Bioelectrodes based on pseudocapacitive cellulose/polypyrrole composite improve performance of biofuel cell.

Enzymatic electrodes with high internal capacitance, based on cellulose/polypyrrole composite were optimized and utilized to design improved enzymatic fuel cell. Fructose dehydrogenase Gluconobacter sp. specifically adsorbed on the cellulose/polypyrrole matrix and electrophoretically immobilized and electrochemically entrapped Laccase Trametes versicolor, were used as the anode and cathode bioelectrocatalysts, respectively.

Nanoparticles: their potential toxicity, waste and environmental management.

This literature review discusses specific issues related to handling of waste containing nanomaterials. The aims are (1) to highlight problems related to uncontrolled release of nanoparticles to the environment through waste disposal, and (2) to introduce the topics of nanowaste and nanotoxicology to the waste management community. Many nanoparticles used by industry contain heavy metals, thus toxicity and bioaccumulation of heavy metals contained in nanoparticles may become important environmental issues.

Fractionation study in bioleached metallurgy wastes using six-step sequential extraction.

The stored metallurgy wastes contain residues from ore processing operations that are characterized by relatively high concentrations of heavy metals. The bioleaching process makes use of bacteria to recover elements from industrial wastes and to decrease potential risk of environmental contamination. Wastes were treated by solutions containing bacteria.

Speciation analysis of arsenic in terrestrial plants from arsenic contaminated area.

Arsenic speciation analysis was carried out in plants collected from arsenic contaminated area. Two plant species were chosen for the investigation: Reed Grass (Calamagrostis arundinacea) and Lady Fern (Athyrium filix-femina). To characterize arsenic species several different extraction procedures were applied including enzymatic extraction and extraction using surfactant solution (SDS).

Iterative absolute electroanalytical approach to characterization of bulk redox conducting systems.

A novel electroanalytical approach is proposed here, and it is demonstrated with the direct and simultaneous determination of two unknowns: the concentration of redox sites and the apparent diffusion coefficient for charge propagation in a single crystal of dodecatungstophosphoric acid. This Keggin-type polyoxometalate serves as a model bulk redox conducting inorganic material for solid-state voltammetry. The system has been investigated using an ultramicrodisk working electrode in the absence of external liquid supporting electrolyte.

Electroanalytical methods for determination of the metal content and acetic-acid-available metal fractions in soils.

The pseudo-total and available arsenic, cadmium, and lead content of soils have been determined by stripping voltammetry with a hanging-mercury-drop electrode and by atomic absorption spectrometry with electrothermal atomization. For determination of pseudo-total metals microwave digestion with a mixture of HNO3 and HClO4, with and without addition of HF, was investigated. The single-extraction procedure with 0.

Selective leaching of elements associated with Mn-Fe oxides in forest soil, and comparison of two sequential extraction methods.

For selective dissolution of Mn oxides as components of soil (easily reducible oxides) 0.05 mol L(-1) and 0.1 mol L(-1) NH2OH.

Analytical control of silica glass production. Voltammetric determination of titanium and iron in raw materials and silica glass samples.

Adsorptive stripping voltammetric (AdSV) methods are presented for the determination of titanium and iron in quartz and silica glass samples obtained after pressure decomposition. Mandelic acid and catechol were used as complexing agents for titanium and iron, respectively. The method for titanium determination is based on the catalytic effect of chlorate ions.

Granulometry and the content of toxic and potentially toxic elements in vacuum-cleaner collected, indoor dusts of the city of Warsaw.

Twenty-seven sites, together with 23 household dust sample sites, representing the home environment, and four public room dust sample sites, representing working environment (mainly offices) have been described in this paper. The latter were examined to obtain an approximate reference to the home environment data. All the samples were collected between May and July 1997 by a vacuum-cleaner method, in the city of Warsaw, Poland.

Standard species from Poland for environmental specimen bank.

The Environmental Specimen Bank has proposed a list of matrices recommended for collection from terrestrial and marine areas as well as from inland waterbodies. There have been taken into consideration the most common and available species, chiefly in western Europe. Poland is making ready for co-operation with ESB to gather samples within the country and must consider a number of regional differences resulting from among others geographical distinction (another quantity of populations, spatial distribution etc.

Voltammetric method for the determination of Zn, Cd, Pb, Cu and Ni in interstitial water.

