Removal of phenol by heterogenous photo electro Fenton-like process using nano-zero valent iron

A review on spectroscopic methods for determination of nitrite and nitrate in environmental samples

A simple hydrogen peroxide biosensor based on a novel electro-magnetic poly(p-phenylenediamine)@Fe3O4 nanocomposite.

This review represents a comprehensive attempt to summarize and discuss various sensing applications of iron oxide nanoparticles (NPs), which have attracted a great deal of attention over recent years because of their easy preparation, biocompatibility, nontoxicity, and broad range of biomedical applications. We review the application potential of nanomagnetite based amperometic sensors possessing an intrinsic enzyme mimetic activity similar to that found in natural peroxidases. In addition, we discuss the properties and applications of enzymatic sensors exploiting glucose oxidase, tyrosinase, and other enzymes for sensing a variety of important biomedical species. Among iron oxide-based nanocomposites, we highlight the use of Fe3O4@Au hybrids for designing new electrochemical aptasensors with unique versatility for binding diverse targets, including proteins and peptides. Similarly, sensing applications of composites of iron oxide NPs with graphene derivatives and carbon nanotubes are reviewed. A large p...

Nanocrystalline Iron Oxides, Composites, and Related Materials as a Platform for Electrochemical, Magnetic, and Chemical Biosensors

Extended research on the design and development of a smart nitrate sensor for monitoring nitrate concentration in surface and groundwater are reported in this paper. The developed portable sensing system consists of a planar interdigital sensor, associated electronics, instrumentation, and electrochemical impedance spectroscopy based analysis. The system is capable of measuring nitrate concentrations in the range of 0.01–0.5 mg/L in ground and surface water. This paper extends our earlier work by including a temperature compensation capacity within the sensor. WiFi-based Internet of Things (IoT) has been included, making it a connected sensing system. The system is capable of sending data directly to an IoT-based web server, which will be useful to develop distributed monitoring systems in the future. The developed system has the potential to monitor the impact of industrial, agricultural, or urban activity on water quality, in real time.

A Temperature Compensated Smart Nitrate-Sensor for Agricultural Industry

A simple, rapid and sensitive spectrophotometric method is described for the determination of hydrogen peroxide using toluidine blue as a reagent. The proposed method is based on the liberation of iodine in acidic medium equivalent to the amount of hydrogen peroxide present. The liberated iodine bleaches the blue color of toluidine blue and is measured at 628 nm. The decrease in absorbance is directly proportional to hydrogen peroxide concentration and obeys Beer’s law in the range 0.2 × 10–6 –14 × 10−6 mol L−1. The molar absorptivity, sandel’s sensitivity, detection limit and quantitation limit of the method were found to be 1.82 × 104 L mol−1 cm−1, 2.01 × 10−9 mol L−1, 1.41 × 10−6 mol L−1 and 4.28 × 10−6 mol L−1 respectively. The results of analysis of the proposed method are compared favorably with those from a reference method.

Spectrophotometric determination of hydrogen peroxide in water and cream samples.

A simple, rapid spectrophotometric method for the determination of nitrite and nitrate in water, tablets and water samples have been developed Determination of nitrite is based on the reactions involving sulfanilic acid with methyl anthranilate as the coupling agents and determination of nitrate is based on their reduction to nitrite in the presence of Zn/NaCl The produced nitrite is subsequently diazotized with sulfanilic acid then coupled with methyl anthranilate to form an azo dye which is measured at 493 nm The method is optimized for acidity, amount of reagents required and tolerance amount of other ions The range of linearity for sulfanilic acid-methyl anthranilate couple was found to be 02-80 µg/ml of nitrite with molar absorptivity be 103x10 4 Lmol -1 cm -1 and sandell ’ s sensitivity 45x10 -3 µg cm -2

A Spectrophotometric Method for the Determination of Nitrite and Nitrate

Geometric parameters of the title compound, C15H12BrN3O4, a Schiff base, are in the usual ranges. There are two mol­ecules in the asymmetric unit, differing in the dihedral angles between the aromatic rings and the central CO—NH—N=C unit. Furthermore, the Car—Car—O—CH3 torsion angles differ by almost 180°. The crystal packing is stabilized by N—H⋯O hydrogen bonds.

/pdf/2-bromo-5-methoxy-n-e-2-nitrophenyl-methylene-benzohydrazide-3ikg668oha.pdf

2‐Bromo‐5‐methoxy‐N′‐[(E)‐(2‐nitrophenyl)methylene]benzohydrazide

The geometric parameters of the title compound, C9H12N2S, are in the usual ranges. The thiourea group is almost perpendicular to the aromatic ring dihedral angle = 80.75 ( 7)degrees]. The crystal packing is stabilized by N-H center dot center dot center dot S hydrogen bonds linking the molecules into layers perpendicular to the c axis. Only two of the three amino H atoms are involved in hydrogen bonding.

/pdf/1-2-6-dimethylphenyl-thiourea-4fojfh9t4s.pdf

1-(2,6-Dimethylphenyl) thiourea

The crystal structure of the title compound, C14H10F2N2, is stabilized by C—H⋯F inter­molecular hydrogen bonds, which generate edge-fused R21(6)R32(15)R22(8)R32(17) ring motifs. The complete mol­ecule is centrosymmetric and almost planar.

K. Sunil

Papers

Spectrophotometric determination of hydrogen peroxide in water and cream samples.

A Spectrophotometric Method for the Determination of Nitrite and Nitrate

2‐Bromo‐5‐methoxy‐N′‐[(E)‐(2‐nitrophenyl)methylene]benzohydrazide

1-(2,6-Dimethylphenyl) thiourea

4‐Fluorobenzaldehyde [(E)‐4‐fluorobenzylidene]hydrazone