Heavy metals as indirect causative factors of capillaropathy

By applying systemic analysis to a set of random variables, representing blood or urine concentrations of certain enzymes, lipids and metals, three direct causative factors of capillaropathy, in its early stage, i.e. leucine amino peptidase, free erythrocyte protoporphyrin and C(3)-complement, have been found. The interactions between the early stage of capillaropathy and these factors have been quantitatively described and a formula for prognosing the capillaropathy occurrence has been proposed. It has also been shown that the following heavy metals Pb, Cd, Cr, Cu, Mg, Fe and Ca, through their direct or indirect interactions with C(3)-complement, exert an influence on the occurrence and intensity of capillaropathy. Since direct causative factors of a given pathology can serve as its markers, the completeness of the set of the capillaropathy markers, formed from the causative factors, and their contributions to this pathology have been evaluated. The results were obtained by examining a population of male residents chronically exposed to heavy metals (Pb, Cu) in the environment.     

Heavy metals as toxicants in big cities

Heavy Metals (HMs) can exert detrimental effects on human health and on the environment. Their ecotoxicological properties are generally well known. As regards human toxicology, new aspects should be taken into consideration—gender and age dependence. The HMs chemical risk can be estimated and in this context, city demography data help to evaluate today's ecological situation (including HMs) and to predict the dynamics of future urbanization.As regards urban atmosphere, motor vehicles (Pb) and industry (V, Ni, Cr, Cd) exert the greatest influence; water, soil, vegetation also experience menace caused by HMs. Urban environments should be protected against contamination posed by HMs: the health status of big cities is dependent on adequate and safe supply of water. Vegetation plays a helpful role in reducing HM content in the atmosphere and the soil. Awareness of the inhabitants regarding the risks posed by HMs also counts as critical factor today. Ecoeducation at the beginning of the new century can be taken into consideration.     

Heavy metals as stressing factors in the red wood ants (Formica polyctena) from industrially polluted forests

Relations between metal contaminations in social groups of ants from colonies of Formica polyctena, from 5 localities variously contaminated by industrial pollution, and their metabolic and detoxifying strategies have been investigated. Cd, Pb, Zn, Mn, Cu levels have been measured in social groups of workers and pupae throughout the season. Patterns of metabolic, transport and detoxifying enzymes have been assayed and phosphoadenine nucleotides and the energy charge (AEC) have been determined. The metal content is a measure of the level of contamination and has been the highest in foragers returning to the nest. Body burdens of Cd, Pb and Zn diminished progressively from the surface workers to those from the inner part of the hill. The concentration of total adenylates was slightly lower than stated in Finnish ants poisoned with Cd, but the AEC index was always above 0.8, with high variations between the social groups. Carboxylesterases showed a positive correlation of activity pattern with the metal load in foraging workers, with the highest value for cadmium load in ants from a locality in the middle of a pollution gradient. The pattern of superoxide dismutase activity has been site-dependent, but it did not correlate well with the metal load in workers.     

Heavy metals as stressing factors in the red wood ants (Formica polyctena) from industrially polluted forests

Relations between metal contaminations in social groups of ants from colonies of Formica polyctena, from 5 localities variously contaminated by industrial pollution, and their metabolic and detoxifying strategies have been investigated. Cd, Pb, Zn, Mn, Cu levels have been measured in social groups of workers and pupae throughout the season. Patterns of metabolic, transport and detoxifying enzymes have been assayed and phosphoadenine nucleotides and the energy charge (AEC) have been determined. The metal content is a measure of the level of contamination and has been the highest in foragers returning to the nest. Body burdens of Cd, Pb and Zn diminished progressively from the surface workers to those from the inner part of the hill. The concentration of total adenylates was slightly lower than stated in Finnish ants poisoned with Cd, but the AEC index was always above 0.8, with high variations between the social groups. Carboxylesterases showed a positive correlation of activity pattern with the metal load in foraging workers, with the highest value for cadmium load in ants from a locality in the middle of a pollution gradient. The pattern of superoxide dismutase activity has been site-dependent, but it did not correlate well with the metal load in workers.     

Heavy metals in human urinary calculi

Summary Heavy metals are incorporated in human urinary calculi during a complex pathological process. The trace metals cadmium, lead, chromium, nickel and mercury are determined with regard to significance in pathogenesis and therapy. The amounts of cadmium, lead and chromium were determined as well directly in the solid sample as after chemical digestion by Zeeman-GFAAS. Both analyzing techniques show corresponding results. Nickel could be determined after chemical digestion only, while mercury was determined by a solid sampling technique. The evaluation of the results of trace metal analysis in the pilot study of 11 urinary calculi showed increased amounts of lead and cadmium compared to the results of tartar and salivary calculi.     

