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Abstract The synthesis of morphology‐controlled carbon‐coated nanostructured LiFePO4 (LFP/Carbon) cathode materials by surfactant‐assisted hydrothermal method using block copolymers is reported. The resulting nanocrystalline high surface area materials were coated with carbon and designated as LFP/C123 and LFP/C311. All the materials were systematically characterized by various analytical, spectroscopic and imaging techniques. The reverse structure of the surfactant Pluronic® 31R1 (PPO‐PEO‐PPO) in comparison to Pluronic® P123 (PEO‐PPO‐PEO) played a vital role in controlling the particle size and morphology which in turn ameliorate the electrochemical performance in terms of reversible specific capacity (163 mAh g−1 and 140 mAh g−1 at 0.1 C for LFP/C311 and LFP/C123, respectively). In addition, LFP/C311 demonstrated excellent electrochemical performance including lower charge transfer resistance (146.3 Ω) and excellent cycling stability (95 % capacity retention at 1 C after 100 cycles) and high rate capability (163.2 mAh g−1 at 0.1 C; 147.1 mAh g−1 at 1 C). The better performance of the former is attributed to LFP nanoparticles (

The synthesis of morphology-controlled carbon-coated nanostructured LiFePO4 (LFP/Carbon) cathode materials by surfactant-assisted hydrothermal method using block copolymers is reported. The resulting nanocrystalline high surface area materials were coated with carbon and designated as LFP/C123 and LFP/C311. All the materials were systematically characterized by various analytical, spectroscopic and imaging techniques. The reverse structure of the surfactant Pluronic® 31R1 (PPO-PEO-PPO) in comparison to Pluronic® P123 (PEO-PPO-PEO) played a vital role in controlling the particle size and morphology which in turn ameliorate the electrochemical performance in terms of reversible specific capacity (163 mAhg-1 and 140 mAhg-1 at 0.1 C for LFP/C311 and LFP/C123, respectively). In addition, LFP/C311 demonstrated excellent electrochemical performance including lower charge transfer resistance (146.3 Ω) and excellent cycling stability (95% capacity retention at 1 C after 100 cycles) and high rate capability (163.2 mAhg-1 at 0.1 C; 147.1 mAhg-1 at 1 C). The better performance of the former is attributed to LFP nanoparticles (<50 nm) with a specific spindle-shaped morphology. Further, we have also evaluated the electrode performance with the use of both PVDF and CMC binders employed for the electrode fabrication. [ABSTRACT FROM AUTHOR]

