A technique for the mass fraction evaluation of the basic substance in dialkyl methylphosphonate samples by automatic potentiometric titration is presented. A comparison was made with a certified technique of visual titration. Several advantages of our method are shown: the ability to automate analysis, a reduced sample weight, a constant and precise volume of a titrant drop, a reduced detection time, avoiding the use of chemical indicators, an improved precision of analysis.
The method of atomic absorbing spectrometry (AAS) determined the content of mobile forms of copper, nickel and zinc, and total content of mercury and arsenic in the soil samples selected in a residential zone Samara, and copper in the ventilating emissions. For soils the sample preparation stage contribution to the general error of analytical definition is estimated. For ensuring correctness definition of the content of copper in the ventilating emissions the correction coefficient cons idering existence of a systematic mistake is calculated.
The method of atomic absorbing spectrometry (AAS) determined the content of mobile forms of copper, nickel and zinc, and total content of mercury and arsenic in the soil samples selected in a residential zone Samara, and copper in the ventilating emissions. For soils the sample preparation stage contribution to the general error of analytical definition is estimated. For ensuring correctness definition of the content of copper in the ventilating emissions the correction coefficient considering existence of a systematic mistake is calculated.
Novel complex of terbium (III) with aromatic monoketone – 2,6-dibenzylidenecyclohexanone – has been synthesized. Its uncharacteristic luminescent properties have been studied using quantum chemical calculations and lumiscent spectroscopy.
Examined the condition of the main and neutral ?-amino acids in aqueous media. Graphs of the distribution of ionized forms of histidine and alanine with varying pH. Pakistan the possibility of pH –metric selective determination of histidine in mixtures of neutral amino acid with a glass indicator electrode. The error does not exceed 7%
A review of the literature on the phenomenon of aging (a significant drop in viscosity over time) of acidic chitosan solutions is given. A study was made on acetic acid (2%) solutions of chitosan of two viscosity-average molecular weights (200 and 46 kDa) by ion probing (addition of a KI solution). It has been indirectly confirmed that the motion of the probing ions in an electric field disturbs part (about a quarter) of the average macromolecule rather than the whole one.
The possibility of converting the biomass to products of petrochemical synthesis is shown. The analysis of the development of the synthesis of catalysts for production of motor fuels from bioethanol is carried out. By varying the composition of the catalysts and the process conditions can be synthesized gasoline range hydrocarbons, ethylene, aromatic hydrocarbons. A scheme for the conversion of ethanol to hydrocarbons of various classes is discussed.
9-phenyl-4,5,6,7,8,9-geksagidrotetrazolo[5,1-b]quinazoline in solution undergoes reaggregation ent via an azide to form a positional isomer corner structure that is installed involving spectral methods (1H-NMR, IR -spectra), TLC, chromato-mass spectrometry.
The result of quantum-chemical studying of geometric characteristics for aromatic amine sulfoderivatives at MP2/6-31G(d,p) as well as experimental and theoretical investigation of IR spectra of these compounds are presented. It was shown for triphenylamine (TPhA) and triphenylamine-4-sulfonic acid (TPhASA) that theoretical vibrational spectrum was in good agreement with experimental data.
Application of multivariate regression methods for catalimetry simultaneous determination of iridium (IV) and rhodium (III) based on oxidation of N-methyldiphenylamine-4-sulphonic acid by periodations in weak acid medium was investigated. The data structure of the kinetic measurement was studied with Principal Component Analysis, it was found that the distribution of the samples corresponds to an increase in the total concentration of the catalysts of the PC1 and change the concentration ratio Ir: Rh on PC2.
