A Protocol for Minimizing Contamination in the Analysis of Trace Metals in Great Lakes Waters

Nriagu, Jerome O.; Lawson, Greg; Wong, Henry K.; Azcue, José M.

doi:10.1016/s0380-1330(93)71207-1

Cited by 124 publications

(72 citation statements)

References 26 publications

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“…The Teflon cloud water collector, HDLPE (high density linear polyethylene) sample bottles, LPE transport bags, chemical storage bottles, rinse-water containers and wash-bottles were pre-cleaned and presealed under class-100 conditions. The cleaning, storage and transport protocol is given by Nriagu et al [1993].…”

Section: Total Mercury In Cloud Watermentioning

confidence: 99%

Vertical distribution of gaseous elemental mercury in Canada

Banic¹,

Beauchamp²,

Tordon³

et al. 2003

J. Geophys. Res.

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[1] Measurements of gaseous elemental mercury (GEM) were made in three locations in Canada at altitudes from 0.1 to 7 km. In the summer in southeastern Canada, northwesterly winds bring air with a constant mixing ratio of GEM at altitudes up to 7 km, with a concentration near 1.5 nanograms per standard cubic meter of air (ng sm À3 ). In the winter in southern and central Ontario the mixing ratio is still approximately constant with altitude, but the concentration is 1.7 ng sm À3 . In the spring in the Arctic the concentration of gaseous elemental mercury at altitudes above 1 km is near 1.7 ng sm À3 ; however, there is evidence of episodic depletion of elemental mercury near the surface with mixing of depleted air to altitudes of 1 km. Measurements of GEM in cloud interstitial air and of mercury in cloud water indicate that the influence of a single cycling of air through cloud has little effect on the concentration of GEM. The GEM in air masses transported over the relatively unpopulated terrain of northern Canada during the summer indicates a lower limit of 5000 ng m À2 for an atmospheric column from the surface to 5 km. This gives a global burden of at least 2500 t for that altitude range. These data demonstrate the existence of a vast pool of mercury aloft, provide evidence for a long atmospheric lifetime, and illustrate the potential for long-range atmospheric transport of this metal at altitudes up to at least 7 km.

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Section: Total Mercury In Cloud Watermentioning

confidence: 99%

Vertical distribution of gaseous elemental mercury in Canada

Banic¹,

Beauchamp²,

Tordon³

et al. 2003

J. Geophys. Res.

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“…Nriagu et al, 1993). The washed equipment must be dried in a clean room or a laminar flow hood to avoid contamination resulting from the deposition of ambient dust, which is known to contain trace metals such as Cd and Pb (e.g., Feng and Barratt, 1994).…”

Section: Precipitation and Sorptive Loss Of Metal From Solutionmentioning

confidence: 99%

“…The washed equipment must be dried in a clean room or a laminar flow hood to avoid contamination resulting from the deposition of ambient dust, which is known to contain trace metals such as Cd and Pb (e.g., Feng and Barratt, 1994). For a compilation of the trace metal concentrations present in common laboratory materials (e.g., filters, paper tissues, powdered gloves), see Hume (1973) and Nriagu et al (1993).…”

Section: Precipitation and Sorptive Loss Of Metal From Solutionmentioning

confidence: 99%

Coupling the use of computer chemical speciation models and culture techniques in laboratory investigations of trace metal toxicity

Twiss

Errécalde²,

Fortin

et al. 2001

Chemical Speciation & Bioavailability

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Chemical Speciation and Bioavailability (2001), 13(1) ABSTRACTThe bioavailability and toxicity of a dissolved metal are closely linked to the metal's chemical speciation in solution. A variety of inorganic and organic ligands are often used in laboratory toxicity tests to control the concentration of labile trace metal in solution. Computerised chemical speciation models based on thermodynamic principles can be used to estimate metal speciation under such experimental conditions. However, these models are sensitive to the quality of their thermodynamic databases. Detailed protocols for the incorporation of reliable equilibrium formation constants into widely available computer chemical speciation programs (e.g., MINEQL+ and MINTEQ) are provided. The examples demonstrate both the benefits and the potential pitfalls involved in the use of chemical speciation models. The application of chemical speciation modelling to metal toxicity studies is discussed and guidelines are proposed for its proper use. Both defined media and chemical speciation programs have co-existed for two decades but the combined use of these techniques has been reserved for those possessing in-depth knowledge of both chemistry and biology. The techniques presented should enable an investigator with basic biological, chemical and computing skills to design an aqueous medium and incorporate correct thermodynamic constants into a computer chemical speciation program, starting from a standardised database, thereby providing a sound framework for critically assessing the biological response of a particular test organism to a given metal.

