Details

Autor(en) / Beteiligte

• Lusilao-Makiese, Julien
• Tessier, Emmanuel
• Amouroux, David
• Tutu, Hlanganani
• Chimuka, Luke
• Cukrowska, Ewa M

Titel

Speciation of mercury in South African coals

Ist Teil von

• Toxicological and environmental chemistry, 2012-10, Vol.94 (9), p.1688-1706

Ort / Verlag

Abingdon: Taylor & Francis Group

Erscheinungsjahr

2012

Quelle

Taylor & Francis Journals Auto-Holdings Collection

Beschreibungen/Notizen

• Total mercury (HgTOT) concentrations were determined by inductively coupled plasma mass spectrometry (ICP MS) for South African Highveld coals. The distribution of Hg in coals was investigated using a four-stage sequential leaching protocol and isotope dilution/gas chromatography coupled to ICP MS (ID-GC-ICP MS). The results show that HgTOT ranged from 144 to 303 µg kg⁻¹ with a mean of 199 ± 26 µg kg⁻¹, while HgTOT leached from coals using different solvents ranged between 103 and 310 µg kg⁻¹ (mean: 218 ± 60 µg kg⁻¹). Hg leaching rates of 53–78% were achieved in crushed coals. Hg⁰, Hg²⁺, and CH₃Hg⁺ were identified in all coals. CH₃Hg⁺ in studied coals ranged between 0.1 and 0.4 (mean: 0.2) µg kg⁻¹. GC ICP MS chromatograms also showed unknown Hg peaks which were identified as other organomercury species such as ethylmercury. Modes of occurrence of Hg in coals were variable with the organic-bound (37–40%) and the sulfide-bound (37–39%) being the dominant mercury forms. Increasing the HCl concentration in the used protocol increased the amount of Hg leached (16%) during this step.