Histopathology and cholinergic assessment of Pterocarya fraxinifolia on chicken embryo

There are no reports of toxicological studies of Pterocarya fraxinifolia. The leaves are used for fishing, which also an anesthetic agent. Currently, many drugs utilized in anesthesia practice are modified cholinergic transmission and acetylcholine esterase inhibitors; these are parts of anaesthetic pharmacy. Therefore, cholinergic assessment was surveyed in chicken embryo, which Pterocarya fraxinifolia extractes were injected in 0.1, 1 and 10 mg concentration at day 4 of incubation. Serum and brain cholinesterase were analyzed on day 20 of incubation. The signs were not due to the changes of cholinesterase activity. In histopathology examination, massive necrosis was observed in the spinal cord. Other tissues such as heart, kidneys, skeletal bones and muscles, trachea and lungs, digestive system and endocrine glands were completely developed. This data suggests that the spinal cord is a target organ of the bioactive component of this plant

A LC/UV/Vis method for determination of cyanocobalamin (VB12) in multivitamin dietary supplements with on-line sample clean-up

A HPLC-UV/Vis method using a two-column strategy with a switching valve for on-line sample cleanup was developed for the determination of cyanocobalamin (CN–Cbl/Vitamin B12) in multivitamin dietary supplement tablets. The method uses two columns: an Agilent Zorbax C8 (150 mm 4.6 mm, 5 mm particle size) reversed-phase column and a Waters Symmetry C18 (150 mm 4.6 mm, 5 mm particle size) reversed-phase column. Chromatographic separation was achieved using a programmed gradient mobile phase consisting of (A) 0.1% formic acid in water and (B) 0.1% formic acid in acetonitrile. Because of the low levels of Vitamin B12 in the samples, large injection volumes, and thus much interfering material, must be used to exceed the limit of quantitation (LOQ) by UV detection. A switching valve was used to divert most of these early eluting interfering materials to waste, effecting on-line sample clean-up without excessive sample preparation steps. The recovery of CN–Cbl in the method was 99.5% and the LOQ was 10 ng per injection. The method was successfully applied to the analysis of the NIST SRM 3280 multivitamin/multimineral dietary supplement tablet. The method is specific, precise, and accurate for the intended use. Compared to off-line sample clean-up procedures, it offers the advantage of being easier, more economical, and less time-consuming

Use of nanomaterials in the pretreatment of water samples for environmental analysis

The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe

Model-aided optimization and analysis of multi-component catalysts: Application to selective hydrogenation of cinnamaldehyde

Multi-component catalysts are widely used to exploit the component interactions with the aim to improve catalysis processes. This study applies a model-aided approach to determine the optimal compositions of carbon nanotubes (CNTs) supported Pt–Co–Fe catalysts for selective hydrogenation of cinnamaldehyde. The methodology integrates an iterative response surface methodology (RSM) for optimization, and global sensitivity analysis for interpreting the impact of components and their interactions on the achieved process yield. The RSM encapsulates the state-of-the-art space-filling experimental design, advanced data-based modeling, and model-aided optimization while considering prediction uncertainty. A high performance catalyst, 3.4%Pt-1.3%Co-2.6%Fe/CNT, is identified with 15 experiments, giving rise to 86.1% conversion, 86.4% selectivity and 74.4% yield. The sensitivity analysis identifies the role of the components and their interactions, which is consistent with reported literature results. For verification purpose, selected catalysts are characterized by using powder X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. Overall, this paper establishes the presented methodology as a powerful tool for design of multi-component catalysts

Solvatochromism Effect of Different Solvents on UV-Vis Spectra of Flouresceine and its Derivatives

ABSTRACT

Application of experimental design for extraction of BHA and BHT from edible vegetable oil and their determination using HPLC

The optimal conditions of liquid–liquid extraction of two synthetic phenolic antioxidants, BHA and BHT were investigated in five Iranian edible vegetable oil samples using the central composite design. Stepwise multiple linear regression method was used for construction of different models based on the experimental data. Optimum conditions for BHA and BHT were achieved using 3 ml of ethanolic solution containing (0.25% v/v) of glacial acetic acid, three extractions and a mixing time of 10 minutes