To determine heavy metals in interstitial water from Baltic sea sediments a sampling method with subsequent voltammetric determination is described. Copper, lead, zinc and cadmium are determined in the UV-digested samples of interstitial water by differential pulse anodic stripping voltammetry while nickel is determined by adsorption voltammetry. The determination of five metals in one sample in a wide concentrations range is possible using a low cost apparatus.

Determination of cobalt in vegetable animal foodstuffs by differential pulse adsorptive voltammetry using alpha-benzil dioxime.

A selective and sensitive voltammetric method for the determination of cobalt in vegetable animal foodstuffs is developed. The method is based on the use of alpha-benzil dioxime (alpha-BD) as a chelating agent for differential pulse adsorptive stripping voltammetry (DPASV) and is free from zinc interferences. The influence of pH, time and alpha-BD concentration on the peak resolution and height are discussed.

Determination of cobalt in blood using cathodic stripping voltammetry.

A method was developed to determine low levels of cobalt in whole blood, serum and plasma. Samples of blood (0.2 ml) were mineralized at 160 degrees C in the presence of concentrated nitric acid.

Feathers of the magpie (Pica pica) as a bioindicator material for heavy metal pollution assessment.

This study examined the lead and cadmium content of external tail feathers of magpies from 15 localities in Poland, differing in degree of industralization and urbanization. Extremely high levels (up to 1500 micrograms/g dry wt. Pb and about 40 micrograms/g dry wt.

Trends in heavy metal levels in the dissolved and particulate phase in the Dutch Rhine-Meuse (Maas) Delta.

Levels of the heavy metals Cd, Cr, Cu, Pb and Zn, in both the dissolved and particulate phase, were determined in two sampling campaigns in August 1978 and August 1984 in the Dutch Rhine-Meuse (Maas) Delta. Besides the heavy metal concentrations, other important parameters were determined, such as the concentrations of seston, chlorophyll and nutrients. The concentrations of dissolved Cd and of Cd, Pb and Cu in particulate matter were much higher in 1978 than in 1984, especially for Cd.

Determination of mercury in freeze-dried muscle samples of pike, cod and perch using an ASV-technique.

Determination of mercury in fish muscle samples can be made by an anodic stripping voltammetric technique (ASV) using a gold disc as the working electrode. Prior to analysis deep-frozen fish were thawed and then dissected using quartz scalpels. The freeze-dried samples were homogenised by the brittle fracture technique.

A rapid high-performance analytical procedure with simultaneous voltammetric determination of toxic trace metals in urine.

For the monitoring of toxic trace metals in urine a new high-performance trace analytical procedure with simultaneous voltammetric determination is presented. Particular emphasis has been placed on minimizing contamination by reducing the urine sample volume to 1 ml and consequently limiting the needed amount of HNO(3)/HClO(4) and the duration (<20 min) of the wet digestion stage. The procedure consists of three stages.

Toxic trace metals in food. II. A comparative study of the levels of toxic trace metals in wine by differential pulse anodic stripping voltammetry and electrothermal atomic absorption spectrometry.

A new high-performance analytical procedure for the determination of the toxic trace metals cadmium, lead and copper in wines by differential pulse anodic-stripping voltammetry (DPASV) subsequent to UV irradiation of the sample is compared with the hitherto more common application of electrothermal atomic absorption spectrometry (AAS). In this manner also mutually the accuracy attainable with both alternatives has been established. The particularly favourable potentialities of the new voltammetric approach for toxic metal control of wines are demonstrated by the investigation of a typical selection of 36 wines from recent vintages and common vine types of the German and some European wine cultivating regions.

Toxic trace metals in food. I. A new voltammetric procedure for toxic trace metal control of wines.

A new highly sensitive and particularly reliable analytical procedure for the precise determination of the most relevant toxic trace metals cadmium, lead and copper in wine is presented. It consists of a simple and convenient sample pretreatment by UV irradiation (1,5 h, 500-W-Hg-lamp) to release the toxic trace metals bound by organic substances and subsequent voltammetry (DPASV) of cadmium and lead simultaneously at a mercury film electrode (MFE) formed in situ on a vitreous carbon carrier and of copper on a gold electrode. Particular emphasis has been placed on the efficient exclusion of interference due to contamination.