Trace Metal and Persistent Organochlorine Levels in Wood Bison (Bison bison athabascae) from the Mackenzie Bison Sanctuary

Abstract

Tissue samples were collected from ten healthy mature female wood bison (B. bison athabascae) for examination. Livers and kidneys were tested for toxic heavy metals and trace metals considered as essential nutrients for successful reproduction, while fat samples were analyzed for persistent chlorinated hydrocarbons. No elevated levels of toxic heavy metals (arsenic, cadmium, lead, mercury) were found and essential trace elements (copper, manganese, selenium, zinc) were within the acceptable ranges established for healthy cattle. All fat samples tested contained trace levels of α-BHC (mean value, 23 ppb) and lindane (mean value, 3 ppb).     

Thermal Conductivity of Selenium Doped with Indium and Iodine in the Solid and Liquid States

Abstract

We have measured the thermal conductivity in both solid and liquid states for two amorphous samples. The first is selenium doped with indium and the second is selenium doped with iodine. The concentration of In and I in the samples were 50000 ppm. Measurements were taken in a temperature range from 1000 to 370°C, and were carried out using the concentric cylinder method, which is based on the flow of heat through a cylindrical wall.     

Determination of Selenium (IV) in Biological Sample by Cathodic Stripping Voltammetry

Abstract

The determination of selenium (IV) in biological sample using cathodic stripping voltammetry is reported. It was found possible to determine selenium directly in biological samples containing such metals as zinc (II), lead (II), iron (III), arsenic (III) and magnesium (II). The results for selenium in bovine liver are reported.     

Enhancement of Sensitivity for Selenium Determination in Atomic Absorption Spectrophotometry by Introducting Hydrogen Selenide into an Argon-Hydrogen Flame

Abstract

The sensitivity for selenium determination with atomic absorption spectrophotometry is enhanced to a large extent by introducing hydrogen selenide gas into an argon-hydrogen flame. As a reducing agent, zinc granular and stannous chloride is successfully used for quantitative and rapid productions of hydrogen selenide from selenium(IV) solution. The sensitivity for 1 % absorption of the signal is estimated to be about 0.02 ppm of selenium.     

Determination of Traces of Copper,Lead, and Cadmium in Cobalt by Derivative Pulse Polarography

Abstract

A derivative pulse polarographic method is described for determining traces of copper, lead and cadmium in cobalt and its compounds without separation. In hydrochloric acid medium the detection limits are respectively about 0.02, 0.04 and 0.1 ppm in metallic cobalt when analysing 2 M cobalt solutions. The procedure was applied to the analyses of synthetic and commercially available cobalt samples and showed a satisfactory sensitivity and precision at various concentrations levels of the three impurities.     

Ultraviolet Spectrophotometric Determination of Selenium by 1-Pyrrolidinecarbodithioate Method

Abstract

An ultraviolet spectrophotometric method for the determination of selenium has been developed using ammonium 1-pyrrolidinecarbo-dithioate. The selenium(IV)-1-pyrrolidinecarbodithioate complex is extracted with chloroform and the absorbance of the extract measured at 303 mμ. Conformity to Beer's law was found for 0.5 to 9 ppm of selenium.     

Simultaneous Gas Chromatographic Determination of Nitrobenzene and 2,4-Dinitrophenol in Nitrobenzene Manufacturing Plant Wastewater

Abstract

A simple and rapid gas chromatographic procedure is described for the identification and quantification of pollutants in the nitrobenzene manufacturing plant wastewater. The samples were extracted with methylene chloride and subsequently nitrobenzene and 2,4-dinitrophenol were analysed by GC using FID. The method was found to be precise and accurate and applicable for monitoring the effluent treatment system at ppm levels.     

