Li-N Interaction Induced Deep Eutectic Gel Polymer Electrolyte for High Performance Lithium-Metal Batteries.

As emerging eutectic mixtures, deep eutectic electrolytes (DEEs) show unique properties for Li-metal batteries (LMBs). However, the limited choice and inferior electrode compatibility hinder their further development in LMBs. Herein, we report a new 1,2-dimethylimidazole (DMIm)-based deep eutectic gel polymer electrolyte induced by Li-N interaction. We demonstrate that incorporating electron-withdrawing polyvinylidene difluoride (PVDF) polymer into the DMIm-based DEE changes the coordination environment of Li+ ions, leading to a high transference number of Li+ ions (0.65) and superior interface stability between the electrolyte and Li anode. The deep eutectic gel polymer electrolyte exhibits excellent non-flammability, high ionic conductivity (1.67 mS cm-1 at 30 °C), and high oxidation voltage (up to 4.35 V vs. Li/Li+ ). The Li||LFP cell based on the newly developed deep eutectic gel polymer electrolyte can achieve superior long-term cycling stability at a wide range of rates.

1,2-Dimethylimidazole-4-sulfonyl chloride (DMISC), a novel derivatization strategy for the analysis of propofol by LC-ESI-MS/MS.

Analysis of the anesthetic agent propofol in biological samples by LC-MS/MS is a great challenge due to weak fragmentation and poor ionization efficacy of propofol resulting in weak signal intensities. Improvements of the ionization and fragmentation efficacy can be achieved by conversion of propofol to its dimethylimidazolesulfonyl (DMIS) derivative by a derivatization reaction using 1,2-dimethylimidazole-4-sulfonyl chloride (DMISC). This DMIS derivative produced intense [M + H]+ ions in positive-ion LC-ESI-MS/MS with the dimethylimidazole moieties representing the most abundant product ions. Derivatization of serum samples is achieved by direct conversion of the acetonitrile supernatant of a protein precipitation with DMISC followed by a double liquid-liquid extraction using n-hexane. Reliability of the method was confirmed under consideration of the validation parameters selectivity, linearity, accuracy and precision, analytical limits, and processed sample stability. Linearity was demonstrated over the whole calibration range from 5 to 1000 ng/ml with the use of a 1/x 2 weighting. Stability of the processed samples was verified for a time period of up to 25 h. Due to its high sensitivity, appropriate quantification and detection limits (LLoQ = 5 ng/ml, LoD = 0.95 ng/ml) for toxicological propofol analyses could be achieved. Applicability of the method to biological samples could be verified by analysis of a human serum sample collected after propofol-induced sedation. Graphical abstract A novel derivatization strategy using 1,2-dimethylimidazole-4-sulfonyl chloride (DMISC) was developed to improve the ionization and fragmentation efficacy of propofol for LC-ESI-MS/MS analysis.

Rapid and quantitative detection of 4(5)-methylimidazole in caramel colours: A novel fluorescent-based immunochromatographic assay.

A novel fluorescence-based immunochromatographic assay (ICA) for rapid detecting 4(5)-methylimidazole (4-MI) is presented in this study. In our work, the conjugates of fluorescent microspheres (FMs) and 4-MI monoclonal antibody were used as probe for ICA. Under optimal conditions, a standard curve of ICA-based detection of 4-MI was developed, linear detection ranged from 0.50 to 32.0 mg/L. The cross-reactivities were observed less than 3.93% by detecting 6 selected structural analogues of 4-MI. The recoveries of 4-MI in caramels detection were ranged from 82.85% to 102.31%, with the coefficient of variation (n = 3) below 9.06%. Quantitative comparison of the established fluorescence-based ICA with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) analysis of real caramel colour samples indicated a good correlation among the methods. Therefore, our developed fluorescence-based ICA method shows great potential for simple, rapid, sensitive, and cost-effective quantitative detection of 4-MI in food safety control.

Synthesis, and spectroscopic studies of charge transfer complex of 1,2-dimethylimidazole as an electron donor with π-acceptor 2,4-dinitro-1-naphthol in different polar solvents.

The charge transfer (CT) complex of 1,2-dimethylimidazole (DMI) as an electron donor with π acceptor 2,4-dinitro-1-naphthol (DNN) has been studied spectrophotometrically in different solvents like chloroform, acetonitrile, methanol, methylene chloride, etc. at room temperature. The CT complex which is formed through the transfer of lone pair electrons from DMI to DNN exhibits well resolved CT bands and the regions of these bands were remarkably different from those of the donor and acceptor. The stoichiometry of the CT complex was found to be 1:1 by a straight-line method between donor and acceptor with maximum absorption bands. The novel CT complex has been characterized by FTIR, TGA-DTA, powder XRD, (1)H NMR and (13)C NMR spectroscopic techniques. The Benesi-Hildebrand equation has been used to determine the formation constant (K(CT)), molar extinction coefficient (ε(CT)), standard gibbs free energy (ΔG°) and other physical parameters of the CT complex. The formation constant recorded higher values and molar extinction coefficient recorded lower values in chloroform compared with methylene chloride, methanol and acetonitrile, confirming the strong interaction between the molecular orbital's of donor and acceptor in the ground state in less polar solvent. This CT complex has been studied by absorption spectra of donor 1,2-dimethylimidazole (DMI) and acceptor 2,4-dinitro-1-naphthol (DNN) by using the spectrophotometric technique in various solvents at room temperature.

Development of a monoclonal antibody-based indirect competitive immunosorbent assay for 4(5)-Methylimidazole detection in caramels.

In this study, an indirect competitive enzyme-linked immunoassay (ic-ELISA) based on monoclonal antibody for 4(5)-Methylimidazole (4-MI) detection was described. The artificial antigens were prepared by conjugating bovine serum albumin (BSA) or ovalbumin (OVA) with the hapten of 4-MI. And monoclonal antibody, evaluated by ic-ELISA, was obtained by immunizing BABL/c mice. After optimizing, a standard curve for ic-ELISA detection on 4-MI was obtained with the linear detection range of 0.64-20.48 mg/L. The cross-reactivity (CR) of all the structural analogues of 4-MI was less than 5.62%. The recoveries of 4-MI in caramels detection were ranged from 88.69% to 114.09%, with relative standard deviation (n=3) below 8.07%. The results suggested that the established ic-ELISA is promising for 4-MI commercial detection in caramels.

Critical practical aspects in the application of liquid chromatography-mass spectrometric studies for the characterization of impurities and degradation products.

Liquid chromatography-mass spectrometry (LC-MS) is considered today as a mainstay tool for the structure characterization of minor components like impurities (IMPs) and degradation products (DPs) in drug substances and products. A multi-step systematic strategy for the purpose involves high resolution mass and multi-stage mass studies on both the drug and IMPs/DPs, followed by comparison of their fragmentation profiles. Its successful application requires consideration of many practical aspects at each step. The same are critically discussed in this review.