концентрирование

Determination of thymol with micellar extraction preconcentration

Authors: Tsygulyova E. I., Doronin S. Y.

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.

Pre-Concentration and Extraction of Samarium Isotopes by Precipitation of Slightly Soluble Hydroxides and Fluorides of Metals

Authors: Salmenbayev S. E., Nurgaysinova N. K., Umarov M. A.

The comparison and assessment of the efficiency of using the precipitation of sparingly soluble metal hydroxides and fluorides for the extraction and pre-concentration of samarium isotopes from the solution simulating acidic leachate of the soil were made. It was shown that the precipitation of samarium isotopes was achieved quantitatively at the pH of about 7 and the co-precipitation of alkaline and alkaline earth elements did not exceed 20%.

Preconcentration of Е110 and Е124 Food Azodyes on Magnetite Nanoparticles Modified by CTAB

Authors: Kazimirova K. O., Khabibullin V. R., Reshetnikova I. S., Egunova O. R., Shtykov S. N.

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. One of the most popular and effective is magnetic solid-phase extraction (MSPE) with the use of magnetic nanoparticles (MNP).

ЭКСТРАКЦИОННОЕ «CLOUD POINT» КОНЦЕНТРИРОВАНИЕ СОЕДИНЕНИЙ СВИНЦА МИЦЕЛЛЯРНЫМИ ФАЗАМИ ПАВ

Authors: Мозан А. А., Данчук А. И., Doronin S. Y., Chernova R. K.

Рассмотрен аналитический метод – «экстракция в точке помут-

нения» применительно к концентрированию и выделению соеди-

нений свинца из различных матриц. Дана характеристика при-

меняемых для этих целей ПАВ. Оценены факторы, влияющие

на коэффициент, константу распределения и коэффициент кон-

центрирования хелатов в мицеллярные фазы ПАВ. Дана срав-

нительная характеристика лигандов-комплексообразоват елей,

применяемых для мицеллярной концентрации ионов свинца.