Entity

Time filter

Source Type


Prukaa D.,Adam Mickiewicz University | Prukaa W.,Adam Mickiewicz University | Szymalska M.,Masurian University in Olecko | Witkowska-Krajewska E.,Masurian University in Olecko | Kluska M.,Siedlce University Of Natural Sciences And Humanities
Journal of Liquid Chromatography and Related Technologies | Year: 2010

Benzyl derivatives of hydroxystilbazole show biological activity appearing as antimicrobial and anticancer effect. Moreover, these derivatives show properties of liquid crystals and can form complexes. In this paper are presented optimum conditions of separation and determination of two isomers, derivatives of hydroxystilbazole by a technique of isotachophoresis. (E)-N-(benzyl)-4'-hydroxystilbazole bromide and (E)-N-(benzyl)-2'- hydroxystilbazole bromides were subjected to an optimization process. Lengths of analysis steps, electric current intensity and pH of electrolyte solutions and samples were changed during the optimization of conditions. The shortest time of analysis was obtained during determination of individual isomers. However, in the case of mixtures, the time of analysis was lengthened two times and was at about 420 seconds. It was proven by a process of trial and error that optimum pH for analyzed isomers are 3.7. Source


Kluska M.,Siedlce University Of Natural Sciences And Humanities | Bombik E.,Siedlce University Of Natural Sciences And Humanities | Witkowska-Krajewska E.,Masurian University in Olecko | Erchak N.,Siedlce University Of Natural Sciences And Humanities
Journal of Liquid Chromatography and Related Technologies | Year: 2010

In this paper are presented optimal conditions of chromatographic separation of two isomers: γ-(chloropropyl)-3-furyldimethylsilane and [2-chloro(1-methyl)ethyl](3'-furyl)dimethylsilane. These isomers show the ability of modification of the surface of silica gel. In the investigation were tested three stationary phases and three mobile phases: dichloromethane, methanol, and a mixture of dichloromethane and hexane (80/20, v/v), in different flow intensities. An application of octadecyl stationary phase, which is recommended as a standard phase, did not yield separation of the isomers, independently of composition and flow of a mobile phase. Better results, but with asymmetric peaks have been obtained on the octyl phase. Finally, aryl chemically bonded phases permitted acquiring good separation of the isomers in a time shorter than 25min. The best separation factor (1.11) has been obtained on the chemically bonded aryl phase using dichloromethane with flow of 0.1mL min-1. Therefore, the best selectivity in separation of above mentioned compounds exhibited the aryl chemically bonded phase. Source


Kluska M.,Siedlce University Of Natural Sciences And Humanities | Witkowska-Krajewska E.,Masurian University in Olecko | Marciniuk-Kluska A.,Siedlce University Of Natural Sciences And Humanities
Oceanological and Hydrobiological Studies | Year: 2014

The paper presents the results of research on the content of 16 PAH, selected anions and heavy metals in samples collected from Lake Oleckie Wielkie. The samples were collected at seven locations around the lake within about 15 m from the shore in November 2012. The highest total concentration of 16 PAH (68.58 μmol dm-3) was found in water sample no. 7, and the lowest in water samples no. 1, 4 and 5. The obtained results do not exceed the levels of standards accepted in Poland for the surface water. The analysis of collected water samples, performed with the isotachophoresis method, showed a low content (less than 4 mg dm-3) of the analyzed anions: nitrates(V), nitrates(III), chlorides, sulphates(VI), sulphates(IV), phosphates(V) and hydrocarbonates(IV), as well as a low content of the analyzed heavy metals. © 2014 Versita Warsaw and Springer-Verlag Wien. Source

Discover hidden collaborations