The present and potential future of aqueous mercury preservation: a review

Abstract

Solid-phase extraction is potentially a safe alternative to in-field dissolved Hg sampling, particularly in challenging environments.

Field method for preservation of total mercury in waters, including those associated with artisanal scale gold mining

“…21 If unpreserved or inadequately preserved, considerable losses of Hg are noted within few days of sampling and 90% of total Hg can be lost aer just 1 week. 17,18,22 In-eld monitoring of Hg in water sources is particularly challenging, due to analysis requiring sensitive detectors, which currently do not achieve adequate detection limits, 23 thus analysis in a laboratory using robust and sensitive instrumentation, such as CV-AAS and ICP-MS, is currently necessary. 19 Some emerging technologies demonstrate appropriate sensitivity but are not currently widespread or commercially available.…”

“…Degradation of the functionalised phase may result in a decrease in immobilised Hg during the loading process and therefore underrepresent the dissolved Hg concentration in the environmental samples. This is a characteristic not often explored in the literature, as typical speciation and preconcentration methods apply the cartridge immediately after functionalisation, 23 thus not requiring a storage time for the solid phase. However, to ensure representative data collection, the functionalised solid-phase must be stable during transfer from laboratory to sampling location, approximately 2 weeks between functionalisation and application in the field.…”

“…There is an identified gap in the literature to safely and reliably sample total dissolved Hg from water matrices in challenging environments. 23 Therefore, the aim of this study was to develop a robust method for the sampling and accurate measurement of Hg in water matrices based on SPE techniques. To achieve this aim, the objectives were to: (1) develop a practical functionalised SPE method to retain and preserve Hg from water matrices and for elution on return of samples to a controlled laboratory environment; (2) optimise parameters of sorption and desorption of Hg to the stationary phase for subsequent measurement; (3) demonstrate robustness of method in water matrices.…”

Atomic spectrometry update – a review of advances in environmental analysis

“…In an overview (88 references) of the preservation of mercury in water samples , King et al 52 evaluated trapping on SPE phases as an alternative to the current practice of using preservatives in bottles. The authors noted that, when using SPE, various species can be preserved in the field without the use of hazardous reagents.…”

Simultaneous Measurement of Trace Levels of Hg, As, Sb, and Bi in Coastal Seawater with a Multichannel Chemical Vapor Generation Atomic Fluorescence Spectrometer

“…Hg is well known to be ubiquitous in the environment and is one of the most toxic elements to the ecosystem and has been listed as one of the 13 priority hazardous substances under the EU Water Framework Directive. Therefore, Hg has become one of the most widely studied and monitored environmental pollutants. − It has been found that 0.15 to 2.0% ( v / v ) nitric acid, which was commonly used to store standard solution for most elements, was unsuitable for the preservation of dissolved Hg 2+ in a single-element or multielement standard solution. , In the United States Environmental Protection Agency Method 1631–2002 the preservation for Hg 2+ standard solution contains 0.5% ( v / v ) BrCl, while in the National Environmental Protection Standard of the People’s Republic of China HJ 694–2014, the preservation medium is a mixture of 5.0% ( v / v ) HNO 3 and 0.05% ( w / v ) K 2 Cr 2 O 7 . , These standards all suggest that a strong oxidizing media should be considered for Hg­(II), but other elements, such as As­(III), Sb­(III), and Bi­(III) must be preserved under reducing conditions for hydride generation in a low valence state. Until now, copreservation of Hg­(II) with other elements has not been available for simultaneous determination when the CVG process was applied as a sample introduction system.…”