The aim of the investigations was to use, for the first time, zirconia nanopowders stabilized with yttria (YSZ) and rare element oxides (YSZ-Nd, YSZ-Gd) for removal of humic acids (HA) from aqueous solutions. Nanopowders were synthesized by means of hydrothermal crystallization and characterized using scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) methods and analysis of zeta potential. The adsorption processes analysis was carried out in a series of experiments depending on: initial concentration of humic acids, contact time, pH and mass of the used adsorbent. It was found, that the YSZ-Nd exhibits strong and much higher effectiveness of HA adsorption than YSZ and YSZ-Gd. The HA adsorption rate reached 96.8% for YSZ-Nd dosage of 100 mg, pH 4, and 15 min reaction time and for HA initial concentration equal to 25 mg/L. According to the Langmuir model simulation, the maximum adsorption capacity of HA on YSZ-Nd at pH 4 was calculated to be 2.95 mg/g. Changes in the FT-IR spectra of YSZ-Nd confirmed humic acids' adsorption on the tested nanopowders, by the presence of additional bands representing carboxylic, alcohol, carbonyl and amino groups in humic acid structure. These functional groups could represent humic acids binding on the YSZ, YSZ-Nd or YSZ-Gd surfaces.

Our paper presents the possibility of phenol removal from post-processing wastewater originating from an experimental simulation of the underground coal gasification process carried out in the Barbara Experimental Mine in Mikolow, Poland. The application of initial coagulation-flocculation processes with iron(II), iron(III), aluminium, titanium(IV), and zirconium(IV) and anionic flocculant has allowed phenols removal from 7.9% (pH 8, Zr4+ 400 mg/L) to 22.2% (for pH 8, Fe2+ 800 and 1,000 mg/L and for pH 8, Fe3+ 1,000 mg/L). The application of the coagulation-flocculation process and advanced oxidation in the H2O2 /UV system resulted in a total reduction of phenolic concentrations in the treated wastewater by about 93% due to their reaction with OH center dot radicals, resulting from the UV rays impact on H2O2.

The aim of this study was evaluation of distribution microelements in human articular cartilage and to determine factors influencing it. The following elements were taken under consideration: Mg, Ca, Zn, Fe, Pb. Their concentration was assessed in the articular cartilage harvested from the loaded an unloaded area of human femoral heads. Initial results indicate that mechanical loadings are one of the important factors influencing distribution of microelements in human articular cartilage.

An adsorptive stripping voltammetric (AdSV) procedure for the determination of monobutyltin in aqueous media at a silver liquid amalgam film-modified silver solid amalgam annular band electrode (AgLAFAgSAE) is described. Determination of monobutyltin proceeds in two steps. At the beginning monobutyltin ions (BuSn3+) are accumulated from 0.1M NH4NO3 and 10% ethanol solution at a potential of -0.2V, than the BuSn0 film is preconcentrated at the working electrode surface at a potential of -0.7V. After this step the DP AdSV voltammogram is recorded. The analytical parameters and the procedure of the electrode regeneration and activation were optimized. The calibration curve of monobutyltin in the range 0.02-0.30mgL(-1) is linear (r=0.9973). The detection limit for 5s of preconcentration, calculated as 3 sigma of the blank was equal to 0.004mgL(-1), repeatability of the peak current was 1.8% (n=5). Repeatability and sensitivity of monobutyltin determination depends strongly on the analyzed solution properties, measurement conditions and the working electrode quality. The proposed procedure was tested by means of monobutyltin determination in tap waters.

