Confirmatory Analysis of Nitroimidazoles and Hydroxy Metabolites in Honey by Dispersive-Solid Phase Extraction and Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry

An ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry (UHPLC-MS/MS) method was developed and validated for confirmatory analysis of four nitroimidazoles and three hydroxy metabolites in honey. Honey samples were dissolved in 2% formic acid solution and nitroimidazoles and metabolites were isolated and enriched by dispersive-solid phase extraction using mixed-mode strong cation-exchange sorbent. The determination involves separation of analytes on an UHPLC C18 column and detection by multiple reaction monitoring in positive ionization mode. The recovery of the method was ranged from 90.2 to 105.6% with inter-day relative standard deviations of less than 11.2%. The limits of detection and limits of quantification were in the ranges of 0.02⁻0.07 µg/kg and 0.05⁻0.2 µg/kg, respectively. Honey samples from the market were analyzed to demonstrate the applicability of the proposed method

Converting amorphous kraft lignin to hollow carbon shell frameworks as electrode materials for lithium-ion batteries and supercapacitors

Lignin has been widely used as a high-quality carbon source in the preparation of carbon electrodes. Because the skeleton of lignin molecules is an unordered three-dimensional network structure, it is difficult to obtain highperformance porous carbon electrode materials with regular structures by conventional carbonization methods. To improve the electrochemical performance of lignin-based carbon, green, convenient and massproduced lignin-based porous hollow carbon shell frameworks (HCSFs) were proposed. With the help of electrostatic forces, lignin/silica nanocomposites were generated by an insitu self-assembly and coprecipitation method using quaternary ammonium lignin and sodium silicate as raw materials. After carbonization and activation, HCSFs with hollow porous frame structures rich in nitrogen were obtained. The prepared HCSFs can maintain a reversible specific capacity of 480 mA h g(-1) after 200 cycles at 200 mA g(-1) as a lithium-ion battery anode, and they can also maintain a specific capacity of 180.4 mF g(-1) after 10,000 cycles at 1 A g-1 as a supercapacitor electrode. Their better energy storage performance is mainly attributed to the special hollow shell structure of HCSFs, which can provide channels for rapid ion transport, and the doping of nitrogen atoms can also provide an increase in the number of storage sites. This work provides a theoretical basis for the preparation of carbon shells from biomass and widens the application field for the high value utilization of industrial lignin

Determination of Tranquilizers in Swine Urine by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

A rapid, reliable, and sensitive method was developed for the determination of ten tranquilizers in swine urine. Sample preparation was based on solid-phase extraction, which combined isolation of the compounds and sample cleanup in a single step. Separation was performed on a reversed phase C18 column by gradient elution with a chromatographic run time of seven minutes, consisting of 0.1% formic acid in water and acetonitrile as the mobile phase. Multiple reaction monitoring in positive mode was applied for data acquisition. Matrix-matched calibration was used for quantification and good linearity was obtained with coefficients of determination higher than 0.99. The average recoveries of fortified samples at concentrations between 0.05 and 10 µg/L ranged from 85% to 106% with interday relative standard deviations of less than 13% in all cases. The limits of detection and limits of quantification obtained for tranquilizers in the urine were in the ranges of 0.03⁻0.1 µg/L and 0.05⁻0.25 µg/L, respectively. The applicability of the proposed method was demonstrated by analyzing real samples; diazepam was detected at concentrations between 0.3 and 0.6 μg/L

Lignin-based materials for electrochemical energy storage devices

Lignin is the most abundant aromatic polymer in nature, which is rich in a large number of benzene ring structures and active functional groups. The molecular structure of lignin has unique designability and controllability, and is a class of functional materials with great application prospects in energy storage and conversion. Here, this review firstly focuses on the concept, classification, and physicochemical property of lignin. Then, the application research of lignin in the field of electrochemical storage materials and devices are summarized, such as lignin-carbon materials and lignin-carbon composites in supercapacitors and secondary batteries. Finally, this review points out the bottlenecks that need to be solved urgently and the prospects for future research priorities

Preparation and Performance of Lignin-Based Multifunctional Superhydrophobic Coating

Superhydrophobic coatings have drawn much attention in recent years for their widespread potential applications. However, there are challenges to find a simple and cost-effective approach to prepare superhydrophobic materials and coatings using natural polymer. Herein, we prepared a kraft lignin-based superhydrophobic powder via modifying kraft lignin through 1H, 1H, 2H, 2H-perfluorodecyl-triethoxysilane (PFDTES) substitution reaction, and constructed superhydrophobic coatings by direct spraying the suspended PFDTES-Lignin powder on different substrates, including glass, wood, metal and paper. The prepared lignin-based coatings have excellent repellency to water, with a water contact angle of 164.7°, as well as good friction resistance, acid resistance, alkali resistance, salt resistance properties and quite good self-cleaning performance. After 30 cycles of sand friction or being stayed in 2 mol/L HCl, 0.25 mol/L NaOH and 2 mol/L NaCl solution for 30 min, the coatings still retain super hydrophobic capability, with contact angles higher than 150°. The superhydrophobic performance of PFDTES-Lignin coatings is mainly attributed to the constructed high surface roughness and the low surface energy afforded by modified lignin. This lignin-based polymer coating is low-cost, scalable, and has huge potential application in different fields, providing a simple way for the value-added utilization of kraft lignin

Scalable production of 3D plum-pudding-like Si/C spheres: Towards practical application in Li-ion batteries

Nanosized silicon (Si) has been widely investigated as a promising material for next generation lithium ion battery (LIB) anodes because of its ultrahigh capacity. However, only a few results can satisfy all aspects towards practical application, particularly the problems like low initial Coulombic efficiency, low volumetric capacity, huge volume change (> 290%), complicated fabrication methods, and especially low production remain unsolved. Here, we propose a 3D plum-pudding-like Si/C micro-/nano- composite (SiNS/C) design for an anode via quasi-industrial-scale production that tackles all these problems: largescale production of similar to 300 g/h, ultra-high initial Coulombic efficiency (ICE) of 88%, high volumetric capacity of similar to 1244 mA h cm(-3), and improved rate capability have been achieved. An in-situ high-resolution transmission electron microscopy (HRTEM) probing has testified that a design of Si/C nanospheres with the appropriate size enables only small volume variations (upon lithiation), e.g. similar to 48% for 50 nm Si/C spheres in the SiNS/C particles as required for the practical applications, and leads to the formation of a stable thin SEI layer on the outer surface of carbon coating layer. (C) 2016 Elsevier Ltd. All rights reserved