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Dive into the research topics where Jerzy Siepak is active.

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Featured researches published by Jerzy Siepak.


Talanta | 2010

New method for speciation analysis of aluminium fluoride complexes by HPLC-FAAS hyphenated technique.

Marcin Frankowski; Anetta Zioła-Frankowska; Jerzy Siepak

Speciation analysis of aluminium in the presented system of HPLC-FAAS hyphenated technique lasts 4min. Using the bifunctional column in model analysis and using the calculation methods for modelling using the Mineql program enabled the authors to presume that particular forms will be subjected to elution in the following order: (1) AlF(2)(+) and AlF(4)(-), (2) AlF(2+) and AlF(3)(0) and (3) Al(3+). Based on the obtained results for model solutions, the presented method enables the determination of aluminium fluoride complexes and Al(3+) speciation form. The study compares the tendency of occurrence variability of aluminium fluoride complexes and Al(3+) form, determined based on the results obtained using the HPLC-FAAS hyphenated technique with the trend defined based on the Mineql program calculation method. The method was successfully applied to soil samples.


Science of The Total Environment | 1999

Research on the variability of physico-chemical parameters characterising acid precipitation at the Jeziory Ecological Station in the Wielkopolski National Park (Poland).

Barbara Walna; Jerzy Siepak

Here the water quality of precipitation at the Adam Mickiewicz University Ecological station is presented for the period 1992-1997 to examine one of the main factors causing the degradation of the natural environment of the Weilkopolski National Park. In the course of daily observations the amount of rainfall, its electrical conductivity and pH were measured. As much as 61% of the tested precipitation had a pH < 4.6, and 92% had a pH < 5.6; some very low pH values, even below 3.0, were occasionally observed. The annual volume-weighted average pH during the full period was 4.28 and the lowest yearly average was 3.92 (1994). The chemical composition of precipitation showed the dominance of sulphate and calcium ions. Fluoride ions also contributed significantly to the anion charge. There were also small amounts of heavy metals and polycyclic aromatic hydrocarbons. A chemical analysis of throughfall showed a considerably increased concentration of some ions, in particular potassium.


Talanta | 2009

Development of a new analytical method for online simultaneous qualitative determination of aluminium (free aluminium ion, aluminium-fluoride complexes) by HPLC-FAAS.

Anetta Zioła-Frankowska; Marcin Frankowski; Jerzy Siepak

The paper presents a novel method for simultaneous online examination of inorganic forms of aluminium: AlF(2)(+), AlF(2+,) and Al(3+) by means of the high performance liquid chromatography hyphenated with a detection by the atomic absorption spectrometry with flame atomization (HPLC-FAAS) without post-column reaction. The application of optimization procedure conditions of chromatographic separation of inorganic forms of aluminium was achieved by the analytical column IonPac CS5A (Dionex) with guard column IonPac CG5A (Dionex) and an aqueous ammonium chloride mobile phase, at pH about 3 with gradient elution. The separation of Al forms with nominal charge of 1+, 2+, 3+ required a run time of less than 8 min during a single analysis. The proposed method has been successfully used for the examination of aluminium forms formation AlF(n)((3-n)+) in environmental samples.


Microchemical Journal | 2002

Comparison of modifiers for determination of arsenic, antimony and selenium by atomic absorption spectrometry with atomization in graphite tube or hydride generation and in-situ preconcentration in graphite tube

Przemysław Niedzielski; Marcin Siepak; Jerzy Siepak

The study was performed to compare the effect of magnesium modifier (magnesium nitrate) with that of other modifiers (palladium nitrate and nickel nitrate) in determination of arsenic, antimony and selenium by atomic absorption spectroscopy with atomization in a graphite tube, with generation of hydrides and in situ preconcentration in a graphite tube. The assumed criterion of a modifier performance was the magnitude of the analytical signal. It was found that in determinations with atomization in a graphite furnace the effects of all these modifiers were comparable, while in those with hydride generation and in situ preconcentration in a graphite tube the magnesium modifier showed poorer performance (25% decrease of the analytical signal). In determinations of arsenic and selenium the analytical signal obtained with magnesium salt as a modifier was comparable with those obtained in the presence of all other modifiers.


