A rapid method based on solid phase extraction-ultra performance convergence chromatography was established for the determination of bisphenol A (BPA) in environmental water. The chromatographic conditions and solid phase extraction conditions were investigated, and the rapid and effective analysis of BPA could be achieved in 4 min. The results showed that the method has a good linearity with BPA in the range of 0.20-100 mg/L with correlation coefficient (R2) of 0.9996. Furthermore, the limit of detection (LOD) was 0.01 mg/L. The spiked recovery (R) and relative standard deviation (RSD) were 89.7%∼109.2% and 2.78%∼4.66%, respectively. The method is rapid, simple, accurate and reliable, which can provide technical reference for the detection of BPA in environmental water.
Graphene oxide (GO)/polyaniline (PANI) composite are synthesized via in situ polymerization in the presence of grapheme oxide under acid conditions. The GO/PANI was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) and electrochemical testing. The cathodes prepared using PANI and GO/PANI delivered initial discharge capacities of 78mAh/g and 104.4mAh/g ,respectively stable reversible capacities of 58.5mAh/g and 103.7mAh/g after 50 chargedischarge cycles. The GO enhances the discharge capacity of the PANI electrode material. GO/PANI is a good candidate as electrode material in lithium ion batteries
The migration rules of two triazine type of UV absorbents (UV-1577 and UV-1579) from polypropylene (PP) food contact materials to food simulant were investigated. A rapid detection method of UV-1577 and UV-1579 in PP food contact materials was established by ultra-performance convergence chromatography (UPC 2 ). The optimal extraction method of the initial solution was determined, and the pretreatment methods of two UV absorbents in the liquid simulants were optimized. Experiment results showed that the interaction effects between the two UV absorbers and the liquid simulants were weak, and the migration behavior was the most obvious in the fatty simulant of isooctane. At the same temperature, the migration amount of both UV-1577 and UV-1579 increased with the extension of time, and UV-1577 was more prone to migration than UV-1579. Within a certain range, the migration amount of the two UV absorbents increased significantly with the increase of the migration temperature. The higher the temperature was, the shorter the time required to reach the equilibrium.
The ultra performance convergence chromatography method was developed to detect the migration of four phthalates (PAEs) in plastic food contact materials. Plastic food contact materials samples are immersed with oil-based (isooctane) and water-based simulants (10% ethanol, 4% acetic acid and water), respectively. The pre-treatment method of four kinds of PAEs in the simulated immersion solution was optimized. The relationship between migration behaviour and the simulants, migration temperature and migration time were studied. The results show that PAEs were more likely to migrate in oily simulants. Within a certain range, the migration amount increased with the extension of immersion time. The migration rate and amount enhanced with the temperature.
Olivine-type LiFePO4/C composite cathode materials were synthesized by a solid-state reaction method in an inert atmosphere. Glycerin, glucose and citric acid were added as different conductive precursors before the formation of the crystalline phase. The effects of the carbon source on the properties of as-synthesized cathode materials were investigated. SEM and LSD measurement indicate that the particle size of the samples produced by glycerin and glucose distributed in a narrow way, while the particle of the sample produced by citric acid varied from submicron to several micron. The galvanostatically charge and discharge tests show that the material obtained by glucose gives a maximal specific discharge capacity of 142.5 mAh•g-1 in the first cycle. Further AC impedance measurements reveal the sample produced by glucose shows the lowest charge transfer resistance.
LiFePO4 material was synthesized at 650°C in an N2 atmosphere using a sol-gel method. This material showed a well developed XRD pattern (orthorhombic structure, Pnma) without peaks at 2θ=41°, indicating the absence of FeP or metallic Fe2P impurities. The Li/LiFePO4 cell showed a high initial discharge capacity of more than 140mAh/g and no capacity decrease until the 50th cycle (>99.0%).
Due to the high stability and potential characteristics to the economical and environmental, the Li3V2(PO4)3increased the global concern on the polyanionic materials. In this work, we using Li2CO3, V2O5, NH4H2PO4 and PEG as raw materials to compared the flow phase reaction and high temperature solid state synthesis of lithium vanadium phosphate composites. The results of this study can be considered in making decision which conditions of achieved precipitation of carbon source can be efficiently applied in a real Electrochemical performance manufactory. The obtained results indicated that using Glucose as carbon source, and calcined at 800 °C, 0.1C rate current conditions, high temperature solid state sintering of lithium vanadium phosphate composites for the first time following a discharge capacity of 119.31mAh/g, which has a good reusability performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.