The renewable mercury film-modified silver solid amalgam annular band electrode (MF-AgSAE) applied for quantitative determination of sub-nanomolar concentrations of Cr(VI) using differential pulse (DP) and normal pulse (NP) catalytic adsorptive striping voltammetry (CAdSV) is presented. In this context a signal processing algorithm is described and applied for the transformation of sigmoidal shaped NP curves to peak shaped curves. The method utilizes continuous wavelet transform (CWT) and a specially constructed mother wavelet defined using the ideal wave-shaped curve. It simplifies the interpretation of sigmoidal curves. In the effect the new strategy of Cr(VI) determination is 10 times more sensitive than differential pulse and square-wave techniques. The reproducibility is below 35?% (n=3) for the 0.22.2 nM concentration range of Cr(VI). The detection limit for 30 s preconcentration is equal to 0.05 nM with sensitivity of 0.809 +/- 0.012 mu A nM(-1) and is limited by the purity of the used reagents. The correlation coefficient is equal to 0.9993. For 2 nM of Cr(VI), in the tested range, 0 <= t(acc) <= 60 s, the relation wave height?accumulation time (I(w)t(acc)) is linear. The operation and effectiveness of the proposed procedures was confirmed by the quantitative determination of Cr(VI) in supporting electrolyte and CRM (surface water samples and urine) with known amounts of the analyte. The obtained results show substantial improvement of the performance of NP CAdSV technique.

The highly sensitive method of adsorptive stripping voltammetry (AdSV), with differential pulse steps, was performed at a mercury film electrode and has been applied here for the determination of trace molybdenum content in selected wild mushrooms. Fruiting body caps of 12 selected macrofungi species from Basidiomycetes have been investigated. Molybdenum content of investigated samples was determined in the range of 0.006 to 0.38 mg kg−1 of dry matter. The highest value of molybdenum content was found in Leccinum rufum and the lowest in Lactarius deliciosus.

Zanieczyszczenie rodowiska uranem nieznacznie, ale jednak w sposob systematyczny ci gle wzrasta. rod em zanieczyszczenia mog by zarowno procesy naturalne wywo ane erozj gleb i ska , a tak e antropogeniczne zwi zane z wydobyciem, przetwarzaniem i wzbogacaniem uranu dla potrzeb energetyki j drowej. Uran wyst puje praktycznie we wszystkich rodzajach ska , st d te mo e znajdowa si w materia ach ceramicznych, wytwarzanych na bazie surowcow naturalnych. Chemiczna toksyczno uranu podobna jest do o owiu, ponadto jest to pierwiastek radioaktywny. Bior c pod uwag negatywny wp yw radioaktywno ci uranu, konieczno oznaczania tego pierwiastka w ro nych surowcach i materia ach ceramicznych jest w pe ni uzasadniona. Wiele technik jest wykorzystywanych do oznaczania uranu w probkach naturalnych, jak np. spektrofotometria [1], -spektrometria [2], neutronowa analiza aktywacyjna [3], miareczkowanie kompleksometryczne [4], chromatografi a gazowa [5], spektrografi a emisyjna z plazmowym wzbudzeniem probki [6], polarografi a impulsowa [7]. Jednak e, cz sto metody te nie s wystarczaj co czu e do bezpo redniego Wykorzystanie adsorpcyjnej woltamperometrii stripingowej w ocenie zawarto ci uranu w surowcach i materia ach ceramicznych

A continuous wavelet transform with a specially defined dedicated mother wavelet is applied for data treatment as a signal-processing tool in a potentiometric titration. The inflection points of the titration curve are localized in one step of the calculations. The imperfection of signal, random noise, or spikes has no influence on the operation of the procedure. The proposed algorithm does not require any prior information about the nature or the type of analyte and/or the shape of the titration curve. Although the optimization of transformation parameters should be done, they may be chosen from a wide interval.The accuracy and precision of the proposed end-point estimation is examined on several simulated curves and instrumental potentiometric titrations. Under normal working conditions, analyte concentrations with variation coefficients between 1% and 5% have been determined. The procedure based on the wavelets provides an objective criterion for the determination of the end point. It can be reproduced and fully automated, thus contributing to a more versatile titration analysis.

