Химия

The oxidation of triphenylamine-4-sulphonic acid (TPASA) by hydrogen peroxide in presence of horseradish peroxidase (HRP) in weak acid medium and after incorporation of TPASA in polymeric hydrogel matrix of polyurethane (type D4) was investigated by spectrophotometry. The stability of TPASA product enzymatic oxidation under variation of reaction condition (reagents concentration, acidity) was studied. The optimum condition was selected and the possibility of HRP detection in sensor plate was shown with limit of detection 0.3•10-4 U/mL.

Cefotaxime is a cefalosporin antibiotic possessing a high efficiency at curing severe bacterial infections. For the determination of cephalosporin antibiotics in different objects, spectroscopic, chromatographic, electrochemical methods, immunoassay, etc. are used, which demand for expensive devices and organic solvents. Potentiometric sensors let one expressively detect cefalosporin antibiotics in small samples without previous sample preparation.

Metal-alginate complexes (especially, lanthanide gels) are particularly interesting for medical and biological analysis due to their luminescent properties upon UV light excitation. Unfortunately, synthesis and further physical and chemical studies of such complexes is inhibited by their high cost. However, this problem can be solved by using quantum chemical methods to predict potential properties of lanthanide alginates based on the results of their geometry optimization and electronic structure calculation.

Was done the studie of activity zeolite-containing catalyst Cr2О3 +Bi2О3 /ZSM-5 and technical catalyst SI-2, also they combained action in process of conversion of n-hexane at lay-by-layers download. In the process of conversion n-hexane on Cr2О3 +Bi2О3 /ZSM-5 catalyst prevails reaction of cracking and destroy of n-hexane to two symmetric molecule of propane (51,4%). Lay-by-layers download of Cr2О3 +Bi2О3 /ZSM-5 and SI-2 catalysts with high conversion nhexane to achieve a lot of contents iso-hydrocarbons in products of conversion with 200 oC.

Cefuroxime axetil is a cephalosporin antibiotic of the second generation, it is used in the sequential therapy of patient with sinusitis, community-acquired pneumonia, and other infectious somatic pathologies. For the determination of cephalosporin antibiotics in different objects, spectroscopic, chromatographic, electrochemical methods, immunoassay, etc. are used, which demand for expen- sive devices and organic solvents. Potentiometric sensors let one expressively detect cefalosporin antibiotics in small samples without previous sample preparation.

The optical properties of noble metal nanoparticles feature the pres- ence of a pronounced resonance band in the visible light spectrum, called the surface plasmon resonance band. The influence of local surface plasmons on the dynamics of singlet–triplet energy transfer in the donor–acceptor pair is the subject of recent active studies by analysts in connection with the prospective using of nanoparticles in optosensorics and the opportunity of significant improvements of the metrological characteristics of analytical techniques.

Synthetic azodyes are widely used in paint, textile, plastic, and food, beverage, and leather, cosmetic, pharmaceutical and paper industries to make products more visually attractive to consumers. Therefore, they are also the components of waste waters and should be removed due to their potential risk to human health. Many techniques have been employed to eliminate dyes from waste water and do to preconcen- tration before analysis in food or beverage objects.

In living nature, of significance is lipid peroxidation caused by highly- reactive oxygen-containing species. Hydroperoxide anion –OOH represents a protolytic kind of hydrogen peroxide H2O2 – one of active forms of oxygen, – and a precursor of hydroperoxyradical •OOH – another one. The work is aimed at the investigation of spa- tial and electronic structure of hydroperoxide anion.

The experimental study of solubility of helium in propan-2-ol at high pressures and temperatures was performed. The following values of Henry’s law constants for the solution of helium in propan-2-ol were obtained: 168,7 ± 6,3 MPa at 480 К, 341,2 ± 13,6 MPa at 420 К and 602,0 ± 43,5 MPa at 360 К.

The phase diagrams of the ternary systems potassium carbo- nate+water+hydrocarbon (toluene, n.dodecane) at 25°С were first studied by means of the methods of sections and isothermal titration. The phase diagrams of both systems belong to those of ternary systems with salting-out of the binary heterogeneous system. Potassium carbon- ate sesquihydrate is the solid phase of monotectic equilibrium. Nine tie lines were drawn on the delamination field of the phase diagram of each ternary system.