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ObjectiveA method for the preparation and certification of the reference material of tenuazonic acid(TeA) and tentoxin (TEN) in wheat flour was developed.MethodsThe reference material of TeA and TEN in wheat flour was prepared from grain which naturally contaminated alternaria toxins, characterizated with national standard regulation.ResultsThe reference materials of TeA and TEN in wheat flour which contains two values were developed. The reference materials were approved the second class of National Certified Reference Materials [GBW(E) 100547 and GBW(E) 100548].ConclusionThe reference materials are currently the only National Certified Reference Materials of wheat flour that naturally contaminate TeA and TEN. The reference materials provides important method ological reference for the development of matrix reference materials with new mycotoxins in grain in China.

Using gas chromatography–tandem mass spectrometry and electrospun nanofibrous membrane, we developed and validated a simple, rapid, and sensitive methodology for quantifying eugenol residues in fish tissue and water samples. Fish tissue extract and water samples (315 samples) collected from three southeastern China provinces (Shanghai, Zhejiang, and Fujian), originating from eight provinces of Zhejiang, Jiangsu, Shandong, Guangdong, Fujian, Anhui, Shanghai, and Jiangxi, from April 2021 to April 2023 were filtered with an electrospun nanofiber membrane, extracted with trichloromethane/n-hexane, and directly concentrated to dry after simple purification. An internal standard of p-terphenyl in n-hexane and 5-µL injection volumes of the solutions was used to analyze eugenol via internal calibration with a minimum concentration of 0.5 µg/L in water samples and 0.1 µg/kg in aquatic product samples. The highest amount of eugenol was detected in Fujian province, possibly due to the higher temperature during transportation, while the lowest amount was found in Shanghai, which mainly uses temporary fish-culture devices. This is a fast, inexpensive, and effective method for testing large quantities of fish water and meat samples. [ABSTRACT FROM AUTHOR]

Greigite (Fe3S4), which have ferromagnetic in inverse thiospinel (AB2S4), is widely researched to use an adsorbent and biomedical field because non-toxicity and abundant in nature. Iron-based materials are known to have a high theoretical capacity because of their multivalent state including redox pairs, but still suffer from collapse and aggregate during the charge/discharge process. Here, the synthesized Fe3S4 nanosheet structure materials wrapped with reduced graphene oxide (Fe3S4NSs@rGO) were used as an anode electrode material for sodium-ion batteries (SIBs). The nano-sheet structure facilitates ion diffusion through expanded surface area, and rGO can effectively improve electrochemical conductivity and structure stability. As-prepared Fe3S4NSs@rGO were used as a host material to insert Na-ion via a conversion process, and the stabilized structure maintains the high capacity and long cycle performance. Thus, the Fe3S4NSs@rGO deliver a reversible capacity of 950 mAh g−1 after 200 cycles at a current density of 1A g−1 and 524 mAh g−1 after 400 cycles at a current density of 2A g−1, which is much higher than reported materials.

The filtration characteristics of low oil saturation reservoirs are obviously different from that of conventional reservoirs. The development performance and the influence factors for low oil saturation reservoirs were studied using laboratory large model physical modeling and reservoir numerical simulation, to match and establish the empirical formula of water cut variation. In the numerical stimulation process, the effect of threshold pressure on filtration for low permeability reservoirs was considered, which made the results more realistic. There wasn't a period of oil recovery without water for low oil saturation reservoirs; the water cut increased rapidly at the beginning, and dropped slightly before the period of oil production with stable water cut. The higher the initial water saturation, the shorter the production time with stable water cut. Recovery changed greatly with the injection/production pressure gradient when the injection/production pressure gradient was close to the pseudo threshold pressure gradient. Recovery changed little, even no change, with the injection/production pressure gradient when the injection/production pressure gradient was far larger than the pseudo threshold pressure gradient. There was a positive correlation between recovery degree and water injection rate when the injection/production pressure gradient was less than the pseudo threshold pressure gradient. Key words: low oil saturation reservoir, low permeability reservoir, pseudo threshold pressure gradient, filtration