Science of The Total Environment | 1998

The impact of acid rain on calcium and magnesium status in typical soils of the Wielkopolski National Park

Barbara Walna; Stanisław Drzymała; Jerzy Siepak

Abstract The previous investigation of the chemical characteristics of precipitation within the Wielkopolski National Park has shown its high acidity which sometimes drops below pH 3.0. This paper deals with calcium and magnesium ion leaching by acid rain from typical soils of the area. Laboratory experiments were conducted on soil monoliths (15 cm in diameter, 50 cm high) with acid solutions of pH 3.0, pH 2.0 and a water control of pH 5.6. The sprinkling lasted 30 days, simulating a rainfall of 400 mm. The eluates were analysed every day. The soil properties and forms of calcium and magnesium were determined before and after treatment. The investigations show that quite large amounts of Ca 2+ and Mg 2+ can be leached from soil — in the very acid treatment (pH 2.0) leaching amounted to about 100 mg Ca 2+ and 17 mg Mg 2+ per kg of soil. The leaching of these elements was several times less in the pH 3.0 and 5.6 treatments. The differences in the dynamics of the process is shown on the leaching curves — their shapes are smooth when pH is 5.6 and 3.0, while a sharp peak is present at pH 2.0.


Central European Journal of Chemistry | 2006

Chemometrics in the assessment of the sustainable development rule implementation

Aleksander Astel; Grażyna Głosińska; Tadeusz Sobczyński; Leonard Boszke; Vasil Simeonov; Jerzy Siepak

The sustainable development rule implementation is tested by the application of chemometrics in the field of environmental pollution. A data set consisting of Cd, Pb, Cr, Zn, Cu, Mn, Ni, and Fe content in bottom sediment samples collected in the Odra River (Germany/Poland) is treated using cluster analysis (CA), principal component analysis (PCA), and source apportionment techniques. Cluster analysis clearly shows that pollution on the German bank is higher than on the Polish bank. Two latent factors extracted by PCA explain over 88 % of the total variance of the system, allowing identification of the dominant “semi-natural” and “anthropogenic” pollution sources in the river ecosystem. The complexity of the system is proved by MLR analysis of the absolute principal component scores (APCS). The apportioning clearly shows that Cd, Pb, Cr, Zn and Cu participate in an “anthropogenic” source profile, whereas Fe and Mn are “semi-natural”. Multiple regression analysis indicates that for particular elements not described by the model, the amounts vary from 4.2 % (Mn) to 13.1 % (Cr). The element Ni participates to some extent to each source and, in this way, is neither pure “semi-natural” nor pure “anthropogenic”. Apportioning indicates that the whole heavy metal pollution in the investigated river reach is 12510.45 mg·kg−1. The contribution of pollutants originating from “anthropogenic sources” is 9.04 % and from “semi-natural” sources is 86.53 %.


Water Air and Soil Pollution | 2000

The Impact of Acid Rain on Potassium and Sodium Status in Typical Soils of the Wielkopolski National Park (Poland)

