Factors Responsible for the Electrophoretic Behavior of Carboxylic Acid and Triazine Derivatives under Conditions of Capillary Zone Electrophoresis and Micellar Electrokinetic Chromatography

The effects of the pH, nature, and ionic strength of the running buffer; temperature; and surfactants, organic solvents, and macrocyclic compounds added to the buffer solution on the electrophoretic separation parameters of anionic, cationic, and neutral components of complex mixtures of organic compounds under the conditions of capillary zone electrophoresis and micellar electrokinetic chromatography. Pesticides from the series of chlorophenoxycarboxylic acids and triazines, as well as amino acids and substituted benzoic acid derivatives, were used as model systems. The predominant role of the addition of macrocyclic reagents, in particular, -cyclodextrin, as buffer electrolyte components was noted.     

Determination of aflatoxin M1 in milk using solid-phase extraction and high-performance liquid chromatography with fluorescence detection

Solid-phase extraction of aflatoxin Ml from milk using Diapak S16M and Diapak S solid-phase extraction cartridges followed by HPLC determination with a Flyuorat-02 fluorescence detector was studied.     

Reactions of 1,3-dibromopropyne with 1-aroyl-2,2-dimethylhydrazines as a new method for the synthesis of substituted 1,3,4-oxadiazinium bromides

Reactions of 1-aroyl-2,2-dimethylhydrazines with 1,3-dibromopropyne in MeOH or MeCN at 20—50 °C yield 2-aryl-6-bromomethylidene-4,4-dimethyl-5H-1,3,4-oxadiazinium bromides.     

Family of instantons of the Kraichnan model with a frozen velocity field

We find the family of instantons of the Kraichnan model with a frozen velocity field. Using these instantons, we investigate the asymptotic behavior of higher orders of the perturbation theory series constructed for the response function. We demonstrate that although the number of diagrams increases factorially with the degree of the perturbation series term, the perturbation series itself has a finite and sometimes even infinite convergence radius. We thus disprove the commonly accepted view that the type of series convergence can be determined by estimating the number of diagrams in higher orders of the perturbation theory. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 158, No. 2, pp. 200–213, February, 2009.     

Synthesis and structure of silyl-substituted imidazol-2-ylidenes and their precursors

Previously unknown heterocyclic carbenes and their precursors containing a silicon atom in the side chain were prepared. Their structures were studied by multinuclear ¹H, ¹³C, ¹⁵N, and ²⁹Si NMR spectroscopy.     

Sorption and Separation of Optical Isomers of 2-Butanol by Chiral Porous Coordination Polymers

Theoretical and Experimental Chemistry - It was shown that porous coordination polymers (PCPs) of 3d metals containing chiral centers in fragments of deprotonated (S)-lactic and (R)-aspartic acid...