Quantitative determination of targeted and untargeted pesticide residues from food products is very important for the assessment of safety of the food products. In the present work, a simple, selective and sensitive method based on liquid chromatography atmospheric pressure chemical ionization high energy collisional dissociation high-resolution tandem mass spectrometry (LC-APCI-HCD-HRMS/MS) for quantification of 19 priority organophosphorus and carbamate pesticides and 10 untargeted pesticides from coconut milk samples was developed and validated. The pesticide residues were extracted by solvent partition followed by dispersive solid-phase extraction clean-up and quantified by LC-APCI-HRMS/MS technique. The method showed the linearity for targeted pesticides in the range of 0.5-1000 ng/g with a limit of detection of ranging 0.5-5 ng/g and limit of quantification of ranging 1-10 ng/g measured at 3:1 and 10:1 signal to noise ratios, respectively. The untargeted pesticide residues were quantified by the response factor method. The method was validated for intraday and interday precision, which was less than 15%. The recovery of the analytes varied between 82 and 117%, and the developed method was applied for the analysis of the coconut milk samples. The analyzed samples showed the presence of quinalphos, malathion, and methiocarb at concentrations of 4.55, 5.54, and 206.99 ng/g., Competing Interests: Declaration of Competing Interest The author has declared no conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Rationale: Fruit is generally ripened after harvesting using artificial ripeners such as ethylene, calcium carbide, and ethephon (2-chloroethylphosphonic acid), which can release some residues into the fruits. These residues must be within the maximum levels described in various international standards. The presence of the residues of artificial ripeners must be verified using sensitive and selective detection methods., Methods: The residues of ethephon and vinylphosphonic acid (VPA) were extracted from the pulp of sapota fruit using acetone, and the extract was treated with MgSO 4 to remove residual water. The extract was subjected to dispersive solid-phase extraction cleanup using DSC-6S sorbent and graphitized carbon black mix, and the cleaned sample was evaporated to dryness and reconstituted in ether containing diazomethane. The analytes were quantitatively identified using gas chromatography/mass spectrometry., Results: The developed method was observed to be linear in the concentration range of 1-5000 ng/g, and the limits of detection and quantification of the method were 1 and 2 ng/g, respectively, for both ethephon and VPA residues. The inter-day and intra-day precision was below 15%. The developed method was used for the quantification of ethephon residues from sapota fruit ripened with 100, 200, 500, 1000, 5000, and 10 000 mg/L solutions of ethephon, and ethephon residues were detected in the pulp samples up to a concentration of 5 ng/g. VPA residues were not detected in the fruit pulp; however, the washing solution of fruit ripened with a 10 000 mg/L ethephon solution showed VPA residues., Conclusions: The validated method exhibited high sensitivity for the analytes with a limit of quantification of 2 ng/g, which is lower than the described maximum residue level of 0-5 μg/g. The ethephon residues were below the maximum residue limits in the pulp of sapota fruit ripened with ethephon solutions up to 10 000 mg/L concentration., (© 2020 John Wiley & Sons, Ltd.)

The effect of post-harvest ripening by ethylene and calcium carbide was studied by headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) method. Sapota (sapodilla) fruits were ripened with ethylene gas, technical grade calcium carbide and pure calcium carbide ripeners and the samples were homogenised after complete ripening. The samples were subjected to HS-SPME-GC-MS and the obtained results showed the presence of various alcohols, aldehydes, acids, ketones and esters which were commonly present in the samples. The fruit samples ripened with technical grade calcium carbide showed the presence of 3,5-dimethyl-1,2,4-trithiolane isomers, which can be used as markers to identify sapota fruits ripened with technical grade calcium carbide. The technical grade calcium carbide contains divinyl sulphide which might have been transformed into the trithiolane isomers. These isomers were not observed in the fruits ripened with pure calcium carbide and also with ethylene gas. Hence the formation of trithiolane residues may be attributed to the presence of divinyl sulphide impurity present in calcium carbide and its conversion due to the action of ethylene releasing enzymes present in the fruits.

Objective: To assess the in vitro effects of various nalbuphine concentrations on viability and wound healing ability of corneal cells and potential drug transport through the corneal epithelium., Sample: Cultured canine and human corneal epithelial cells (CECs) and cultured canine corneal stromal fibroblasts., Procedures: CECs and stromal fibroblasts were exposed to nalbuphine (concentration of solutions ranged from 0% to 1.2%) for up to 30 minutes, and viability was assessed with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. A standard scratch test technique was used. Wound healing of CECs and stromal fibroblasts was evaluated following treatment with nalbuphine solutions < 0.1%. Liquid chromatography-mass spectrometry-mass spectrometry analysis was used to evaluate drug transport across a monolayer and a multilayer of human CECs., Results: A progressive decrease in viability was detected in canine CECs for all nalbuphine treatment groups, whereas treatment with only 0.5% or 1.2% nalbuphine significantly reduced corneal stromal fibroblast viability, compared with results for control cells. Within 24 hours, treatment with 0.1% nalbuphine solution significantly altered the healing rate of both canine CECs and stromal fibroblasts. Continuous increases in transport rates of nalbuphine were detected with time for both the monolayer and multilayer of human CECs., Conclusions and Clinical Relevance: In vitro, nalbuphine potentially could penetrate through corneal tissue, but it may cause damage to the corneal epithelium and stromal fibroblasts. Therefore, nalbuphine potentially may impair corneal wound healing.