Methylmercury Pathways in the Water Column and Sediments along Canada's Arctic Margin

Archived sediment samples from 25 sediment cores, which were collected along an oceanographic section spanning Canada's Arctic margin during the International Polar Year (2007-2008). All sediment samples were analyzed for Hg at INRS (Université du Québec) at no cost to NCP, and a subset of samples analyzed for MeHg at Ifremer, France. The analytical methods employed for MeHg in the sediments are based on the separation of organic mercury compounds by gas chromatography, followed by ionisation of analytes in argon plasma and Hg detection by mass spectrometry (GC-ICP-MS with isotopic dilution). Briefly, a known quantity of an internal standard (Me202Hg) is added to an aliquot of freeze-dried sediment which is then leached with 4 mL of HNO3 (6N). After centrifugation and decantation, the pH is adjusted to 4 by adding ammonia and a sodium acetate-acetic acid buffer. MeHg is then propylated by adding sodium tetrapropylborate and the Hg compound is extracted in isooctane. The analysis of propylated Hg is performed by gas chromatography (GC) coupled to a quadrupole ICP-MS. The detection limit is around 1 pmol g-1. Precision and accuracy, determined from replicate measurements (n = 6) of the CRM 405 material from IAEA, is usually better than 10%. Details are given in Feyte et al. (2010, Geochimica and Cosmochimica Acta, Vol. 82, 92-112).

Metadata Access
Creator Cossa, Daniel;Kuzyk, Zou Zou A.;Gobeil, Charles;Macdonald, Robie W.
Publisher Canadian Cryospheric Information Network
Contributor INRS-ETE
Publication Year 2015
Rights Limited
Language English
Discipline Environmental Research
Spatial Coverage (56N-72N,175W-57W)
Temporal Coverage Begin 2007-07-12T11:59:59Z
Temporal Coverage End 2008-08-12T11:59:59Z