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In this study, activated carbon was prepared after pyrolysis and activation of shrimp shells. The effects of different impregnation ratios and temperatures on the physical and chemical properties of activated carbon were investigated. The physical and chemical properties of different activated carbons were characterized by N2 adsorption–desorption, scanning electron microscopy, and X-ray diffraction. The results show that at a pyrolysis temperature of 400°C, the activated carbon with a C/ZnCl2 ratio of 1/2 has the maximum specific surface area and pore volume of 1,536.3 m²/g and 0.83 cm³/g, respectively. The experimental results show that with the increase of pH value, the adsorption capacity of activated carbon will gradually decrease, indicating that acidic conditions are more favorable for nitrate adsorption. The maximum adsorption capacity was of the carbon achieved at about 5.58 mg/g at such conditions. The pseudo-first-order kinetic model fits well with the nitrate adsorption kinetics date with a high determination coefficient (R² > 0.95), while both the Freundlich and Langmuir isothermal model fit the experimental data well (R² > 0.95). Also, the influence of the coexisting anions on the adsorption performance of activated carbon has also been studied, the inhibitory effect of coexisting anions on the adsorption of nitrate on activated carbon is from high to low: CO3 2– > SO4 2– > Cl–. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel photocatalyst (D-cys/Au NPs-TiO 2 , DAT) was successfully fabricated. • The highest degradation rate of DAT for chlorpyrifos reaches 96.7%. • The degradation pathway of OPPs involved oxidation of P = S, cleavage of O-P and C-O. • This study provides a potential approach to remove OPPs in fruits and vegetables. The widespread use of organophosphorus pesticides (OPPs) in foods, poses a serious threat to human and environmental health, it is crucial to develop methods that can efficiently degrade residual OPPs. Herein, a chiral TiO 2 photocatalyst was developed by modification TiO 2 with D-cys/Au NPs (DAT) for the simultaneous degradation of four OPPs (chlorpyrifos, chlorpyrifos-methyl, malathion, and parathion) by natural light. The influence of D-Au NPs concentration on the degradation process was optimized, along with the initial pesticide concentration. Under optimal conditions, the photocatalytic degradation efficiencies of DAT for four OPPs were 96.7 %, 56.9 %, 42.6 %, and 49.2 %, respectively, after 12 h of natural light exposure. 12 degradation products of OPPs were identified, among which three products were identified for the first time. The degradation pathway revealed that the degradation of OPPs by DAT involves the oxidation of the P═S bond and the cleavage of the P-O bond and C-O bond. This study establishes a theoretical foundation for applying chiral TiO 2 nanomaterials for the photocatalytic degradation of OPPs in foods. [ABSTRACT FROM AUTHOR]

• A robust and powerful fluorescent sensor array R1SA using only a unique coumarin-pyridine compound R1 is reported. • R1SA can accurately discriminate 12 metal ion species in both aqueous solution and serum media. • R1SA was able to identify the unknown metal ion in serum samples with 100% accuracy. • R1SA was successfully applied to discriminate the mixtures of similar metal ions and the valence states of iron. The development of reliable methods for large scale discrimination of versatile metal ions is meaningful to avoid metal poisoning accidents and investigate their biological roles. Herein, a solvent directed strategy is reported for readily construction of a robust and powerful fluorescent sensor array R1SA for effective metal ion discrimination. The four sensors of R1SA were obtained by simply dissolving a unique coumarin-pyridine compound R1 in four different solvents, i.e., methanol, ethanol, acetonitrile and DMSO respectively. The sensing mechanism was based on the fact that R1 showed fluorescence responses towards various metal ions in a solvent directed manner. R1SA was able to generate distinct fluorescence response patterns for 12 kinds of metal ions including Cd2+, Co2+, V3+, Sn2+, Fe3+, Cr3+, Hg2+, Mn2+, Cu2+, Bi3+, Pb2+, and Ag+. It was able to discriminate these 12 metal ion species reliably in both aqueous solution and serum media, and identify the unknown metal ion in serum samples with high accuracy. Moreover, R1SA was also successfully applied to discriminate metal ion mixtures of Sn2+/Pb2+, Cd2+/Hg2+ and the valence states of iron in water and 5 % serum media, indicating that it can be considered as a practical tool for investigating the biological roles of iron. [ABSTRACT FROM AUTHOR]

Abstract: The characterization of impurities present in vertilmicin by liquid chromatography (LC) coupled with mass spectrometry (MS) is described. A reversed phase (RP)-LC method using a C18 column resistant to basic pH with an alkaline (pH 11) aqueous mobile phase was developed and coupled to MS with an electrospray ionization (ESI) source in the positive ion mode which provides MS n capability. In total, 18 impurities were detected in a commercial sample. Eleven impurities described in this work were newly identified. [Copyright &y& Elsevier]

Abstract: A reversed phase (RP)-LC method using a C18 column resistant to basic pH and an alkaline (pH 10) aqueous mobile phase was developed and coupled to MS with an electrospray ionization (ESI) source in the positive ion mode which provides MS n capability. In total, 26 impurities were detected in a commercial sample. The structures of the impurities were proposed based on comparison of their fragmentation patterns with those of the available reference substances, the synthetic route and literature data. Starting material and its residual impurities, intermediates, synthetic by-products and degradation products were the main sources of those impurities. 14 impurities described in this work were newly identified. [Copyright &y& Elsevier]

Abstract: The characterization of impurities present in micronomicin sulfate injection by liquid chromatography (LC) coupled with mass spectrometry (MS) is described. A reversed phase (RP)-LC method using a C18 column resistant to an alkaline (pH 11) aqueous mobile phase was developed and coupled to MS with an electrospray ionization (ESI) source in the positive ion mode which provides MSn capability. A total of thirty six impurities were detected in commercial samples: five impurities were identified by comparison of their fragmentation patterns with those of available related substances, eleven of them were identified in accordance with relevant literature, while the other twenty impurities were newly identified using the MS/MS spectra of the available related reference substances as interpretative templates combined with knowledge of the nature of functional group fragmentation behaviors. This work was applied to evaluate the quality of micronomicin sulfate injection from different manufacturers. [Copyright &y& Elsevier]