymer brush (PEG)–functionalized MOF materials (UiO-66-NH2) and immobilized with Ti4+ (MOF-Brush-THBA-Ti4+) for phosphopeptide analysis. The material has a detection limit of 0.5 fmol, a selectivity of 2000:1, and a loading capacity of 133 mg/g for phosphopeptides. It also demonstrated great repeatability (10 cycles) and recovery rate (96.7 ± 1.4%). During the analysis of bio-samples, 4 specific phosphopeptides were identified in endogenous breast cancer serum, while 11 phosphopeptides were identified in skimmed milk. Moreover, 47 phosphopeptides correlated with 29 phosphorylated proteins were selectively identified from normal control serum, and 66 phosphopeptides correlated with 26 phosphorylated proteins were identified from breast cancer serum. Further analysis of gene ontology (GO) revealed that the detected phosphorylated proteins associated with breast cancer included positive regulation of receptor-mediated endocytosis, proteolysis, extracellular exosome, heparin binding, and chaperone binding. These findings suggest that these associated pathways might contribute to the etiology of breast cancer. Overall, this application exhibits enormous potential in the identification of phosphorylated peptides within bio-samples. [ABSTRACT FROM AUTHOR]