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Кратко рассмотрены методы получения и функционализации
поверхности магнитных наночастиц на основе магнетита, их
свойства и применение для разделения и концентрирования
неорганических и органических веществ.
 

Методом ДТА впервые изучен объединенный стабильный те-
траэдр LiF–RbI–Rb2CrO4–RbF, который входит в состав четы-
рехкомпонентной взаимной системы Li,Rb||F,I,CrO4
. Соединение
LiRbF2 плавится инконгруэнтно, а соединение Rb3FCrO4
 внутри
системы меняет характер своего плавления с конгруэнтного на
инконгруэнтный. Сконструированная в форме концентрацион-
ного тетраэдра трехмерная модель фазового комплекса систе-
мы позволила разграничить объемы первичной кристаллизации
фаз: LiF, RbF, RbI, Rb2CrO4
, LiRbF2
, Rb3FCrO4

It is shown that in the analysis of medicines fluoroquinolone by reversed-phase HPLC with fluorimetric detection modification mobile phase γ-cyclodextrin leads to a decrease in the detection limit of antibiotics to 8 times. The possibility of determination of cipro- floxacin in the presence of tetracycline and quinolone derivative series. The proposed method is tested in the analysis of pharmaceutical preparations containing ciprofloxacin.

A quantum chemical substantiation of the intermediate (thiyl radical) nature and reaction regioselectivity (S,S-coupling) of the L-cysteine homolytic oxidative dimerization resulting by the L-cystine formation has been carried out. The electrostatic factor does not prevent the reaction occurrence.

The influence of the nature of a modifying additive selected from the class of stabilizers and thickeners (high-molecular-weight chitosan, starch, xanthan gum, sorbitol, and pyridoxine hydrochloride) on the rheological properties of the concentrated chitosan–organic acid– water system (freshly prepared or stored at 4 and 20°C) was studied. It is shown that all the modifiers have a stabilizing and thickening effect, resulting in an increased viscosity of the multicomponent system and a lower rate of its fall in time.

The stable tetrahedron LiF-KF-KCl-K2WO4 of the quinary reciprocal system Li,K||F,Cl,WO4 was studied by differential thermal analysis, and the characteristics of eutectic and peritectic were determined.

The method of determination of tetracycline antibiotics (tetracycline, chlortetracycline, oxytetracycline, doxycycline) in the milk of methods HPLC-MS/MS/MS and HPLC-QTOF-MS, with a simple and rapid sample preparation. The ranges defined concentrations of tetracyclines in milk sample of 1 g was 1–200 μg/kg. Relative standard deviation of the results of the analysis does not exceed 7%. The analysis duration 30–40 minutes.

The phase diagram of the potassium thiocyanate–water binary system was studied by the visual polythermal method and by the method of time–temperature curves over а temperature range – 35–180 оС. There is an eutectic equilibrium at –32.6 оС in the system; the solid phases of this equilibrium are ice and individual potassium thiocyanate. The composition of the liquid phase of the eutectic state was determined.

Natural bentonite was modified with iron (III) and aluminum polyhy- droxocations by the sol–gel technique. This modification of natural bentonite has been found to cause changes in its chemical composi- tion, structural and sorption properties. The modified sorbents are fine-porous (nanostructured) objects with the predominance of 1.5–6.0 nm pore size. The specific surface area of our sorbents depends on the method of modification and the amount of the modifying component introduced (iron (III) or aluminum). The sorption capacity of the sorbents for permanganate anions was studied.