Determination of mercury in slurried samples by both batch and on-line microwave digestion–cold vapour atomic fluorescence spectrometry

Lamble, Kathryn J.; Hill, Steve J.

doi:10.1039/ja9961101099

Cited by 30 publications

(20 citation statements)

References 7 publications

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“…For a quantitative oxidation of MeHg by BrCl at room temperature, a rather high concentration of BrCl (2.5 %) during prolonged time (several hours) was required. It was suggested that digestion of MeHg by BrCl could be promoted at elevated temperature [16], or by microwave-assisted BrCl oxidation used in the on-line method for Hg determination in slurried samples [17]. Our results (Tab.…”

supporting

confidence: 56%

Microwave-assisted determination of total mercury and methylmercury in sediment and porewater

Niessen

Fischer

1999

Analusis

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Microwave-assisted extraction methods for sample preparation have been evaluated in various environmental applications, as are total digestion for element analysis or extraction of selected organic compounds. This technique has been confirmed as a method of choice over conventional procedures for digestion of mineral and biological samples for total Hg determination [1,2,3], due to a shorter extraction time, a higher extraction efficiency and easier control of digestion parameters. Both closed and open microwave systems are used for the digestion of samples for the total Hg analyses. However, determination of the total Hg in environmental samples is not sufficient, as Hg is partly in the form of methylmercury (MeHg), which is considerably more toxic than the inorganic Hg. A particularly difficult task is the determination of MeHg in sediment, where it makes a very low percentage of the total Hg (< 2 %). Only recently, an open low-power focused microwave system has been verified as an appropriate tool for preparation of solid samples for organometallic speciation analysis [4]. It has been used for developing of the isolation procedure of MeHg in sediment based on the microwave-assisted leaching of MeHg with dilute acids [5].In this work, the application of open microwave system for the total Hg and MeHg determination in sediment and porewater is described. Microwave-assisted leaching of the total Hg and MeHg from sediment with an acid extractant, provided a rapid way of separation of these species from the matrix prior to detection by CV AFS (cold vapour atomic fluorescence spectroscopy). Microwave-assisted BrCl oxidation was proved to be more effective for the decomposition of MeHg and stable organomercury complexes in solution (distillate or porewater), as compared with BrCl oxidation at room temperature. Material and methods ReagentsAcids used were of analytical quality (HNO 3 , HCl) or suprapur grade (HCl, Merck). Hg standard was prepared from stock standard solution (1 g/L, Merck). A standard solution was prepared weekly in 10 % HNO 3 and 0.01 % of K 2 Cr 2 O 7, whereas reference standard solutions were prepared daily in 1 % HNO 3 . A reductant solution (5 % SnCl 2 in 10 % HCl) was prepared by dissolving SnCl 2 in concentrated HCl and diluting with water. The certified reference sediments used for verification were PACS-1 (National Research Council of Canada -NRCC) and CRM 580 (Community Bureau of Reference of the European Communities -BCR). 871Microwave-assisted determination of total mercury and methylmercury in sediment and porewater

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confidence: 56%

Microwave-assisted determination of total mercury and methylmercury in sediment and porewater

Niessen

Fischer

1999

Analusis

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“…Again, under optimum conditions, sample throughput was restricted by the instrumental analysis time (about 20 min per sample) rather than by the sample preparation step. Mercury was determined in environmental solid samples, employing a system with on-line digestion of the samples (LambIe and Hill 1996). In such a system, slurred samples were injected into a carrier stream of hydrochloric acid and mixed with a solution of potassium bromide-bromate before passing through a PTFE coil situated in the microwave cavity of a conventional microwave digester.…”

Section: Sample Preparation Using Focussed Microwave Ovensmentioning

confidence: 99%

Modern Strategies for Environmental Sample Preparation and Analysis

Santelli¹,

Cassella²,

Arruda³

et al. 2004

Environmental Geochemistry in Tropical and Subtropical Environments

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“…Careful evaluation of the optimum HPLC conditions for separating cationic and anionic arsenic species in a single run shows that anionic interaction or reverse-phase ion-pair chromatography is the most suitable method (5)(6)(7)(8)(9)(10)(11)(12). The organic cationic species may also be retained in the anionic column by van der Waals forces or by the counterion in the resin.…”

Section: Introductionmentioning

confidence: 99%