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In the first part of this research, zinc sulfide nanoparticle loaded activated carbon was synthesized by a simple and low cost procedure. Zinc sulfide nanoparticles were prepared, characterized and loaded on commercially available activated carbon. The zinc sulfide nanoparticle was characterized by UV-vis, SEM and XRD analysis. The objective of this study was to assess the suitability and efficiency of zinc sulfide nanoparticle loaded activated carbon (ZnS-NP-AC) for the removal of Methylene blue (MB) from aqueous solution. Adsorption studies were conducted in a batch mode and the influences of various operating parameters including pH, contact time, initial dye concentration, ZnS-NP-AC amount on the extent of MB adsorption were investigated in details. The adsorption equilibrium data were fitted well to the Langmuir model. The maximum MB adsorption capacity was found as 100 mg g−1 of adsorbent. To investigate the kinetic of adsorption, the time dependency of removal percentage of MB on ZnS-NP-AC was analyzed by various models such as, pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion kinetic. It was found that the adsorption follows pseudo-second-order kinetic with involvement of intraparticle model. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 535-542, 2013 [ABSTRACT FROM AUTHOR]

Abstract: A new method is described for the simultaneous preconcentration of trace metal ions. The method is based on the adsorption of Co2+, Ni2+, Cu2+ and Cd2+ ions on 2,4,6,8-tetra(2-hydroxyphenyl)-1,3,5,7(1,3)tetrabenzenzcyclooctaphane-14,16,34,36,54, 56,74,76-octol (salicylaldehyde calix[4] resorcinarenes) (new resorcinarenes derivative) modified on Amberlite XAD-16. The adsorbed analyte ions were eluted with 6mL 3M HCl in acetone solution, which then were determined by atomic absorption spectroscopy. The influences of the analytical parameters including pH, ligand amount and solid phase ingredient, eluting solution conditions and sample volume were investigated. Common coexisting ions did not interfere with the separation and determination. The preconcentration factor is 208. The sorbent exhibited excellent stability and its sorption capacity under optimum conditions has been found to be more than 60μg of ions per gram of sorbent. The relative standard deviation under optimum conditions is lower than 4.10%. The accuracy of the method was estimated by using different real samples. [Copyright &y& Elsevier]

Fluorescent chemical sensors to detect materials, by increasing fluorescence emission and absorption or by shutting down, because they are nondestructive, the ability to show decomposed concentrations, fast response, high accuracy have been considered and used. In this research, a chemical sensor was synthesized PbS functionalized with gelatin quantum dots for the determination of toxic bentazon (BTZN) one of the most problematic pesticides polluting in water samples, and extremely harmful to humans and animals even at low concentrations. The calibration curve was linear in the range of (0.05 to 200.0 ng mL -1 ). The current response was linearly proportional to the BTZN concentration with a R 2 ∼ 0.999. The standard deviation of less than (3%), and detection limits (3S/m) of the method (0.5 ng mL -1 , in time 50 s, 325 nm) were obtained for sensor level response PbS Quantum Dot-Gelatin nanocomposites sensor with (99%) which is below the U.S. Health Advisory level. The observed outcomes confirmed the suitability recovery and a very low detection limit for measuring the BTZN. The method fluorometric introduced to measure BTZN in water samples was used and can be used for in different intricate matrices, the chemical PbS Quantum Dot-Gelatin nanocomposites sensor made it possible as an excellent sensor with good reproducibility.

The present work describes a method (SWASV) techniques for measure of tartrazine color a harmful compound present in real samples, and the extremely harmful to humans and animals even at low concentrations using G-C 3 N 4 nanosheets sensor. Here, we report the use of an electrochemical approach for analytical determination of toxic tartrazine that takes 150 s. The calibration curve was linear in range of the (0.02-18.0 µmol L -1 ). The current response was linearly proportional to the tartrazine concentration with a R 2 ∼ 0.999. We demonstrated a sensitivity a limit of detection of (0.022 µmol L -1 ). Finally, sensor nanosheets G-C 3 N 4 /CPE introduced to measure toxic tartrazine in different drink and foodstuff samples was used and the chemical nanosheets G-C 3 N 4 /CPE sensor made it possible as an excellent sensor with reproducibility for determination other samples.