TISSUE SELENIUM LEVELS AND GROWTH RESPONSES OF MICE FED SELENOMETHIONINE,SE-METHYLSELENOCYSTEINE OR SODIUM SELENITE

Abstract

Mice fed diets containing selenomethionine at a level of 20 ppm selenium and raised to 30 ppm selenium at 3 weeks on experiment showed (1) delayed response to selenium toxicity, (2) slow recovery from the toxicity after removal of selenium from the diet and (3) relatively high deposition and retention of tissue selenium. These data suggest that selenomethonine initially becomes incorporated in to the primary structure of proteins and as such is not particularly toxic. However, upon its slow removal from protein, selenomethionine becomes toxic by forming selenium IV compounds through a pathway similar to that followed by methionine.

Mice fed diets containing sodium selenite or Se-methylselenocysteine at the same level of selenium as the selenomethionine diet showed (1) immediate response to selenium toxicity (2) rapid recovery from the toxicity after removal of selenium from the diet and (3) relatively low deposition and relatively rapid depletion of tissue selenium. These data suggest that sodium selenite and Se-methylselenocysteine ultimately follow similar metabolic pathways and do not become part of the primary structure of proteins. A possible metabolic route for Se-methylselenocysteine is that it is oxidized to toxic selenium IV compounds through an oxidative pathway similar to that followed by S-methylcysteine.     

Simultaneous Determination of Heavy Metals in Bovine Liver and Oyster Tissue by Solvent Extraction-Reversed Phase High Performance Liquid Chromatography

Abstract

High performance liquid chromatographie method for the simultaneous determination of ppm levels of cadmium, nickel, lead, zinc, cobalt, copper and bismuth in biological samples has been developed. Each 250 mg of Bovine Liver(NBS 1577) or Oyster Tissue(NBS 1566) was ashed in a muffle furnace over night at 500 to 55O°C. Then the ash was treated with 1.5 ml of 2 N hydrochloric acid; and the solution was put into a separatory funnel. The dissolved heavy metals were extracted into chloroform as hexamethylenedithiocarbamato chelates. The metal chelates were separated on a reversed phase column(5 μm, ODS, 4.6 × 15O mm), and determined by measuring the peak height of each metal chelate. Cd, Ni, Pb, Zn and Cu were determined accurately over the concentration range of 0.5–850 ppm with standard deviation ca. 7%.     

Atomic Absorption Spectrometry Analysis of Silicates by the Absorption Tube Technique

Abstract

By the combined use of the absorption tube technique and solvent extraction, determination of cadmium, cobalt, copper, iron, lead and nickel in silicate rocks was investigated.

Applicable concentration range was from 0.1 to 1.Oppm for all the elements except cadmium, for which the range was from 0.005 to 0.025ppm. The accuracy and recovery determined by the use of standard samples from the United States National Bureau of Standards and Geological Survey were satisfactory for practical purposes.     

Residues Analysis of Post-Harvest Imidazole Fungicides in Citrus Fruit by H PLC and GLC

Abstract

The determination of imazalil and prochloraz fungicide residues has been carried out by HPLC with an UV detector at 204 nm and by GLC with an electron capture detector (ECD).

In both cases fungicide residues were extracted with hexane/acetone (90:10, v/v) after pH adjustment and purified by a liquid-liquid partitioning process. When HPLC was used for prochloraz and imazalil analysis, it was necessary to eliminate the interfering substances with a further clean-up process. This was also required when samples with low residue levels were analyzed by GLC.

Recovery was always higher than 70%. The detection limit was 0.04 ppm for the HPLC method and 0.02 for the GLC method.

Imazalil and prochloraz residues in “Washington Navel” oranges and “Hernandina” clementine fruits, dipped in a 1000 ppm fungicide solution, are reported.     