Heavy metals in petroleum-contaminated surface soils in Serbia

Investigation of heavy metal contamination levels as well as their association types with substrates in petroleum-contaminated surface soil was carried out using modified sequential extraction method. In that way, remobilization capacity of metal cations, both in natural conditions and in accidents, has been studied. Moreover, partitioning of heavy metals, originating from spilt oil derivative, among surface soil substrates was estimated. Extreme contamination with lead was discovered, as well as the increased concentrations of zinc and copper. Oil-derived Pb and Zn were found to be distributed between carbonates and amorphous Fe-oxides, whereas Cu was found to be dominantly associated with amorphous Fe-oxides. Appreciable amounts of these metals were also found to be incorporated into more resistant structures. In petroleum-contaminated surface soil, substrates of cadmium are carbonates, whereas nickel has the great affinity toward hydrous Mn-oxides. Cd is proven to be the most mobile metal in oil-contaminated surface soil.     

Capillary zone electrophoresis of rare earth metals with indirect UV absorbance detection

The separation of 14 lanthanides by capillary zone electrophoresis was studied in the background electrolyte containing hydroxyisobutyric acid as complexing counter-ion and creatinine as a UV absorbing coion for indirect detection of lanthanide zones. A complete separation was achieved in less than 5 min and the applicability of the method for the analysis of real samples was demonstrated.     

Heavy metals in river sediments — A chemometrical evaluation

First results are presented to support decisions within projects of recultivation in the Merseburg region. From two places of the river Luppe eight sediment samples were taken at four different days. The total concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined by ICP-AES after digestion with aqua regia both in the gross samples and in four particle size fractions obtained by wet sieving. Subsequently each fraction was split into six classes by a sequential extraction to characterise the pattern of heavy metal binding form. Questions about the difference of the regions, the importance of the particle size fractions, the mobility of the metals, and the influence of the seasonal factor were tried to answer by the help of chemometrical methods. It was possible to show that the two sampling places situated only about 7 km from each other have different total metal concentrations as well as different binding form patterns. The trend of the heavy metal enrichment in the smallest particle size fraction can easily be seen in two-dimensional diagrams, but could in general not be confirmed statistically for all metals. The consideration of all four factors together (region, particle size fraction, mobilisation class, and time) shows the significant influence caused by all factors and all interactions. Multivariate covariance analysis is used to include also the influence of sampling conditions.Dedicated on the occasion of his 70th birthday to Professor Dr. Klaus Doerffel, who has spent much of his life in teaching and introducing statistical and other chemometrical techniques in Analytical Chemistry     

Heavy metals and adsorbents effects on activated sludge microorganisms

The sorption of Cu(II) and Cd(II) from synthetic solution by powdered activated carbon (PAC), biomass, rice husk (RH) and activated rice husk (ARH) were investigate under batch conditions. After activated by concentrated nitric acid for 15 hours at 60-65 degrees C, the adsorption capacity for RH was increased. The adsorbents arranged in the increasing order of adsorption capacities to the Langmuir Q degree parameter were biomass > PAC > ARH > RH. The addition of adsorbents in base mix solution had increased the specific oxygen uptake rate (SOUR) activated sludge microorganisms with and without the presence of metals. The increased of SOUR were due to the ability of PAC and RH in reducing the inhibitory effect of metals on microorganisms and provide a reaction site between activated sludge microorganisms and substrates.     

Heavy metals adsorption by novel EDTA-modified chitosan-silica hybrid materials

Ionic liquid based microemulsions were characterized by absorption solvatochromic shifts, (1)H NMR and kinetic measurements in order to investigate the properties of the ionic liquid within the restricted geometry provided by microemulsions and the interactions of the ionic liquid with the interface. Experimental results show a significant difference between the interfaces of normal water and the new ionic liquid microemulsions. Absorption solvatochromic shift experiments and kinetic studies on the aminolysis of 4-nitrophenyl laurate by n-decylamine show that the polarity at the interface of the ionic liquid in oil microemulsions (IL/O) is higher than at the interface of water in oil microemulsions (W/O) despite the fact that the polarity of [bmim][BF(4)(-)] is lower than the polarity of water. (1)H NMR experiments showed that an increase in the ionic liquid content of the microemulsion led to an increase in the interaction between [bmim][BF(4)(-)] and TX-100. The reason for the higher polarity of the microemulsions with the ionic liquid can be explained in terms of the incorporation of higher levels of the ionic liquid at the interface of the microemulsions, as compared to water in the traditional systems.     

Chiral metals as electrodes

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Estimation of metals as sulphides : Estimation of platinum metals

1. It has been shown that all the platinum metals with the exception of osmium can be estimated as sulphide if the solution containing the metal is treated with a large excess of alkali sulphide followed by excess of acetic acid and ammonium acetate. The precipitate of the sulphide can be washed with water, alcohol and ether successively, dried in a vacuum desiccator, and weighed. 2. By the above procedure it is possible to complete the analysis for all the platinum metals within 3 hours, whereas the procedures described in the literature require much longer time —in many cases more than 24 hours. 3. The precipitates obtained by the older procedures were very sticky and difficult to filter. By carrying out the precipitation in the presence of acetic acid and ammonium acetate it has been possible to obtain the precipitate in an easily filterable form. 4. The above method not only provides a very convenient general method of estimating the platinum metals, but also throws interesting light on the formation of thiosalts and the precipitation of sulphides by their decomposition.     

