Determination of lead (II) ion by highly selective and sensitive lead (II) membrane electrode based on 2-(((E)-2-((E)-1-(2-hydroxyphenyl) methyliden)hydrazono)metyl)phenol

A PVC (poly vinyl chloride) membrane electrode for lead ion based on 2-(((E)-2-((E)-1-(2-hydroxyphenyl)methyliden)hydrazono)metyl)phenol (HMHMP) as a membrane carrier was prepared. This electrode exhibited linear response with Nernstian slope of 29.2?±?0.2?mV per decade within the concentration range of 2.0?×?10^?7–1.0?×?10^?1?M lead ion. The limit of detection, as determined from the intersection of the extrapolated linear segments of the calibration plot, was 8.0?×?10^?8 M. The electrode exhibited high selectivity for Pb (II). The response time of the electrode was about 5–10?s for different concentrations. The electrode is suitable for use in aqueous solutions in a pH range of 5.0–7.5. It was used as an indicator electrode in a titration of Pb (II) with chromate at constant pH. This electrode was used for the determination of lead in ore samples, and the results were in agreement with those obtained with an atomic absorption spectroscopy (AAS) method. Also lead selective electrode was used for monitoring of lead in spiked samples of the Zayanderud River and waste water by the potentiometry technique.     

Introducing Organic Gas Steam-Liquid Extraction as a New Preconcentration Method for Benzene,Toluene, Ethylbenzene and Xylene Determination in Water Samples by Gas Chromatography-Flame Ionization Detection

Journal of Analytical Chemistry - In this study, for the first time, the organic gas steam-liquid extraction by a special hand-made cell was used as a simple and inexpensive preconcentration...     

Energy and exergy analysis of a novel turbo-compounding system for supercharging and mild hybridization of a gasoline engine

Journal of Thermal Analysis and Calorimetry - Number of hybrid vehicles has increased around the world significantly. Automotive industry is utilizing the hybridization of the powertrain system to...     

Conductometric study of complex formation between benzylbisthiosemicarbazone and metal cations in acetonitrile,dimethylformamide, and their binary mixtures

We report on conductometric study of complexation between benzylbisthiosemicarbazone [(2E,2′E)-2,2′-(1,2-diphenylethane-1,2-diylidene)bis(hydrazine-1-carbothioamide)] with Zn²⁺, Cr³⁺, Co²⁺, and Ni²⁺ cations at different temperatures in acetonitrile-dimethylformamide binary solvents of varied composition. The equilibrium constant and standard thermodynamic parameters (Δ_c H ⁰ and Δ_c S ⁰) of the complexes formation have been determined and found to be dependent on the binary solvent composition, the metal ion nature, and temperature.     

A Silver Bite: Crystalline Heterometallic Architectures Based on Ag–π Interactions with a Bis‐Dipyrrin Zinc Helicate

An unprecedented mode of assembly of helical motives and Ag^I ions in the crystalline state is described. The combination of a Zn^II helicate based on a 2,2′‐bisdpm bearing peripheral benzonitrile moieties with AgX salts, leads to the formation of a tetranuclear core containing Ag–π interactions. Depending on the coordinating ability of the X^? anion and the solvents used, the tetranuclear complex self‐assembles into coordination polymers of varying dimensionality. From the sequence of coordination events (Ag–π or Ag–peripheral site), one may envisage two possible construction scenarios. However, the Ag–π as primary event seems reasonable owing to the rather weak binding propensity of the nitrile group and the chelating nature of the π‐clefts.     

Multiple functions of microfluidic platforms: Characterization and applications in tissue engineering and diagnosis of cancer

Microfluidic system, or lab-on-a-chip, has grown explosively. This system has been used in research for the first time and then entered in the clinical section. Due to economic reasons, this technique has been used for screening of laboratory and clinical indices. The microfluidic system solves some difficulties accompanied by clinical and biological applications. In this review, the interpretation and analysis of some recent developments in microfluidic systems in biomedical applications with more emphasis on tissue engineering and cancer will be discussed. Moreover, we try to discuss the features and functions of microfluidic systems.     

Magnetic carbon nanotube as a highly stable and retrievable support for the heterogenization of sulfonic acid and its application in the synthesis of 2-(1H-tetrazole-5-yl) acrylonitrile derivatives

In the present study, a novel magnetic carbon nanotube functionalized by chlorosulfonicacid (Fe₃O₄-CNT-SO₃H) with nanotube morphology decorated by the spherical nanoparticles was prepared, characterized and introduced as a retrievable magnetic heterogeneous nanocatalyst for green synthesis a variety of 2-(1H-tetrazole-5-yl) acrylonitrile via multicomponent domino Knoevenagel condensation/ 1,3-dipolar cycloaddition reaction between aromatic aldehydes, malononitrile, and sodium azide under solvent free conditions. The catalyst was magnetically separated from the reaction system by an outer magnetic force and recycled up to five runs without a remarkable loss in its efficiency. The as-preparedacidic magnetic nanocomposite was characterized by different techniques inclusive Fourier transform infrared, thermogravimetric analysis, energy dispersive X-ray, field emission scanning electron microscopy, X-ray diffraction, vibrating sample magnetometry, CHNS elemental analysis, and acid-base titration. Easy workup, affordability, elimination of volatile and toxic solvents, and high yield of products are some merits of this protocol.     

Overcoming acid–base copolymer neutralization using mesoporous carbon and its catalytic activity in the tandem deacetalization–Knoevenagel condensation reaction

Research on Chemical Intermediates - Acid–base copolymer materials are of considerable interest because of their fundamental implications for acid–base bifunctional catalysis...     

4-Oxobenzo[d]1,2,3-triazin-pyridinium-phenylacetamide derivatives as new anti-Alzheimer agents: design,synthesis, in vitro evaluation,molecular modeling,and molecular dynamic study

Structural Chemistry - A new series of 4-oxobenzo[d]1,2,3-triazin-pyridinium-phenylacetamide hybrids 8a–p was designed, synthesized, and screened as the potential cholinesterase inhibitors...