In this research, g-C 3 N 4 nanosheets were facilely fabricated by thermal polymerization and then exfoliated into ultrathin nanosheets through ultrasonication in water media. Low-cost C-N nanosheets prepared by melamine possessed a highly π-conjugated structure and fluorescence property. In the present study, the g-C 3 N 4 nanosheet was used as a switch-off fluorescence sensor for rapid and sensitive sensing of metronidazole in biological fluids. These nanosheets were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. The fluorescence of the solution of the g-C 3 N 4 nanosheets was quenched effectively by metronidazole through two mechanisms: fluorescence resonance energy transfer and the formation of a donor-acceptor charge-transfer complex between π-electron rich donors. Under optimal conditions, the detection linear range for metronidazole was found to be from 0.01 to 0.10μgml -1 , with a limit of detection (LOD) of 0.008μgml -1 which can cover standard range of metronidazole in real samples. Moreover, the proposed method has offered a green, rapid, and sensitive probe for quantitative determination of metronidazole in drug and biological fluids., (Copyright © 2017. Published by Elsevier B.V.)

A sensitive, simple and novel method was developed to determine thiram fungicide in water and plant samples. This method was based on the interaction between gold nanoparticles (AuNPs) and thiram fungicide followed by increasing of the Resonance Rayleigh scattering (RRS) intensity of nanoparticles. The change in RRS intensity (∆IRRS) was linearly correlated to the concentration of thiram over the range of 1.0-200.0µgL(-1). Thiram can be measured in a short time (4min) without any complicated or time-consuming sample pretreatment process. Parameters that affect the RRS intensities such as pH, concentration of AuNPs, standing time, electrolyte concentration, and coexisting substances were systematically investigated and optimized. Interference tests showed that the developed method has a very good selectivity and could be used conveniently for the determination of thiram. The limit of detection (LOD) and limit of quantification (LOQ) were 0.3 and 1.0µg L(-1), respectively. Relative standard deviations (RSD) for 20.0 and 80.0µg L(-1) of thiram were 3.0 and 1.1, respectively. Possible mechanisms for the RRS changes of AuNPs in the presence of thiram were discussed and the method was successfully applied for the analysis of spiked real water samples and fresh plant samples such as tomato and cucumber., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A sensitive, simple and novel method was developed to determine 2-mercaptobenzothiazole (2MBT) in water samples. This method was based on the interaction between gold nanoparticles (AuNPs) and 2MBT followed by increasing of the resonance Rayleigh scattering (RRS) intensity of nanoparticles. The change in RRS intensity (ΔIRRS) was linearly correlated to the concentration of 2MBT over the ranges of 5.0-100.0 and 100.0-300.0 μg L(-1). 2MBT can be measured in a short time (5 min) without any complicated or time-consuming sample pretreatment process. Parameters that affect the RRS intensities such as pH, concentration of AuNPs, standing time, electrolyte concentration, and coexisting substances were systematically investigated and optimized. Interference tests showed that the developed method has a very good selectivity and could be used conveniently for determination of 2MBT. The limit of detection (LOD) and limit of quantification (LOQ) were 1.0 and 3.0 μg L(-1), respectively. Relative standard deviations (RSD) for 20.0 and 80.0 μg L(-1) of 2MBT were 1.1 and 2.3, respectively. Possible mechanisms for the RRS changes of AuNPs in the presence of 2MBT were discussed and the method was successfully applied for the analysis of real water samples., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A simple and relatively fast approach for developing a solid phase extraction has been described and used for determination of trace quantities of some heavy and transition metal ions with sodium dodecyl sulfate (SDS)-coated poly vinyl chloride (PVC) modified with bis(2-hydroxyacetophenone)-1,4-butanediimine (BHABDI) ligand. The adsorbed ions were stripped from the solid phase by 10 mL of 3M nitric acid as eluent. The eluting solution was analyzed for metals content (cadmium, chromium, cobalt, copper, lead and zinc) by flame atomic absorption spectrometry (FAAS). The main factors such as pH, amount of ligand and PVC, amount and type of surfactant, and condition of eluting solutions on the sorption recovery of metal ions have been investigated in detail. The relative standard deviation was found in the range of 1.0-3.2% for 0.2 microg mL(-1)of metals ions. After optimization of the extraction condition and the instrumental parameters, a detection limit was found to be in the range of 1.2-3.1 microg L(-1), with enrichment factor of 50 was achieved. The method was successfully applied for the determination of these metals contents in real samples with satisfactory results.