Lead in Hair of Children Exposed to Gross Environmental Pollution

Abstract

In the context of a cross-sectional study, concentrations of lead in hair (PbH) were determined by atomic absorption analysis among 263 children aged 1 to 9 years, living less than 900m from a lead smelter in Santo Amaro City, Bahia, Brazil. PbH levels ranged from 20 to 4933 ppm; the median was 349 and the geometric mean was 313 ppm. The mean PbH level was increased among individuals with the following characteristics: female; younger age; shorter distance between residence and smelter; longer residence time in the area; racial group Dark; curly hair; being a child of a lead worker; high lead content in peridomiciliar area. The mean PbH level did not vary markedly according to the child's nutritional status, iron status and the habit of pica. The marked variations in pbH levels point out the feasibility of its use as an epidemiological index in situations of heavy environment pollution.     

Determination of trace metals by voltamperometry in zebra mussel (Dreissena polymorpha) employed as environmental bio-indicator

Abstract

In the present work, metals (cadmium, lead, copper, nickel, tin, selenium, and mercury) have been estimated in the Ebro River (Spain) using the zebra mussel (Dreissena polymorpha) as an environmental bio-indicator. In two sequential studies, in 2006 and 2008, concentrations of metals were calculated in water as well as in the shells and fleshes of the zebra mussels. Samples were collected from assorted locations of the river. Metals were determined successfully at trace levels through voltamperometry, a sensitive technique. It has been noted that analysis of bioaccumulators like zebra mussels can be helpful in evaluating metal pollution in water.     

Determination of Selenium in Natural Waters Using the Centrifugal Photometric Analyzer

Abstract

A rapid ion exchange separation converts the methylene blue spot test for selenium into a selective and sensitive method for quantitative determination of trace quantities of selenium. Increased speed, accuracy, and reproducibility is achieved because of the parallel analysis technique of the centrifugal photometric analyzer (GeMSAEC Fast Analyzer). Natural water samples, spiked with 0.10 to 0.5 μg of selenium, were analyzed with an average accuracy of 4.2 % after removal of interferences by ion exchange.     

Determination of Biphenyl in Citrus Fruits by Quantitative Thin-Layer Chromatography

Abstract

Residues of the fungicide biphenyl in citrus fruits have been determined by direct scanning of spots on phosphor-impregnated high performance silica gel TLC plates under UV light. Biphenyl was separated from fruit tissue by steam liquid-liquid extraction. Recoveries from spiked samples ranged from 92–99% at 100, 50, and 10 ppm levels. The precision of the TLC determination and overall procedure are shown to be adequate for residue analysis.     

The Determination of Trace Amounts of Tellurium and Selenium in Gallium Metal

Abstract

Analytical methods have been developed for the separation, concentration and determination of trace quantities of tellurium and selenium from primary and scrap gallium metal. A chloroform extraction is made of the tellurium diethyldithiocarbamate complex at a pH of 8.5. This extraction, in the presence of ammonium citrate, allows the satisfactory determination of tellurium by emission or atomic absorption spectrohcopy. The limit of sensitivity of the method is 0.5 pg of tellurium in 1.0 gram of gallium (0.5 ppm Te).     

Bestimmung kleiner Sauerstoffgehalte in Selen

Zusammenfassung Es wird eine Analysenmethode zur Bestimmung von Sauerstoff in Selen beschrieben. Die Abtrennung des Sauerstoffs geschieht über seine Umsetzung mit Schwefel; die Endanzeige des gebildeten Schwefeldioxids erfolgt colorimetrisch mit Parafuchsinchlorid. Mit dem Verfahren werden Gehalte bis 0,5 ppm (w)¹ erfaßt. Die relative Standardabweichung bei Analysen von SeO₂- und TeO₂-dotiertem Selen beträgt ±8%. Die Analysen von 5 Selenproben als Perlen ergaben Gehalte zwischen 4 und 11 ppm (w) Sauerstoff; Selengleichrichterschichten enthielten 1 ppm (w) Sauerstoff.