Heavy metals in selected soils of the semi-arid region of Nigeria

Eight soil profiles developed on crystalline basement complex rocks in the semi-arid region of Nigeria were analyzed for total contents of cesium (Cs), chromium (Cr), cobalt (Co), hafnium (Hf), iron (Fe), lanthanum (La), lutetium (Lu), scandium (Sc), thorium (Th), uranium (U) and ytterbium (Yb). The contents range from 50.3–95.4 Cs, 16.1–58.1 Cr, 0.6–9.0 Co, 9.0–34.8 g g^–1 Hf, 0.31–3.69% Fe, 17.2–60.7 La, 60.4–90.6 Lu, 2.6–12.6 Sc, 8.3–21.5 Th, 4.7–9.2 U and 3.6–92 g g^–1, Yb. Their corresponding means were 68.4, 35.1, 4.0, 19.9 g g^–1, 1.70%, 37.1, 79.4, 6.5, 14.7, 6.7 and 5.0 g g^–1. In general, total Cs, Co, Fe, La, U and Yb increased with further increase with depth. On the other hand, Lu, Sc and Th showed no distinct vertical distribution within the profiles. All eleven elements were correlated with the amounts of clay present in the soils, the correlation being stronger for Cs, Th, Yb, Cr and Lu.     

Heavy metals and color retention by a synthesized inorganic membrane

In this study, a new type of a double-layer ceramic membrane was used for the filtration of wastewater. The synthesized membrane consists of a macroporous substrate (with pore size of about 0.1 μm) prepared following the colloid filtration technique and a thin film functional layer (with pore size of about 10 nm) carried out according to the sol–gel preparation method.The ceramic membranes were tested for the removal of cadmium, zinc, Methylene Blue and Malachite Green from water under a pressure of 5 bar and a treatment time of 2 h. Liquid filtration and flow tests through these membranes resulted in a rejection rate of 100% for Methylene Blue and Malachite Green. This paper also presents the ability of the tubular membrane prepared to separate heavy metals (cadmium and zinc) from their synthetic aqueous solutions. The influence of the applied pressure, feed solute concentration, feed pH on the rejection of cadmium and zinc ions was studied. Retention rates of cadmium and zinc ions of 100% were observed for an initial feed concentration of 10⁻⁴ mol/L.     

Phenylalanine as eluent for indirect photometric detection

Summary In this paper the use of phenylalanine as eluent for indirect photometric chromatography is reported. The effects of the mobile phase pH, phenylalanine concentration etc. on the eluent strength and the sensitivity of detection are discussed. Using 3 mM aqueous solution of phenylalanine at pH 3.0 containing 1% methanol as the mobile phase, a mixture of alkali metals was separated and sodium ion concentration in water was determined on a low-capacity cation-exchange column.     

Electrochemical factors controlling the patterning of metals on SAM-coated substrates

Alkanethiol self-assembled monolayers (SAMs) have been used in electrochemical microfabrication processes. The reductive desorption potential of alkanethiol SAMs, Edes, can be comparable to, greater than, or less than the metal reduction potential during electrodeposition, Emet. As a result, the SAM layer can passivate the surface or desorb simultaneously with metal deposition. We show that these electrochemical traits can be combined with a rastering microjet electrode to pattern SAMs directly and create patterned metal films without lithography steps. For the case of copper deposition on 1-octanethiol (OT)- and 1-dodecanethiol (DT)-coated substrates, Edes is significantly negative of Emet, resulting in high-resolution metal patterns with poor nucleation and poor adhesion to the substrate. However, nickel patterns deposited on 1-butanethiol (BT), OT, and DT have traits similar to bare gold (excellent nucleation and adhesion) because Edes is positive of Emet. Substrates with SAMs also suppress adventitious chemistries that occur distant from the rastering microjet electrode, such as oxygen reduction, making samples more corrosion resistant and improving the overall patterning process that we call electrochemical printing.     

Heavy metals assessment in the hair of street children by INAA method,Isfahan

The street children phenomenon is an increasing problem in most cities of the world including Isfahan, which is a fast growing town. The number of street children with the growth of the town is increased. It is therefore important to have baseline data on their health problems. Hair element analysis remains an important tool in the nutritional and environmental assessment of them. A measurement of the elemental concentration in recently-grown hair provides an integrated view of the element status in the follicular cells and their blood supply, unaffected by short term fluctuations in the nutrient intake of the subject. This study aimed to assess heavy metals concentrations in the hair of street children in Isfahan using neutron activation analysis method. The concentration of heavy metals (Cu, Cr, Fe, Hg, Mn, and Zn) of 17 Iranian street children (Isfahan) was examined. Data analysis found that different profiles of the concentrations of Cr, Hg, Mn, and Zn were seen in each sample. These results were discussed with reference to show of environmental effects.