New, renewable copper (Hg(Cu)FE) and silver (Hg(Ag)FE) based amalgam film electrodes applied for the determination of elemental sulfur using differential pulse cathodic stripping voltammetry are presented. With surface areas adjustable from 1 to 12 mm(2), both electrodes are characterized by very good surface reproducibility (<= 2%) and long-term stability (a few thousand measurement cycles). The mechanical refreshing of the amalgam film takes about 1-2 seconds. The effects of various factors such as instrumental parameters and the supporting electrolyte composition were optimized. Interferences from sulfides are easily removed by the addition of acid, and bubbling with argon, for Hg(Ag)FE. In the case of Hg(Cu)FE, sulfides did not interfere. The calibration graph is linear within the studied range from 16 ng L-1 to 4.8 mu g L-1 for Hg(Cu)FE, and up to 6.4 mu g L-1 for Hg(Ag)FE (t(acc)=15 s). The correlation coefficients for the two electrodes were at least 0.997. The detection limits for a low concentration of S(0) and t(acc)=60 s are as low as 14 ng L-1 for Hg(Cu)FE and 4 ng L-1 for Hg(Ag)FE. The proposed method was successfully applied and validated by studying the recovery of S(0) from spiked river water.

The TiC working electrode was tested as a novel, potential electrode for anodic stripping voltammetric determination of lead(II) ions traces. To demonstrate the practical applicability of the TiC electrode, all underpotential deposition/dissolution (UPD) phenomena system in electrolyte without removal of oxygen was tested. The electrode was constructed be means of mounting a TiC. disk (circle divide = 3.5 mm) in a resin body. Three compositions of TiC were tested differing in stoichiometry, namely TiC0.6, TiC0.8, and TiC1.0, The key problem is the method of electrochemical activation of the TiC electrode. No or improperly activated electrode is not polarized and is unsuitable as a voltammetric sensor. The TiC electrode was used for the determination of Ph2+ 2 in concentrations ranging from I to WOW. The instrumental parameters, composition of supporting electrolyte and procedures of the electrode activation were optimized. The repeatability of DP ASV runs in synthetic solutions covering the entire concentration range is better than 3%. The calibration curve is characterized by a correlation coefficient of at least 0.999. The detection limit was 2 nM for an electrodeposition time of 30 s. ne method enables determination of Pb2+ in the presence of, among the others. high excesses of Cd, Cu, In, Sb, Se, and Tl ions as well as surfactants, Triton X-100 and humic acids. The analvsis of Ph2+ in synthetic solutions with and without surfactants, certified reference material and natural water samples have been performed. The voltammetric data were associated with the structural characterization of the electrode surface using scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (XRF).

In the paper the new signal processing method which utilizes the continuous wavelet transform and especially defined a dedicated mother wavelet is proposed. In the definition knowledge of the ideal signal shape in the considered problem is used. The application of this algorithm in transformation of curves recorded by means of differential pulse voltammetry (DPV) and normal pulse voltammetry (NPV) is described. Transformation of the signals, elimination of noise, baseline correction and separation of overlapping data can be achieved in one step by means of the proposed procedure. Due to linearity of wavelet transform (WT) the whole process of quantitative determination of analyte may be realized in the wavelet coefficients space.

In the work the procedure of chromium(VI) determination by catalytic adsorptive stripping voltammetry (CAdSV) with application of fumed silica, is presented. Two variants of the method are proposed: in the first fumed silica is put directly to the electrolytic cell containing tested solution, in the second the silica is shaken with the sample and next centrifuged. The effectiveness of many surface-active substances removal from synthetic solutions as well as natural water samples, is studied. In the experiments the fumed silica (Sigma-Aldrich) of the specific surface area in the range 200-390 m(2) g(-1) was used. Two types of the working electrodes were applied, i.e., hanging mercury drop electrode (HMDE) and cyclic renewable mercury film electrode (Hg(Ag)FE). In the silica presence i) the relative standard deviation (RSD) for 0.1 mu g L-1 Cr(VI) is <2% (HMDE) and <5% (Hg(Ag)FE), n=7, ii) the detection limits estimated deposition time 20 s were respectively 14 ng L-1 (HMDE) and 22 ng L-1 (Hg(Ag)FE). The accuracy of the method was tested by studying the recovery of Cr(VI) from spiked natural water samples.

Chemometric analysis of the Dobczyce Reservoir sediments is presented herein. The sediments have been sampled at 17 points, dried, digested and quantitatively analyzed for 12 elements, covering a three-year period (2004-2006). Substantial variations in composition due to the hydrological and environmental reasons were found. The use of mathematical and statistical tools enables objective and effective analysis of obtained data.