Barbara Walna; Stanisław Drzymała; Jerzy Siepak

A previous investigation of thechemical characteristics of precipitation in theWielkopolski National Park has shown its high acidity,which sometimes drops below pH 3.0. This paper dealswith the leaching of potassium and sodium ions by acidrain from typical soils of the study area. Laboratoryexperiments were conducted on undisturbed soil cores(15 cm in diameter, 50 cm high) with acid solutions of pH 3.0, pH 2.0 and with water of pH 5.6 (control). The sprinkling lasted 30 days simulating a rainfall of 400 mm. The eluates were analysed daily. Soil propertiesand forms of potassium and sodium were determinedbefore and after treatment. The investigations showthat quite significant amounts of K+ andNa+ can be leached from the soil: in the very acidtreatment (pH 2.0) about 4 mg K+ and 3 mgNa+ per kg of soil. The leaching of these elementswas smaller in the pH 3.0 and 5.6 treatments.Differences in the dynamics of the process are shownin the leaching curves. In the case of potassium theirshapes are smooth when pH is 5.6 and 3.0, while at pH2.0 the curves rise sharply. The leaching curves inthe case of sodium do not show sharp peaks, whichmeans that the leaching is slow and equalised.


Analytica Chimica Acta | 1989

Use of a terbium chelate as label in spectrofluorimetric determinations of protein traces

Jerzy Siepak

Abstract A spectrofluorimetric method for the determination of protein traces using the terbium complex formed with diethylenetriaminepentamethanephosphonic acid and p -aminosalicyclic acid as reagents is described. The method has been applied to the trace determination of simple proteins at concentrations down to 10 −11 M in the pH range 2.5–11.


Oceanological and Hydrobiological Studies | 2009

Water ecosystems affected by human impact within the protected area of the Tatra National Park (Poland).

Iwona Kurzyca; Adam Choiński; Alfred Kaniecki; Jerzy Siepak

Water ecosystems affected by human impact within the protected area of the Tatra National Park (Poland) The subjects of the study were two high-mountain lakes, Morskie Oko and Czarny Staw pod Rysami, in the Tatra range of the Carpathian Mountains located within the protected area of the Tatra National Park. This paper presents results of the analytical study of the lake water composition and compares this with relevant data from earlier years. The impact of the following factors was distinguished and discussed: atmospheric deposition (dry and wet), migration of pollutants with runoff water supplying both reservoirs, tourism (hiking, climbing), and the influence of mountain hostels. The resistance and sensitivity of the lakes to human impact is described in terms of water quality changes and characteristics of the catchments and the region.


Soil and Sediment Contamination: An International Journal | 2012

Variability of Mercury Concentrations in Soil and Leaves of Acer plantanoides and Tilia platyphyllos in Poznań City, Poland

Artur Kowalski; Marcin Frankowski; Anetta Zioła-Frankowska; Agnieszka Mocek-Płóciniak; Jerzy Siepak

The paper presents the results of research on mercury in the soil and leaves of maple (Acer plantanoides) and linden (Tilia platyphyllos) collected in the four districts of the city of Poznań (Poland), which differ in terms of anthropogenic pressure. The average concentration of mercury in soil was 132 μg kg−1. The highest concentration of mercury was determined in Tilia platyphyllos (233 μg kg−1), whereas in Acer plantanoides it amounted to 207 μg kg−1. Based on the study, it was found that the highest concentration of mercury in the investigated leaf species was observed in the samples collected in the districts of Grunwald, Jeżyce, and Old Town. The lowest concentration was observed in the samples collected in the district of New Town. The comparison of the obtained results of mercury concentration in soil and leaf samples was made in terms of anthropogenic pressure in the investigated areas and depending on the studied leaf species. Based on the statistical analysis, it was found that there is no statistically significant relationship between mercury concentration in both studied species of trees. There was, however, a relationship between the mercury concentration in leaves and soil.

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Marcin Frankowski

Adam Mickiewicz University in Poznań

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Marcin Siepak

Adam Mickiewicz University in Poznań

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Barbara Walna

Adam Mickiewicz University in Poznań

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Przemysław Niedzielski

Adam Mickiewicz University in Poznań

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Anetta Zioła-Frankowska

Adam Mickiewicz University in Poznań

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Artur Kowalski

Adam Mickiewicz University in Poznań

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Iwona Kurzyca

Adam Mickiewicz University in Poznań

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Patrycja Siudek

Adam Mickiewicz University in Poznań

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Leonard Boszke

Adam Mickiewicz University in Poznań

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