Wyniki wyszukiwania - Biblioteka Nauki

1

Analytical methods for the detection of Osminum Tetroxide: A review

100%

Svorc L. , Tomcik P. , Durdiak J. , Rievaj M. , Bustin D.

Polish Journal of Environmental Studies

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2012

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tom 21

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nr 1

EN

A strong oxidizer, osmium tetroxide (OsO4) is a highly toxic and irritative species. Its volatility enhances the risk of intoxication by inhalation in areas with poor ventilation. Osmium tetroxide attacks mainly skin, mucous membranes, nose, and eyes at very low concentrations. These are the main reasons why osmium tetroxide may be abused as a chemical weapon in public areas with limited air circulation (airports, shopping centres). Therefore, stringent monitoring is needed. Analytical methodologies, approaches, and strategies for the detection of osmium tetroxide are comprehensively surveyed in the proposed work.

2

Trace determination of lead in environmental and biological samples by anodic stripping voltammetry on carbon paste electrode

100%

Rievaj M. , Tomcik P. , Cernanska M. , Janosikova Z. , Bustin D.

Chemia Analityczna

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2008

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tom Vol. 53, No. 5

717-723

EN

A simple and sensitive electroanalytical method - a differential pulse anodic Stripping Yoltammetry with unmodified carbon pastę electrode - was used for trace analysis of lead in environmental and biological samples. Carbon was used as the working electrode material due to its good accessibility, low cost, excellent sensitivity, and environmental non-toxicity. The linear dependence of DPASV signal on Pb(II) concentration in the analyzed solution was observed in the range from 2 x 10-8 to l x 10-7 mol L-1 with detection limit of 5 x l0-9 mol L-1 Pb(II). The method enabled trace determination of lead in tap and enyiron-mental waters at the concentration level approved by state regulations, and also in human urine samples at the concentration level comparative to that provided by spectral methods, hoveyer at much lower costs.

PL

Użyto prostej i czułej metody elektroanalitycznej do oznaczania śladów ołowiu w próbkach środowiskowych i biologicznych. W metodzie zastosowano anodową, stripingową, różnicową woltamperometrię (DPASY) i elektrodę z niemodyfikowanej pasty grafitowej. Materiał węglowy wybrano ze względu na łatwą dostępność, niski koszt, wysoką czułość i niską toksyczność środowiskową. Zależność liniową sygnału DPASY od stężenia Pb( II) otrzymano w zakresie od 2 x 10-8 do l x l 0-7. Granica wykrywalności wynosiła 5 x l 09 mol L-1. Metoda umożliwia oznaczanie ołowiu w wodzie wodociągowej i środowiskowej na poziomie stężenia dopuszczalnego przez normy państwowe. Metoda pozwala również oznaczać ołów w moczu ludzkim na poziomie stężeń porównywalnych z metodami spektralnymi przy dużo niższych kosztach.

3

Determination of trace Mn(II) in pharmaceutical diet supplements by cathodic stripping volammetry on bare carbon paste electrode

100%

Rievaj M. , Tomcik P. , Janosikova Z. , Bustin D. , Compton R. G.

Chemia Analityczna

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2008

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tom Vol. 53, No. 1

153-161

EN

A simple electroanalytical method for quantification of Mn in pharmaceutical diet supplements has been developed. The method is based on the formation of insoluble MnO, on the electrode during deposition step at the potential of+0.85V vs SCE. and its consecutive reductive dissolution back to Mn(II) during differential puJse voltammetry scan. Pure carbon paste was found to be a suitable material for this kind of determination because of its easy preparation, good accessibility, low cost, as well as its appropriate analytical properties. In 0. l mol L-1 phosphate buffer (pH 7.4) supporting electrolyte and at optimised deposition time (120 s) the linear calibration plot was obtained in the concentration range 1 x 10-6-12 x 10-6 mol L-1; the corresponding detection limit was 1 * 10-7 mol L-1, The method was applied to the analysis of pharmaceutical dosage forms containing manganese as an essential trace element.

PL

Opracowano prostą, elektroanalityczną metodę oznaczania Mn w uzupełniających dietę preparatach farmaceutycznych. Metoda jest oparta na powstawaniu nierozpuszczalnego MnO, na powierzchni elektrody w czasie zatężającej elektrolizy przy potencjale +0,85 V vs NEK. Utworzony osad rozpuszczał się w trakcie rejestrowania pulsowegowoltamperogramu różniczkowego na skutek redukcji do Mn2+. Użytecznym materiałem elektrodowym do tego typu oznaczeń, okazaJa się czysta pasta węglowa -jest tania, iatwa do preparowania i ma odpowiednie właściwości analityczne. W roztworach buforu fosforanowego (O, l mol L-1 pH 7.4) pray optymalnym czasie zatężania (120 s) liniowe krzywe kalibrowania uzyskanow zakresie stężeń 1 x 10-6-12 x 10-6 mol L-1. Granica wykrywalności wynosiła l x 10-7 mol L-1. Metodę zastosowano do analizy preparatów farmaceutyznych, w których mangan był istotnym pierwiastkiem śladowym.

4

Boron-doped diamond electrode as sensitive and selective green electroanalytical tool for heavy metals environmental monitoring: zinc detection in rubber industry waste

72%

Culkova E. , Svorc L. , Tomcik P. , Durdiak J. , Rievaj M. , Bustin D. , Brescher R. , Lokaj J.

Polish Journal of Environmental Studies

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2013

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tom 22

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nr 5

EN

A simple and sensitive electroanalytical technique for the detection and quantification of zinc has been developed that demonstrates beneficial analytical features of boron-doped diamond electrode. The influence of deposition potential on the stripping peak current of zinc was studied, and optimum value of -1.7 V vs. Ag/AgCl electrode was chosen. Optical and atomic force microscopic studies showed that the mechanism of deposition process is governed by nucleation by which first nanoparticles and then grains of zinc are formed. The detection limit of 4.7×10⁻¹⁰ mol·l⁻¹, good repeatability (relative standard deviation of 3.2%) as well as wide linear dynamic range from 5×10⁻¹⁰ to 5×10⁻⁶ mol·l⁻¹ were obtained in 0.1 mol·l⁻¹ KCl for deposition time of 120 s. Interference from other heavy metals such as Hg²⁺, Cu²⁺, Pb²⁺, and Cd²⁺ do not significantly influence anodic stripping peak of zinc even in a 100-fold excess. The method was applied in analysis of zinc in environmental rubber industry samples with results in good agreement with those obtained by atomic absorption spectrometry, confirming that the boron-doped diamond electrode is an excellent sensing tool for heavy metals environmental monitoring.