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“…The sample was placed in the shaker for 24 h, then centrifuged for 20 min, filtered with a 0.4 mm Millipore polycarbonate filter and 20 mL of the supernatant was preserved with 0.5 mL of 0.02 M EDTA for analysis. Polycarbonate filters have shown negligible interference with dissolved organic carbon (DOC) or speciation of metals (Khan and SubramaniaPillai 2007;Nriagu et al 1993). The tube and moist soil were weighed again.…”

Section: Adsorptionmentioning

confidence: 99%

Measurement and modeling of surface charge and cation binding in agricultural soil

Taillon

Hendershot²

2008

Can. J. Soil. Sci.

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Taillon, K. M. and Hendershot, W. H. 2008. Measurement and modeling of surface charge and cation binding in agricultural soil. Can. J. Soil Sci. 88: 749Á759. Models of metal adsorption have typically been developed and tested for soil components rather than whole soils and at cation concentrations higher than usual environmental conditions. This study investigates whether the non-ideal consistent competitive adsorption (NICA) model can be applied to ion binding in whole soils at low total metal concentrations. Surface charge was measured for 18 agricultural soils from southern Quebec over the pH range 3.5 to 8. The adsorption of Ca, Cd, Cu, Pb and Zn was also measured for three total metal concentrations of 2, 5 and 10 mg L(1 at pH 6 in a 0.005 M Ca(ClO 4 ) 2 solution. NICA model parameters were solved for each soil using the surface charge and adsorption data and a non-linear least squares fitting routine. Two types of binding sites were identified: the first type had a pK a near 4 while the second type had a pK a near 7.5. The first type of binding site contributed the greater proportion of the variable charge over most of the pH range, and the second site was unimportant at the lower pHs. The surface charge was accurately described by the NICA model with a mean R 2 of 0.995. A mean of the surface charge parameters describing H ' binding accounted for more than 95% of the variable charge on the soils. For individual soils, the NICA model gave a fit to the experimental data with mean R 2 values for Ca, Cd, Cu, Pb and Zn of 1.00, 0.906, 0.879 (two concentrations only), 0.825 and 0.918 respectively. When mean adsorption parameters, instead of values determined for each soil individually, are used, the model gave mean R 2 s for Ca, Cd, Cu, Pb and Zn of 0.938, 0.941, 0.998 (two concentrations only), 0.978 and 0.935. It seems that the NICA model can be used to describe the surface charge and adsorption of cations by whole soils. The mean adsorption parameters appear to describe the adsorption behavior of the soil nearly as well as the individually fitted parameters. This implies that mean parameters for these agricultural soils may provide satisfactory predictions for the adsorption behavior of similar soils. En ge´ne´ral, les mode`les d'adsorption des me´taux ont e´te´cre´e´s et teste´s pour les composantes du sol plutoˆt que pour le sol complet, et a`une concentration de cations supe´rieure a`celle habituellement observe´e dans l'environnement. La pre´sente e´tude devait e´tablir si on peut appliquer le mode`le d'adsorption stable concurrentielle en conditions non ide´ales (NICA) a`la liaison des ions dans le sol entier, quand la concentration totale de me´taux est faible. Pour cela, les auteurs ont mesure´la charge superficielle de 18 sols agricoles du sud du Que´bec dont le pH variait de 3,5 a`8. Ils ont aussi mesure´l'adsorption du Ca, du Cd, du Cu, du Pb et du Zn a`trois concentrations totales de me´taux [2, 5 et 10 mg par litre a`pH 6 dans une solution a`0,005M de Ca(ClO 4 ) 2 ]. Ils ont de´termine´les parame...

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A Protocol for Minimizing Contamination in the Analysis of Trace Metals in Great Lakes Waters

Cited by 124 publications

References 26 publications

Vertical distribution of gaseous elemental mercury in Canada

Vertical distribution of gaseous elemental mercury in Canada

Coupling the use of computer chemical speciation models and culture techniques in laboratory investigations of trace metal toxicity

Measurement and modeling of surface charge and cation binding in agricultural soil

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