The catalytic adsorptive stripping voltammetry (CAdSV) has been applied to physico-chemical chromium speciation study in the upper Dunajec catchment, severely polluted by the tannery wastewater. The method is based on the adsorptive preconcentration of the Cr(III)–diethylenetriammine-N,N,N′,N″,N″-pentaacetic acid (DTPA) complex and the utilization of the catalytic reaction in the presence of nitrate. Under optimized conditions the CAdSV enables the oxidation state speciation study of Cr content by direct determination of Cr(VI) in the presence of the predominant Cr(III) concentration with the detection limit for chromium(VI) of 0.08nM and the linearity range from 0.1 to 80nM obtained for 20s of accumulation, as well as the determination of total Cr after UV oxidation of Cr(III) to Cr(VI). Due to the difference in the chemical properties of different chromium species the CAdSV method makes possible a speciation study of Cr(III) and Cr(VI) oxidation state. The RSD of the determination of Cr(VI) and Cr(III) varies from 0.5 to 5%. It has been proved that in natural water in which strong complexants of Cr(III) such a humid acids are presented, Cr(VI) can be determined accurately in the presence of high excess of Cr(III). Fractionation of selected water samples with tangential flow filtration (TFF, cut-off 10 and/or 1kDa) provides insight into physical Cr speciation, i.e. partitioning of the Cr(VI) and Cr(III) between the colloidal and the dissolved fractions. It has been shown that the content of the Cr species in the Dunajec river depends on the season, and is significantly higher in autumn and winter during the most intensive tanneries production processes. The concentration of total Cr exceeds occasionally the legally admissible level. A large fraction of total Cr(III) concentration is associated with the colloidal material, while Cr(VI) occurs solely in the truly dissolved form.

In this paper we describe the stripping voltammetric method for the determination of metals in the presence of surfactants at the ppm level. The method employs fumed silica for selective adsorption of surfactants directly in the voltammetric cell. In the present work the suppressing effect of the surfactant is studied. The latter depends mainly on the kind of metal and on the parameters of the deposition stage. The fumed silica usually allows for the full restoration of the suppressed signal. In addition, it is possible to enhance the depolarizer signal in solution with silica suspension if high stirring rates are used during the deposition step. The method is validated by analyzing certified reference material and then tested with the natural sample.

Recent preclinical and clinical data indicate beneficial role of zinc in the antidepressant treatment. To evaluate the mechanism of interaction between zinc and antidepressants, in the present study we examined the brain zinc, imipramine and desipramine concentrations in mice treated with combinations of zinc and imipramine and subjected to the forced swim test. We have chosen doses of zinc (10 mg/kg) and imipramine (15 mg/kg) which we have previously found to be ineffective in the forced swim test when given alone. However, when administered jointly, a significant reduction in the immobility time in this test was demonstrated. In the present study, we demonstrated a significant ca. 60% reduction in the brain desipramine and non-significant reduction (ca. 40%) in brain imipramine concentrations in the group of animals treated with zinc plus imipramine compared with animals treated with imipramine alone. The brain zinc concentration in the zinc plus imipramine group was reduced when compared with the group treated with zinc or imipramine alone. Since there was no increase in brain imipramine/desipramine or zinc brain concentration after combined zinc and imipramine treatment, the data suggest that pharmacodynamic rather than pharmacokinetic interaction between zinc and imipramine is responsible for behavioral effect in the forced swim test.

Environmental fate of chromium rejected from tannery wastewater to the Dunajcc River (southern Poland) was investigated using separation with tangential flow filtration followed by measurements with Cathodic Adsorptive Stripping Voltammetry (CAdSV) and ICP-MS. Virtually all Cr(VI) was found in the dissolved fraction (< 1 kDa). This form was present at low concentrations. Cr(III) was rapidly transferred from dissolved and low molecular weight colloidal fractions to particles and high molecular weight colloids and thus scavenged from the water column of the Czorsztyn Reservoir to the sediments. The possibility of Cr remobilization via oxidation of Cr(III) in the presence of freshly precipitated Mn-oxides in water or at the water-sediment interface needs further investigation.