Recent advances in speciation analysis of mercury, arsenic and selenium

Abstract

Mercury (Hg), arsenic (As) and selenium (Se) are ubiquitous in the environment and exist in a variety of species, which have great influence on their transport, bioaccumulation and toxicity. This review presents the recent research progress in speciation analysis of Hg, As, and Se, with emphasis on enhanced cold vapor generation as interface for liquid chromatography and atomic spectrometry, speciation of volatile species in gas phase, and isotope dilution technique to improve the precision and accuracy of speciation. Hyphenated techniques to characterize the complexes of Hg and As with phytochelatins and chromatographic separation coupled with multi-collector-inductively coupled plasma mass spectrometry to measure species-specific isotopic ratios, are also briefly discussed. Mercury (Hg) and arsenic (As) are among the most highly toxic elements for humans and ecosystems and can cause serious environmental and human health problems even at low concentrations [1,2]. Selenium (Se) is an "essential toxin" for human health. It has been recognized as an important antioxidant and anti-cancer element. However, Se can also pose negative impact such as defective skin and hair loss [3]. The adsorption/uptake, transport, bioaccumulation, metabolism and toxicity of these elements strongly depend on their chemical species present in environmental and biological samples. In the environment, one species can transform to another through chemical or biological processes. For example, in anaerobic sediments, sulfur-reducing or iron-reducing bacteria can methylate inorganic mercury into highly toxic methylmercury (MeHg) [4,5]. Therefore, speciation analysis of Hg, As and Se is of great importance in order to elucidate the biogeochemcal cycle and toxicology of these elements. Speciation analysis mainly involves chromatographic separation (gas chromatography (GC) or high performance liquid chromatography (HPLC)) hyphenated with element-specific spectrometry or molecular mass spectrometry. This review presents the recent advances in speciation analysis of Hg, As, and Se based on chromatographic separation, with emphasis on enhanced cold vapor generation (CVG) as interface for LC and atomic spectrometry, speciation of volatile Hg, As and Se in gas phase, and isotope dilution technique to improve the precision and accuracy of speciation. Hyphenated techniques to characterize the complexes of Hg and As with phytochelatins and chromatographic separation coupled with multi-collector-inductively coupled plasma mass spectrometry (MC-ICP-MS) to measure species-specific isotopic ratios, are also briefly introduced.

Hg2+ion-imprinted polymers sorbents based on dithizone–Hg2+chelation for mercury speciation analysis in environmental and biological samples

“…[1][2][3][4] Among them, mercury (Hg) has become an attractive research area [1][2][3][4][5][6] because it has negative impacts on humans usually due to exposure through food, especially sh. 7,8 Its toxicity depends on its chemical forms; organic mercury compounds are generally much more toxic than inorganic mercury due to their strong lipophilic characteristics.…”

“…4,[20][21][22][23][24] In contrast to MIPs, IIPs recognize inorganic ions aer imprinting, especially metal ions. 20,21,[24][25][26][27] This recognition ability can be explained by the memory effects of polymers toward metal ion interaction with a specic ligand, coordination geometry, metal ion coordination number, charge and size.…”

Inorganic Arsenic Determination in Food: A Review of Analytical Proposals and Quality Assessment Over the Last Six Years

“…The analytical technology to be applied for the assessment of arsenic species, highlighting iAs, is continuously updated and reviewed. 43,[73][74][75][76][77][78][79][80][81][82][83][84] Nearing et al 85 reviewed additional analytical methods suitable for obtaining data to complement the information on arsenic speciation obtained when applying the methods commonly used. Among such complementary methods, electrospray mass spectrometry (ESI-MS) is most useful for identifying or complementing information on several arsenic compounds with more complex molecular structures than those corresponding to iAs species.…”

Development of a new method for analyzing free aluminum ions (Al3+) in seafood using HPLC-ICP-MS

“…Other advantages of online coupling of chromatography to ICP-MS are time saving resulting from minimization of labor-intensive steps and the speed of the separation procedures, which can prevent changes in sensitive species. Furthermore, trace contamination and analyte loss are minimized because of the closed instrumental system [20,21]. HPLC online with ICP-MS was therefore used to analyze Al speciation in the present research.…”