title: An inter-laboratory comparison of different analytical methods for the determination of monomethylmercury in various soil and sediment samples: A platform for method improvement.
abstract: An inter-laboratory study was conducted to compare results from different analytical methods for monomethylmercury (MeHg) concentrations in 17 soil and sediment samples. The samples were collected from mercury-contaminated areas, including Minamata Bay and Kagoshima Bay in Japan, the Idrija mercury mine in Slovenia, and an artisanal small-scale gold mining area in Indonesia. The Hg in these samples comes from several different sources: industrial waste from an acetaldehyde production facility, volcanic activity, Hg mining activity, and artisanal and small-scale gold mining activity (ASGM). MeHg concentrations in all the samples were measured in four separate laboratories, using three different determination methods: Kagoshima University (Japan), using high-performance liquid chromatography-chemiluminescence detection (HPLC-CL); National Institute for Minamata Disease (Japan), using gas chromatography-electron capture detection; and Metropolitan Council Environmental Services (USA) and Jozef Stefan Institute (Slovenia), both using alkylation-gas chromatography-atomic fluorescence spectrometry detection. The methods gave comparable MeHg results for most of the samples tested, but for some samples, the results exhibited significant variability depending on the method used. The HPLC-CL method performed poorly when applied to samples with elevated sulfur concentrations, producing MeHg concentrations that were much lower than those from the other methods. Additional analytical work demonstrated the elimination of this sulfur interference when the method was modified to bind sulfur prior to the analytical step by using Hg2+as a masking agent. These results demonstrate the value of laboratory intercomparison exercises in contributing to the improvement of analytical methods.
authors.affiliation: Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kodamatani
authors.affiliation: Metropolitan Council Environmental Services, 2400 Childs Road, St. Paul, MN 55106, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Balogh
authors.affiliation: Metropolitan Council Environmental Services, 2400 Childs Road, St. Paul, MN 55106, USA.
authors.forename: Yabing H
authors.initials: YH
authors.lastname: Nollet
authors.affiliation: National Institute for Minamata Disease, Minamata, Kumamoto 867-0008, Japan.
authors.forename: Akito
authors.initials: A
authors.lastname: Matsuyama
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana 1000, Slovenia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Fajon
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana 1000, Slovenia.
authors.forename: Milena
authors.initials: M
authors.lastname: Horvat
authors.affiliation: Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan. Electronic address: tomy@sci.kagoshima-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tomiyasu
mesh_terms: D005591:Chemical Fractionation / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods*; D006046:Gold / Q000032:analysis; D007214:Indonesia; D007220:Industrial Waste / Q000032:analysis; D007564:Japan; D008628:Mercury / Q000032:analysis; D008767:Methylmercury Compounds / Q000032:analysis* / Q000737:chemistry; D008906:Mining; D017524:Slovenia; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry
chemical_list: D007220:Industrial Waste; D008767:Methylmercury Compounds; D012987:Soil; D012989:Soil Pollutants; D006046:Gold; D008628:Mercury
keywords: Inter-laboratory study; Monomethylmercury; Sediment; Soil