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Determination of small oxygen contents in selenium

An analysis method for the determination of oxygen in selenium is described. The separation of oxygen is accomplished through its reaction with sulphur. The final measurement of the sulphur dioxide formed is made colorimetrically with parafuchsine chloride. With this method contents as low as 0.5 ppm (w) can be determined. The relative standard deviation for analyses of selenium doped with SeO₂ and TeO₂ is ±8%. The analyses of 5 selenium samples having the form of beads resulted in oxygen contents between 4 and 11 ppm (w), whilst selenium rectifier layers contained 1 ppm (w) of oxygen.

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Die Verfasser bedanken sieh für das fördernde Interesse von Herrn Prof. Dr. W. Gebauhr und Herrn Dr. A. Spang. Zur Arbeit trugen wesentlich die anregenden Diskussionen mit Herrn J. Martin bei.     

Determination of Fluorine in Vegetation by Proton Activation Analysis

Abstract

Techniques have been developed for proton activation analysis using the ¹⁹F(p,p′y)¹⁹F reaction to measure the fluorine content of pulverized samples of vegetation which have been exposed to fluorides in the atmosphere or soil. The method is non-destructive and neither the chemical form of fluorine in the sample nor the type of vegetation analyzed appears to affect results. Calibration is performed by analyzing samples to which known amounts of fluorine are added. The fluorine content of 11 vegetation samples was determined by proton activation analysis and by standard chemical techniques. The values obtained by the two methods were in generally good agreement. Fluorine concentrations greater than 1 ppm can be measured with uncertainties ranging from about 50% at 5 ppm to less than 10% at concentrations above 50 ppm.     

Cadmium,Copper, Lead,Manganese, and Selenium Levels,and Glutathione Peroxidase Activity in Human Kidney Cortex

Abstract

Cadmium, copper, lead, manganese, and selenium concentrations and glutathione peroxidase (EC 1.11.1.19) activity have been determined in human kidney cortex specimens obtained at autopsy. Trace metal concentrations for each specimen were determined in the same digest, while glutathione peroxidase activity was assayed in tissue collected at a site adjacent to that selected for the trace metal determinations. Glutathione peroxidase activities were determined with two substrates, hydrogen peroxide and t-butylhydroperoxide. The effects of age, smoking history, sex, race, and blood pressure on kidney cortex trace metal levels and glutathione peroxidase activity were investigated. Mean kidney cortex cadmium concentration was found to be significantly higher in smokers than in nonsmokers (p=0.010). In addition, the mean kidney cortex lead concentration of hypertensive individuals was found to be significantly higher than that of non-hypertensive individuals (p=0.017), Glutathione peroxidase activities utilizing hydrogen peroxide substrate were inversely correlated to kidney cortex manganese levels (p=0.004).     

Pervaporation as a Separation Technique for Direct Determination of Volatile Selenium Species by Atomic Fluorescence Spectrometry

Abstract

This paper reports for the first time a suitable way to determine methylated selenium compounds using the new approach of pervaporation coupled to atomic fluorescence spectrcmetry (PV-AFS).

The method developed allows direct extraction, separation, preconcentration and determination of dimethylselenium (DMSe) and dimethyldiselenium (DMDSe) from slurry samples. Under the optimum conditions, the detection limits (LODs) were found to be 0.66 ng and 0.39 ng for DMSe and DMDSe, respectively, the precision being about 6–9 % for 10 ng mL as selenium concentration. The linearity ranges were from the LOD to 0.7 μg mL^?1 for DMSe and from the LOD to 0.4 μg mL^?1 for DMDSe (as Se). The pervaporation efficiencies were 55 ± 1 % and 85 ± 5 % for DMSe and DMDSe, respectively. The proposed method was successfully applied to determine methylated selenium species in sewage sludge, garlic and oyster samples. The concentrations found were from 0.07 to 1.42 μg g^?1.

As no certified reference materials are available for these analytes, validation was carried out by recovery studies in these matrices, and the results showed that the proposed method performed satisfactorily.