Chemistry

Quantum-chemical Research of the Mechanism of Reaction of an Acylating Butylmethylamine by Propionyl Chloride in the Presence of Lithium Hydride

In this paper is presented quantum-chemical research of the mechanism of reaction of an acylating butylmethylamine by propionyl chloride in the presence of lithium hydride. The estimate of two basic synthetic paths of an acylating butylmethylamine is made. Prereactionary complexes, transient states and reaction products are computed in program PRIRODA by a density functional theory (DFT) in approximation PBE and basis L1. Activation energies of reactions are computed. 

Effect of Oil Sludge Filler on Physico-chemical Properties of the Bituminous Composite Materials

An elemental composition and particle size distribution of the solid residue oil sludge are investigated, and a test samples series of a composite material is performed. The physico-chemical and operational properties of this material are investigated. Found that the characteris tics of the resulting material allow to use it in production of bituminous concrete for road construction.

Description of the Chemikal Interreacting in the Quaternary Mutual Sistem Li,K||F,MoO4 ,WO4

The quaternary mutual system Li,K||F,MoO4 ,WO4 was partitioned into the simplexes and described the chemical interaction by conversion method and by method of ion balance. The prediction of the crystallizing phases conducted on the basis of the partition and of the equations for the reactions of conversion lines and for the method of ion balance.

Influence of Some Factors on Phase Separation of System Sodium Dodecyl Sulfate – H2 O

The isothermal behavior of systems SDS – H2 O and SDS – H2 O – electrolytes has been investigated in the range 0–100 °C. The effect of the addition of sodium chloride, salicylic acid and sodium salicylate on the nature of phase transitions was shown. The viscosity of aqueous solutions of SDS (0–30 wt. %) was studied. The view about the nature of possible self-assembled structures in the systems was expressed.

Study Phase Triangles LiNO3 – NaNO3 – NaI, LiNO3 – KNO3 – KI and LiNO3 – RbNO3 – RbI Ternary Mutual Range Systems Li,M || I,NO3 (M – Na, K, Rb)

By differential scanning calorimetry (DSC) was first investigated experimentally determined complexes and phase characteristics of equilibrium points of the invariant three-phase triangles reciprocal systems of several Li,M || I,NO3 (M – Na, K, Rb). The compositions of eutectic (mol%) Li,Na || I,NO3 : (E1 ) NaNO3 – 42,5%, NaI – 5,0%, LiNO3 – 52,5% with a melting point of 178 °C. Li,K || I,NO3 (E2 ) LiNO3 – 44,0%, KI – 2,0%, KNO3 – 54,0% (mol) with a melting point of 117°.

Luminescent Determination of Polycyclic Aromatic Hydrocarbons on Cellulose Diacetate Matrix Modified by Surfactants

The ability of using cellulose diacetate (CDA) as matrix for luminescent determination of polycyclic aromatic hydrocarbons (PAH) in aqueous media was studied. PAH sorption was carried out on the example of pyrene from water solutions. Cellulose diacetate matrix was modified by anionic and cationic surfactants - sodium dodecylsulphate (SDS) and cetyltrimethylammonium bromide (CTAB). The comparative analysis of dependence of fluorescence intensity and polarity index of pyrene was carried out.

Simultaneous Determination of Fungicides ThIuram and Tebuconazole in Grain by High Performance Liquid or Micellar Electrokinetic Chromatography

Optimal conditions for separation and determination by HPLC or MEKC combined fungicides thiuram and tebuconazole are selected. The method of simultaneous determination of pesticides in grain offered. The recovery of pesticides was 90–95%. Lower bounds defined by the contents of pesticides, taking into account the concentration amounted to 0.005 mg kg−1 in the MEKC method, and 0.0025 mg kg−1 in the method of HPLC. The relative standard deviation of the results of the analysis is less than 0.09, analysis of the duration of 1–1.5 h.

ISE on Vitamin B6

Sensor obtained by ion associate of vitamin B6 with tetraphenylborate ion and determined its electrochemical characteristics. Method biionnyh potentials determined selectivity coefficients of the electrode. The method of determination of the main substance in the product «Pyridoxine hydrochloride».

Determination of thymol with micellar extraction preconcentration

For the efficient preconcentration of azo compounds – products of the interaction of 4-nitrophenyldiazonium with thymol, a system 4-nitroaniline (4-NA) – NO2 - – Triton X-100 – NaOH – ethanol has been proposed. The optimal conditions for the formation of micellarsaturated phases of the system under study have been established: 3. 10-4 M 4-NA – 3. 10-4 M NO2 - – 5% Triton X-100 – 2.8 M NaOH – 10 vol. % С2Н5ОН. A spectrophotometric study of the above system has been carried out.

Express determination of cephalexin

Test means based on immobilized Fehling’s reagent for the determination of cephalexin have been obtained. Methods for visual and colorimetric assessment of antibiotic concentration using a smartphone camera have been developed. The optimal conditions for the indicator reaction have been selected with varying heating time and temperature. For a visual semi-quantitative assessment of the content of cephalexin, a color scale has been obtained.

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